Fender Sidekick 10 Humming

[J M Fahey]

Cool
Remember to take the voltage readings and follow tracks/wiring.

[patlaw]

When I took another look, I noticed that the solder joints on the power module were possibly wonky, so I resoldered them. I also installed a new cap that won't fit into the cabinet. When I powered the amp up, it's perfectly quiet. It sounded like it wasn't working. So, rather than install the old cap and find it's bad, I'm getting a new one so that I don't have to disassemble this thing several more times. The TO220 thing is probably a transistor that works with the external battery. With no battery connected, it has 16 volts on each of the three legs. I'm not going to test it with a battery since I don't have one and the customer doesn't plan to use it on battery.

[J M Fahey]

Not sure I understand you:

When I powered the amp up, it's perfectly quiet. It sounded like it wasn't working.

Is it or is it not working?
Can you plug a guitar and hear it?
Do the controls work?

[patlaw]

Not sure I understand you:

Is it or is it not working?
Can you plug a guitar and hear it?
Do the controls work?

Yes, it is working perfectly, controls and all. My comment is that the amp was so quiet I thought it was dead. It was not dead. It's quiet. Thanks for helping me think this through.

[Enzo]

So we determined your cap was indeed faulty.

[J M Fahey]

Good to know.
And happy it was the cap, which is a generic component easy to replace and not a 35 y.o. 12 pin IC which needs exact same part and nothing else.

One reason I never used chipamps but always preferred discrete, even if itb takes a little more PCB size and slightly longerb to build.

Saw the obsolescence and replacement trouble caused by first the Japanese TDA something once used by Fender, such as this one (and uPC1188), TDA1514 found in Marshalls but also on others, various high power Sanken modules, even LM3875 and 3876 which "should" be replaceable by currently available LM3886 but no, they HAD to change pinout .
Any moment now and they plus TDA7293/94 will be discontinued ... like they did with very useful TDA2050

While my early 70īs amps based on 2N3055 driven by TIP31/32 can be easily repaired today.

Not complaining about LM741/LF351/TL071 and MC1458/RC4558/LF353/TL072 because each in its class kept pinout and can be freely exchanged by a modern version.

Maybe there is a lesson to be learnt there