Omega Owners Forum
Chat Area => General Discussion Area => Topic started by: jereboam on 27 December 2009, 17:55:52
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My amplifier stopped working. Just like that - no bang, no smoke, no flames. It just stopped. Checked the fuse - it had blown. Zoomed into town and just caught Maplins as they were closing. Replaced fuse. Blew immediately - no surprise there.
Anyone got any suggestions? I'm reasonably competent with a soldering iron, and I've got a multimeter. What I haven't got is enough money to buy a new one. :'( :'( :'(
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Sorry I cant help J, but I'm sure someone will
take the piss help you soon.
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Come on, give us a clue....you have an old amp thats stopped working and its blowing fuses....
Make
Model
Type
Which fuse
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Probably the pins on a valve shorted out. ;D
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He must be having his nap.
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Probably has vintage value that amp.
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Chances are that if its the mains fuse it could be a possible dead rectifier diode/bridge
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Chances are that if its the mains fuse it could be a possible dead rectifier diode/bridge
On something that age, it could be as simple as a worn power flex shorting out, but I'm no good at long distance diagnostics.
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Chances are that if its the mains fuse it could be a possible dead rectifier diode/bridge
On something that age, it could be as simple as a worn power flex shorting out, but I'm no good at long distance diagnostics.
Just thinking the same thing.
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Lol, I am hoping said person is not quite so stupid to of not checked,
I have to say that I dont agree with the 2 of you, if it was an iron, vaccum or something that was often moved, wound etc then yes.
Plus mid seventies the plastics were reasonably ok.
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Lol, I am hoping said person is not quite so stupid to of not checked,
I have to say that I dont agree with the 2 of you, if it was an iron, vaccum or something that was often moved, wound etc then yes.
Plus mid seventies the plastics were reasonably ok.
Only said 'could be'. It 'could be' a good few things.
I doubt we'll ever know.
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He must be having his nap.
No - I was off doing the IQ test.
Did that OK, but can't remember my username/password for the AVforums. :( :(
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On something that age, it could be as simple as a worn power flex shorting out, but I'm no good at long distance diagnostics.
.......Heater, Cathode, Grid, Anode......or insufficient vacuum! :P
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On something that age, it could be as simple as a worn power flex shorting out, but I'm no good at long distance diagnostics.
.......Heater, Cathode, Grid, Anode......or insufficient vacuum! :P
You forgot the top cap.
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OK
It's a Sansui AU4400, and it was the 1.5A case-mounted fuse which blew. As far as I remember, its rated at about 30w RMS per channel. Shouldn think it's got any valves in it, but from the 1975 vintage, I'd guess it's mostly discrete components.
It's unlikely to be the external connections, as nothing else in the stack has been affected.
(http://i291.photobucket.com/albums/ll307/rehaboam/au4400_1.jpg)
Beautiful!
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On something that age, it could be as simple as a worn power flex shorting out, but I'm no good at long distance diagnostics.
.......Heater, Cathode, Grid, Anode......or insufficient vacuum! :P
You forgot the top cap.
;D Thermionic-amnesia! ;)
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On something that age, it could be as simple as a worn power flex shorting out, but I'm no good at long distance diagnostics.
.......Heater, Cathode, Grid, Anode......or insufficient vacuum! :P
You forgot the top cap.
;D Thermionic-amnesia! ;)
That could be what's wrong with my valves... :)
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Sansui....very nice (or were)
How spectacular is the fuse blow?
How good are you with a DVM?
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Ok. Stick a massive piece of metal in the fuse holder and see what starts to burn. That's yer faulty bit :y
;D ;D ;D ;D ;D
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Ok. Stick a massive piece of metal in the fuse holder and see what starts to burn. That's yer faulty bit :y
;D ;D ;D ;D ;D
Well? Have you tried it yet?
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Sansui....very nice (or were)
How spectacular is the fuse blow?
How good are you with a DVM?
What's a DVM - digital volt meter? I can manage that, just about.
The fuse was severely blackened, but it must have been ancient - I think I may have replaced it once before, but I can't remember why. The replacement just blew - no significant blackening. No bang either, although I heard a rumble from the (same vintage Sansui) speakers.
I think the first thing I'll do is remove the case and look for burnt out bits. Hoovering 30-odd years of dust, bugs and other detritus out of there may help a bit.
I didn't actually see it go off - I was watching something really interesting on the TV (i.e. I'd dozed off momentarily) and the I noticed the Sky box had turned off and I had no sound through my headphones. Then I saw the light on the amp had gone out. :'(
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Ok. Stick a massive piece of metal in the fuse holder and see what starts to burn. That's yer faulty bit :y
;D ;D ;D ;D ;D
Well? Have you tried it yet?
One suspects that, ultimately, one will have to try that solution. But for the time being, one intends to adopt a more analytical, and thus less destructive, approach. :)
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Pop the lid off and post a picture of the internals
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Ok. Stick a massive piece of metal in the fuse holder and see what starts to burn. That's yer faulty bit :y
;D ;D ;D ;D ;D
Well? Have you tried it yet?
One suspects that, ultimately, one will have to try that solution. But for the time being, one intends to adopt a more analytical, and thus less destructive, approach. :)
Chicken.
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It's a bit mucky, but not as bad as I expected. I'll have a go at cleaning it after the wife has stopped watching her film and gone up to bye-byes.(http://i291.photobucket.com/albums/ll307/rehaboam/DSCF0482.jpg)
Power transistors look OK, and both the internal fuses are OK. I suspect there are more bits, possibly another board, under the metal chassis where the big transformer is mounted, but I can't play around with it until later.
(http://i291.photobucket.com/albums/ll307/rehaboam/DSCF0483.jpg)
(http://i291.photobucket.com/albums/ll307/rehaboam/DSCF0484-1.jpg)
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See those 4 diodes in the 1st picture just below the wire link by the screen print on the pcb saying 4A....measure them with a DVM set to resitance
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I can see the problem, it's that fried spider in the bottom right hand corner ;D
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I actualy think its scared of your wallpaper.....
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Set the points gap to 25 thou!!!!
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See those 4 diodes in the 1st picture just below the wire link by the screen print on the pcb saying 4A....measure them with a DVM set to resitance
Once again, it will all have to wait until madam goes to bed. I'll check them, and post the results later.
I actualy think its scared of your wallpaper.....
It's lovely wallpaper! I chose it. :) You should have seen what the wife wanted. I could not survive a Laura Ashley living room. Much prefer the aspirational Regency stripe.
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I actualy think its scared of your wallpaper.....
;D Hahahahahahaha! :-*
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I can see the problem, it's that fried spider in the bottom right hand corner ;D
That's young Arthur. I've been wondering what happened to him. RIP Arthur.
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I can see the problem, it's that fried spider in the bottom right hand corner ;D
That's young Arthur. I've been wondering what happened to him. RIP Arthur.
Young!!! He looks like he's been in there since new along with all the dust & cobwebs. He probably choked on the dust & fell onto the mains feed ;D
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I can see the problem, it's that fried spider in the bottom right hand corner ;D
That's young Arthur. I've been wondering what happened to him. RIP Arthur.
Young!!! He looks like he's been in there since new along with all the dust & cobwebs. He probably choked on the dust & fell onto the mains feed ;D
Well he was young the last time I saw him...
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I can see the problem, it's that fried spider in the bottom right hand corner ;D
That's young Arthur. I've been wondering what happened to him. RIP Arthur.
Young!!! He looks like he's been in there since new along with all the dust & cobwebs. He probably choked on the dust & fell onto the mains feed ;D
Well he was young the last time I saw him...
PMSL ;D ;D ;D ;D ;D ;D
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It's probably a capacitor somewhere they are always favorite
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See those 4 diodes in the 1st picture just below the wire link by the screen print on the pcb saying 4A....measure them with a DVM set to resitance
Once again, it will all have to wait until madam goes to bed. I'll check them, and post the results later.
I actualy think its scared of your wallpaper.....
It's lovely wallpaper! I chose it. :) You should have seen what the wife wanted. I could not survive a Laura Ashley living room. Much prefer the aspirational Regency stripe.
;D ;D splendid 8-) 8-) :y
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Diodes.
Hazy memories of A-level physics (about 45 years ago) told me that polarity was involved, so I Googled diode testing. :) There really is an amazing amount of misinformation available on the Worldwide Web :( :( :(
Anyway, I eventually worked out what I had to do.
The two diodes on the left give a reading of about 0.550 on the 2k[ch8486] scale. The two on the right seem to be open circuit, which I presume isn't right.
My very elderly analogue meter confirmed this, and, as usual, proved easier to use. Regrettably, I don't trust it completely, as it gives duff readings when used for battery testing. :( :(
Will have to clean the amp tomorrow, as I can't use the vacuum cleaner at this time of the night/morning. I'd really love to get a decent night's sleep, but it's months since I managed more than 3 hours. Usually do better dozing in front of the TV. But I'll pop up to the spare room and try to get a couple of hours now.
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OK
It's a Sansui AU4400, and it was the 1.5A case-mounted fuse which blew. As far as I remember, its rated at about 30w RMS per channel. Shouldn think it's got any valves in it, but from the 1975 vintage, I'd guess it's mostly discrete components.
It's unlikely to be the external connections, as nothing else in the stack has been affected.
(http://i291.photobucket.com/albums/ll307/rehaboam/au4400_1.jpg)
Beautiful!
Thats certaintly a classic. I remember those big flick switches from the eightes when I was growing up. :y
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Diodes.
Hazy memories of A-level physics (about 45 years ago) told me that polarity was involved, so I Googled diode testing. :) ....
Think none return valves!! ;D ;D ;D ;D
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Diodes.
Hazy memories of A-level physics (about 45 years ago) told me that polarity was involved, so I Googled diode testing. :) ....
Think none return valves!! ;D ;D ;D ;D
Indeed - so measure each one with the multimeter leads round each way and you should get conductivity in only one direction. Even better, if the multimeter has a diode test mode (little diode symbol on the switch?) it will tell you the voltage drop, which should be 0.6 v ish in one direction and off the scale in the other.
TBH, I would expect one or more to be a dead short if it was faulty, and that doesn't look to be the case.
Is that the fuse that failed on the LHS of the back panel in your photo? Did you have anything plugged into the aux. mains outputs next to it? Just wondering if something external has dragged it down?
Can you trace the mains input wiring into the mains transformer and measure the resistance across the primary of the transformer, and also between that and chassis?
Next step - does the secondary of the mains transformer have a connector where it feeds the amplifier PCB? If so, can you power up the transformer with the connector disconnected - without the fuse popping?
Kevin
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Indeed - so measure each one with the multimeter leads round each way and you should get conductivity in only one direction. Even better, if the multimeter has a diode test mode (little diode symbol on the switch?) it will tell you the voltage drop, which should be 0.6 v ish in one direction and off the scale in the other.
The two diodes on the left give a reading of about 0.550 on the 2k[ch8486] scale.
TBH, I would expect one or more to be a dead short if it was faulty, and that doesn't look to be the case.
The two on the right seem to be open circuit, which I presume isn't right.
When a rank amateur of advanced years uses the term "open circuit" at 05:48 it should be obvious that he just read it somewhere and confused it with the term "dead short", which on this occasion I won't take to be a personal insult. The readings for the two two diodes on the right were both zero - no resistance. Many apologies for the confusion.
Is that the fuse that failed on the LHS of the back panel in your photo? Did you have anything plugged into the aux. mains outputs next to it? Just wondering if something external has dragged it down?
Yes. How can you recognise these items from the picture - you must have looked at quite a lot of them to identify the stuff so quickly. Never had anything plugged in there - they are American style sockets.
Can you trace the mains input wiring into the mains transformer and measure the resistance across the primary of the transformer, and also between that and chassis?
Not at the moment. All the transformer connections are underneath the chassis plate on which it is mounted. I've just had another look, and it seems that that area is quite easily accessible by removing the the base of the casing - four screws. Unfortunately, this means I've got to remove the amp completely from the "hi-fi unit" in which it lives, which in turn means scrabbling about on the floor in an attempt to extract the mains cable from the rat's nest carefully designed wiring scheme connecting the 11 or so TV and audio components crammed in there. As my arthritic knees are playing up something rotten today, it will have to wait until the lad comes home from his "walk" - I think he's gone for a smoke.
Next step - does the secondary of the mains transformer have a connector where it feeds the amplifier PCB? If so, can you power up the transformer with the connector disconnected - without the fuse popping?
Kevin
Thanks a helluva lot to all of you for all your help. :) :) :)
Sorry about the wallpaper... :(
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The readings for the two two diodes on the right were both zero - no resistance. Many apologies for the confusion.
Ahh. Now we're getting somewhere. Sounds like that might be the problem.
Yes. How can you recognise these items from the picture - you must have looked at quite a lot of them to identify the stuff so quickly. Never had anything plugged in there - they are American style sockets.
::) :-[ ;)
Not at the moment. All the transformer connections are underneath the chassis plate on which it is mounted.....
Well, I wouldn't worry too much. If 2 of the diodes are reading 0 ohms I think diode failure might indeed be your problem.
Thanks a helluva lot to all of you for all your help.
No problem.
So, how are you with a soldering iron? ;)
Kevin
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So, how are you with a soldering iron? ;)
Kevin
Used to be OK, but I'm cautious about PCBs. From what I can see, it's all been hand-soldered, so it should be possible. (I don't actually mean hand-soldered, but it definitely hasn't been built using the techniques they use today - can't remember the right term.)
Mind you, my shaky hands and deteriorated eyesight are going to slow me down a bit! :( Definitely a kitchen table job.
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It's probably a capacitor somewhere they are always favorite
Agree with Jimbo, check any capacitors. Tend to fail with age. (from someone who trained in electronics 40 years ago & has forgotten it all!!!)
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Used to be OK, but I'm cautious about PCBs. From what I can see, it's all been hand-soldered, so it should be possible. (I don't actually mean hand-soldered, but it definitely hasn't been built using the techniques they use today - can't remember the right term.)
Mind you, my shaky hands and deteriorated eyesight are going to slow me down a bit! :( Definitely a kitchen table job.
Well, you could just change the diodes. Not sure what the existing ones are but something like a 1n5402 or better ought to do the job (Maplin code QL83E). Make sure you get them the same way round as the existing devices.
Kevin
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Used to be OK, but I'm cautious about PCBs. From what I can see, it's all been hand-soldered, so it should be possible. (I don't actually mean hand-soldered, but it definitely hasn't been built using the techniques they use today - can't remember the right term.)
Mind you, my shaky hands and deteriorated eyesight are going to slow me down a bit! :( Definitely a kitchen table job.
Well, you could just change the diodes. Not sure what the existing ones are but something like a 1n5402 or better ought to do the job (Maplin code QL83E). Make sure you get them the same way round as the existing devices.
Kevin
Right! The lad has carefully sorted out the wiring (he even labelled the wires) and the beast is on the living room floor. The next job is to clean it up, remove the base panel and clean up what's under there. Then I can remove the two dodgy diodes and take them down to Maplins to see if they can match them. If not, I'll just get the type you mentioned, the 1n5402. According to the Maplin's website, Ipswich has 5 in stock, so I'll probably clean them out - it's a long time since I soldered anything onto a PCB, so I may incinerate the first one. Hope I don't damage any other components. I've got a solder sucker somewhere, so I think it might be sensible to have that on hand before I start, but I should be able to manage without. I'll get the lad to assist.
By the way, when you say "1n5402 or better", what does better mean? The 1n5402 is rated at 200v but there are others with higher voltages. Apart from that, it looks to me like "a diode is a diode is a diode". OK, rectifier diodes. I appreciate that there are other types. :) :) :)
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Yep, I meant 200v PIV or better. Without knowing the amp in question I would guess the DC supply is no more than 50 or 60 volts and, as a rule of thumb, the diodes will see roughly double that so 100v might be a bit marginal, so next one up. Of course, if you end up with 800v devices it won't hurt.
I would be inclined to replace all 4 diodes while I'm there. The originals look like pretty puny devices.
Kevin
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Yep, I meant 200v PIV or better. Without knowing the amp in question I would guess the DC supply is no more than 50 or 60 volts and, as a rule of thumb, the diodes will see roughly double that so 100v might be a bit marginal, so next one up. Of course, if you end up with 800v devices it won't hurt.
I would be inclined to replace all 4 diodes while I'm there. The originals look like pretty puny devices.
Kevin
It's actually a dual-supply unit - you can run it off a 117v DC supply as well, I think. At least, that's what it says in the manual - still got it after all this time - amazing. The 1.5A fuse should be replaced with a 2A fuse if running on 117v, it says on the back.
Replacing all 4 diodes seems like a good idea - I was going to ask you about that. :)
Will let you know how I get on a bit later. :) :) :)
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I'm with the capacitor argument. There are some big electrolytics in there and they like to dry out over time. Possible they have taken the diodes out so buy extras if you're replacing them first!
I would remove the capacitors and check them with the DMM. Just don't keep the soldering iron on the copper tracks for too long or they'll lift.
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I agree that any electrolytic that old would be a concern. If it were mine I'd probably be replacing them as a matter of course, TBH. At least, it's worth looking for any signs that the capacitor cans have started to bulge.
<squeamish look away now> I actually have an extension lead with a bulb holder wired in series for firing up devices like this after repair. Stick a 60w bulb in series with it and it limits the fault current so, if something else is wrong, you can investigate it without "letting the smoke out".
Kevin
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I agree that any electrolytic that old would be a concern. If it were mine I'd probably be replacing them as a matter of course, TBH. At least, it's worth looking for any signs that the capacitor cans have started to bulge.
<squeamish look away now> I actually have an extension lead with a bulb holder wired in series for firing up devices like this after repair. Stick a 60w bulb in series with it and it limits the fault current so, if something else is wrong, you can investigate it without "letting the smoke out".
Me too! :y.....a variac and an in-series lamp base (used with a variety of wattage lamps).
Sadly, I`ve had too much experience with 'smoke generators'. :P
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As I said, I'm going to clean Maplin out of diodes. I'll replace the two duds, then test. If all is OK, I'll replace the other two. If it's not, then I've got spare diodes for attempt 2.
The big electrolytics all look good, and I've felt all round them - no lumps or bumps. I wouldn't have the first idea how to test them anyway.
Do I need to use your suggested light-bulb technique? I haven't got smoke, there's no smell of burning anywhere and the major symptom is a blown fuse. The fuses come in packets of 10 and I've got 9 left! :)
But it's all on hold for today - I'm trying to work out how to remove the headlamp unit from a Peugeot 205 - all the wiring seems to have fallen off the back and it's completely inaccessible because of the fuse box bracket. And it's freezing and drizzling out there. And the local garage aren't answering the phone. :( :( :(
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When I said freezing, I hadn't read the weather bulletin from our Snowdonia correspondent. :(
My duff headlamp and drizzle pale into insignificance compared with a busted radiator and 12" of snow!
Good luck out there! :) :) :)
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As I said, I'm going to clean Maplin out of diodes. I'll replace the two duds, then test. If all is OK, I'll replace the other two. If it's not, then I've got spare diodes for attempt 2.
The big electrolytics all look good, and I've felt all round them - no lumps or bumps. I wouldn't have the first idea how to test them anyway.
Do I need to use your suggested light-bulb technique? I haven't got smoke, there's no smell of burning anywhere and the major symptom is a blown fuse. The fuses come in packets of 10 and I've got 9 left! :)
But it's all on hold for today - I'm trying to work out how to remove the headlamp unit from a Peugeot 205 - all the wiring seems to have fallen off the back and it's completely inaccessible because of the fuse box bracket. And it's freezing and drizzling out there. And the local garage aren't answering the phone. :( :( :(
Faithful DMM on a lowish Ohms range. Connect red lead to positive and black lead to negative (probably best to short capacitor to make sure it's discharged first). DMM reading should start low and whizz up to very high Ohms or overload. A lot of old analogue MMs put positive out on the black lead and vice versa but at that low voltage it probably wouldn't hurt a big fat cap like that. If it sits at a steady low resistance reading then it's kapputt.
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As I said, I'm going to clean Maplin out of diodes. I'll replace the two duds, then test. If all is OK, I'll replace the other two. If it's not, then I've got spare diodes for attempt 2.
The big electrolytics all look good, and I've felt all round them - no lumps or bumps. I wouldn't have the first idea how to test them anyway.
Do I need to use your suggested light-bulb technique? I haven't got smoke, there's no smell of burning anywhere and the major symptom is a blown fuse. The fuses come in packets of 10 and I've got 9 left! :)
But it's all on hold for today - I'm trying to work out how to remove the headlamp unit from a Peugeot 205 - all the wiring seems to have fallen off the back and it's completely inaccessible because of the fuse box bracket. And it's freezing and drizzling out there. And the local garage aren't answering the phone. :( :( :(
Faithful DMM on a lowish Ohms range. Connect red lead to positive and black lead to negative (probably best to short capacitor to make sure it's discharged first). DMM reading should start low and whizz up to very high Ohms or overload. A lot of old analogue MMs put positive out on the black lead and vice versa but at that low voltage it probably wouldn't hurt a big fat cap like that. If it sits at a steady low resistance reading then it's kapputt.
Agreed, but unless the capacitor is isolated from the rest of the circuitry you will get misleading results. Disconnecting the wire(s) from one terminal on the cap will be ok to give access to both terminals for this test to be of the capacitor only - which is whats needed. You can resolder it back on afterwards.
HTH
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OK. I've removed 2 diodes, a section of PCB track and a chunk of my index finger.
Only one of the diodes survived. When I said at the start that the boards looked like they had been soldered by hand, I think I may have been absolutely spot on. All the component leads have been passed through the board and bent over before the solder has been applied. They are an absolute pain to remove. Years ago, I replaced my chisel shaped soldering iron with a more delicate pointed one. It's absolutely useless for this sort of job - it takes forever to transfer enough heat to melt the solder boulders holding the components in place.
And to make it worse, I can't find my thin-nosed pliers. I have 3 pairs. They've all gone. I had to go next door and borrow some from my neighbour. I'll have to do a small re-equip when I go to Maplins tomorrow. And heaven knows where the solder sucker has gone. Found the box and the spare nozzle, but the tool iself has gone awol.
And all the bl**dy lights just went out...
Back soon.
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Lights on again. It was the new bulb I put in the light fitting in the hall last week. Wife complained it was too bright, but it was exactly the same bulb as the other two in the fitting.
So, as I was saying before I was so rudely interrupted, the two dud diodes are out. One has "IR5A" on it and the other "IR5B". Do these numbers signify anything to anyone? Google reveals nothing.
Do I still replace them with 1N502s?
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OK. I've removed 2 diodes, a section of PCB track and a chunk of my index finger.
Only one of the diodes survived. When I said at the start that the boards looked like they had been soldered by hand, I think I may have been absolutely spot on. All the component leads have been passed through the board and bent over before the solder has been applied. They are an absolute pain to remove. Years ago, I replaced my chisel shaped soldering iron with a more delicate pointed one. It's absolutely useless for this sort of job - it takes forever to transfer enough heat to melt the solder boulders holding the components in place.
And to make it worse, I can't find my thin-nosed pliers. I have 3 pairs. They've all gone. I had to go next door and borrow some from my neighbour. I'll have to do a small re-equip when I go to Maplins tomorrow. And heaven knows where the solder sucker has gone. Found the box and the spare nozzle, but the tool iself has gone awol.
And all the bl**dy lights just went out...
Back soon.
That was how I was taught to mount components for flow soldering before automatic insertion machines came along!
If you know a component is duff then cut the lead on the non-solder side and the remnant will fall out when you melt the solder.
What voltage is printed on the fattest capacitor in the middle of the board? [edit](Have found out by Googling that it is 2200uF 50V so you shouldn't need wonder-diodes) BTW the IRxA/B are probably circuit references on the board? not component part no.[/edit]
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I'm impressed with this thread.
Help and advise on electrickery repair & diagnosis from afar! :y :y :y
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OK. I've removed 2 diodes, a section of PCB track and a chunk of my index finger.
Only one of the diodes survived. When I said at the start that the boards looked like they had been soldered by hand, I think I may have been absolutely spot on. All the component leads have been passed through the board and bent over before the solder has been applied. They are an absolute pain to remove. Years ago, I replaced my chisel shaped soldering iron with a more delicate pointed one. It's absolutely useless for this sort of job - it takes forever to transfer enough heat to melt the solder boulders holding the components in place.
And to make it worse, I can't find my thin-nosed pliers. I have 3 pairs. They've all gone. I had to go next door and borrow some from my neighbour. I'll have to do a small re-equip when I go to Maplins tomorrow. And heaven knows where the solder sucker has gone. Found the box and the spare nozzle, but the tool iself has gone awol.
And all the bl**dy lights just went out...
Back soon.
That was how I was taught to mount components for flow soldering before automatic insertion machines came along!
If you know a component is duff then cut the lead on the non-solder side and the remnant will fall out when you melt the solder.
What voltage is printed on the fattest capacitor in the middle of the board? [edit](Have found out by Googling that it is 2200uF 50V so you shouldn't need wonder-diodes) BTW the IRxA/B are probably circuit references on the board? not component part no.[/edit]
Sorry, not been at the computer.
Nearly right - it's actually 2000µF and the voltage is 63WV. "WV" is new to me, and Google eventually revealed that it means Working Voltage. The two smaller ones are 1500µF at 50WV. Not that I know anything about it, but I'd more or less come to the same conclusion about the IR numbers. TBH, I couldn't actually see the markings - my son told me there was something there and I had to get a magnifying glass to confirm what he could read.
The soldering technique is that which I used when I used to put together kit radios as a teenager - never been an outdoor type and I needed a more interesting hobby than stamp collecting. I'd forgotten how to remove components - used to cannibalise stuff I bought from the War Surplus shops on the Edgware Road.
I'll go and get the diodes, some pliers, a new soldering iron and a solder sucker, just in case I have to remove the big capacitors. As somebody on here said the other day, the best way to find something is to buy a replacement for it. :)
Thanks once again for all the help.
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Ahh! War surplus shops on Edgeware road!" Those were the days!
Went looking for Henry's for old time's sake when we were last in London, much to Mrs. KW's protest. Walked ruddy miles up Edgeware road looking for it to no avail. Got home and checked their web site, and they've moved a bit further up. >:(
Kevin
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Ahh! War surplus shops on Edgeware road!" Those were the days!
Went looking for Henry's for old time's sake when we were last in London, much to Mrs. KW's protest. Walked ruddy miles up Edgeware road looking for it to no avail. Got home and checked their web site, and they've moved a bit further up. >:(
Kevin
Yeah! Henry's was the place ;D ;D ;D. I used to live just round the corner for a couple of years and I went to school nearby, so I could go in and browse and drool over all that stuff I couldn't quite afford. All those nasty brittle black plastic cases and those "deaf aid" earphones. If you were dead lucky you might just about pick up 208 on a clear night with the wind in the right direction. :) :) :)
All ruined when the Japs started flooding the market with cheap trannies. :( :( :(
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I'm impressed with this thread.
Help and advise on electrickery repair & diagnosis from afar! :y :y :y
And no-one's butted-in with warnings about dealing with burns and electrocution!
Wahaaaaay! I feel Freeeeeee!
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I'm impressed with this thread.
Help and advise on electrickery repair & diagnosis from afar! :y :y :y
And no-one's butted-in with warnings about dealing with burns and electrocution!
Wahaaaaay! I feel Freeeeeee!
;D ;D ;D ;D ;D ;D
'Elf 'n' Safety STOPS here .......... ;) ;D ;D