Technics SU-V55A amplifier fault

[Pineappled73]

No sound output but everything else seems to work fine.Any tips on how to repair my favourite amp please.

 

[Grador]

Hate to say it, but if you are soliciting general "tips" than this project is likely far beyond your ability. Amplifiers are a difficult thing to work with. Your only hope on this front is to search around to see if there is a very common failure that someone has written up how to remedy. Otherwise, it usually costs more to have an amplifier professionally repaired than it's worth, often more than it would cost to get a comparable replacement.

 

[croseiv]

If it were me, I'd open it up and just take a look at the internals to make sure nothing was obviously amiss like a blown capacitor ot damaged resistors, transistors etc that looks scorched or burnt. But also, I agree that it is a rather old piece of equipment, and it may be time for something newer. Even if you did see something obviously wrong, it would cost more to get it fixed than it is worth.

 

[M Code]

Hate to say it, but if you are soliciting general "tips" than this project is likely far beyond your ability. Amplifiers are a difficult thing to work with. Your only hope on this front is to search around to see if there is a very common failure that someone has written up how to remedy. Otherwise, it usually costs more to have an amplifier professionally repaired than it's worth, often more than it would cost to get a comparable replacement.

Older amplifiers frequently used multiple fuses... and fuses can open due to age....
Pop off the top/bottom covers and check things out...

Here is a link to help U out with the Service Manual..

Just my $0.02...

 

[jeromach]

I happened to just today receive a "broken" SU-V55A. It appeared not to be broken, just the power switch knob was missing, so that it was difficult to poke the lever thorugh the small hole where the knob used to be.

Anyway, I took it apart just to clean the innards and to be frank, I didn't see any fuses. It's unlikely there are no fuses, so perhaps they are hidden quite deep inside.

It's quite a nice machine, good sound and enough power, don't throw it away to quickly. There's not so much that can break, these amps are made quite solid. Well, unless there have been preliminary signs (heating up too much is the worst).

First thing to check is whether the sound of a clicking relay can be heard when switched on. If so, also the "current drive" light should switch on (next to the voltage control light). If both work most likely it's something simple; speaker switch not on or on B while speakers on A. Another possibility is dirt in the switches or potmeters. What will help sometimes is engaging them a couple of times.

If only the voltage control light comes on, then the trouble is more serious, professional advice then might be needed. If no lights at all come up the net cable/connection should be tested.

If needed I can send the service manual of this machine, then send me a PM