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turrican9 · 02 January 2022, 11:33

I took a closer look at one of my 'prestine' A500 boards that I recapped a few years ago. I now use reading glasses and should probably have started using them years ago. I found corrosion under the two 3300uF caps for the video output. The vias, and a few traces had corrosion on them. I did some scraping, fiberglasspen and applied UV reactive PCB paint to the affected areas. Then I resoldered the caps.

This leakage was from the old caps, but I didn't look close enough when I did this board the first time. As I said I should have used the reading glasses several years ago.

Also, an A500 Plus I was fixing up for a dude had quite bad audio output. Probably because of the audio caps are dried out.

I have now changed my mind about this matter and I think every A500 should be recapped. If the two big 3300uF caps leak you might not see it without removing them first. Also, you might not see any issues even if they are leaking. The youngest A500s are at least 30 years old now. And the caps will start to dry out. Most likely the two 3300uF ones are more prone to leak. While the other ones will usually start to dry out. Could lead to various problems, like bad sound or even kill RAM chips. There is one cap that smooths the +5v for the RAM chips.

So I do not regret recapping my A500s anymore.

02 January 2022, 11:33	#18
turrican9 Registered User Join Date: Apr 2015 Location: Norway Age: 47 Posts: 893	I took a closer look at one of my 'prestine' A500 boards that I recapped a few years ago. I now use reading glasses and should probably have started using them years ago. I found corrosion under the two 3300uF caps for the video output. The vias, and a few traces had corrosion on them. I did some scraping, fiberglasspen and applied UV reactive PCB paint to the affected areas. Then I resoldered the caps. This leakage was from the old caps, but I didn't look close enough when I did this board the first time. As I said I should have used the reading glasses several years ago. Also, an A500 Plus I was fixing up for a dude had quite bad audio output. Probably because of the audio caps are dried out. I have now changed my mind about this matter and I think every A500 should be recapped. If the two big 3300uF caps leak you might not see it without removing them first. Also, you might not see any issues even if they are leaking. The youngest A500s are at least 30 years old now. And the caps will start to dry out. Most likely the two 3300uF ones are more prone to leak. While the other ones will usually start to dry out. Could lead to various problems, like bad sound or even kill RAM chips. There is one cap that smooths the +5v for the RAM chips. So I do not regret recapping my A500s anymore.