Amiga hardware info, help and support with a focus (but not limited to) North American NTSC experiences. Open to all.
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webman

by webman posted Fri Jun 21, 2019 9:16 am

I recently received an A1200 that has no audio on the left channel. I think its a bad capacitor (has had a recap) and was wondering if I can bypass the capacitor to test the theory. Will this cause any issues?
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EzdineG
Springfield, MO

by EzdineG posted Fri Jun 21, 2019 10:57 am

Did you check the audio connectors? Can you confirm you're not getting a mono output because one is broken?

If either of those caps are bad, you won't hear anything for the side. I would be more inclined to swap in from the good side than short it out since it is a direct line to the Op Amp.

If the cap is good, start tracing forward from pins 33/34 on Paula with a scope or cheap analyzer.
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webman

by webman posted Fri Jun 21, 2019 8:24 pm

If I put the cable in part way I get sound for both channels on the speakers, but of course it is just the right side audio on both. Cable is good.
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Zippy Zapp
CA, USA

by Zippy Zapp posted Mon Jun 24, 2019 8:15 am

I had an A500 that lost a channel and it was the solder joints on the RCA jack. They were cracked. New solder and all good to go.
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Lorfarius
UK

by Lorfarius posted Wed Jun 26, 2019 1:51 am

Sounds like the caps to me. There's an article about it on my site plus a link to a UK based chap called AmigaPassion who has an amazing reputation. Quite cheap too and will do it through eBay if you want buyer protection:

Amigarama Recapping Services

He did my A1200 last year and couldn't be happier.
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Acill

by Acill posted Sat Jun 29, 2019 4:38 pm

More than likely its not the caps. When you only get one side like that the amiga has stuff in its audio layout that plays mono when you only have one cable in. I would bet one or both audio DACs are bad or the traces to them and under them are bad from cap leakage. I see this all the time and is one of the first things I check before I do work on machines. Testing sound first lets me know both sides are good.

Do you know where the DAC chips are? If you use Amigapcb.org and follow the lines with a meter you will know very quickly if they are open or shorted. If you need help let me know. I can walk you through it. I am in Australia but can still look in and get back with you.

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