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Is this Circuit board normal
Posted by: SE30_Neal on 2019-04-27 12:24:39
Hi Guys,

i brought a used a/b analogue board/sony psu combo as a temporary replacement for my se/30’s whilst i recap and clear up my original items. The replacement board is from an SE which I believe is identical? Basically I’ve been experiencing some minor shimmers/flickering especially when cold (3-4 months now) so i thought it was about time to re-cap both my analogue board and psu as the motherboard had already been recapped some time ago, including a new battery. Question is psu board looks a little unusual, at first i though it was spilt liquid of leaking capacitors yet on inspection the caps all look great; no swelling, no residue, no corroded tracers. I used a q-tip to clean the edge and nothing came off. Its almost like varnish. Is this normal on the sony PSU?

neal

2A7341EB-087E-487A-B257-65884A941E71.jpeg

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Posted by: unity on 2019-04-27 13:22:26
Looks like Conformal coating. But at a quick glance, I see a couple joints that could be cold. Inspect for could joint and reflow with fresh solder first.
Posted by: SE30_Neal on 2019-04-27 13:38:31
Looks like Conformal coating. But at a quick glance, I see a couple joints that could be cold. Inspect for could joint and reflow with fresh solder first.
Thanks Unity. I thought it may have been a coating. Not so great that you can see some issues :/  I’ve never soldered before so this will be my first time when i re-cap. Replacing caps I’m fine with but Cold joints? Not sure what I’m looking for, which ones could you see?

thanks

neal
Posted by: AlpineRaven on 2019-04-27 15:37:25
Do a small test - get IPA on cotton bud, and give it a small rub - if something comes off then you know something isn't right but if it doesn't then its the coating.
Cheers

AP
Posted by: unity on 2019-04-27 16:18:54
If you can solder caps you can reflow a cold joint. Just tap the iron to it to melt the solder and apply a little more fresh when you do. Takes 2 second. Look for joints that have cracks in them, usually circular around the component's leg. Start on where the connectors connect first.
Posted by: SE30_Neal on 2019-04-28 00:43:00
Thanks Alpine, yes did that and nothing came off thankfully. So how do you tell whats a cold joint or not or should i just reflow every joint just encase? Like i said as a novice I’m not really sure what I’m look for but happy to try it.

cheers
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