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Recapping — Done Right, and Done Wrong

Photos from the bench. What a leaking capacitor leaves behind, what ‘doing it right’ looks like, and what someone’s ‘complete recap’ actually turned out to be.

‘Bad caps.’ ‘Recapped.’ ‘All new capacitors.’ You hear those an awful lot. Just what are they supposed to mean — and what should they mean? There is a right way and a wrong way to do just about anything, and this holds true with replacing capacitors. Too often, it means that only a few capacitors were actually replaced, when you were told that they were ALL replaced, or that the unit was simply ‘recapped’. The photos below show both sides of the coin: how it shouldn’t be done, and how it should.

New to ‘bad caps’? Here’s what happens inside one →

1. What a leaking capacitor leaves behind

Brown electrolyte residue ringing the solder pads under a capacitor that has been removed from a circuit board — This is what you see under a removed capacitor from the AG-1980 Display board. That ring is the glycol — the first thing to seep out of the capacitor’s seal. The bad stuff comes later, when the salts follow it out.

You will not see this from the top. The capacitor looks fine, the deck works, and the ring is underneath, out of sight. The only way to know is to take the part off and look — which is why I replace all of them and not just the ones that look bad.

2. The same two pads: found, cleaned, recapped

Circuit board pads coated in dark electrolyte residue, before cleaning — Found

The same two pads after cleaning, with bare board and silkscreen visible — Cleaned

The same spot on the board with new long-life capacitors fitted flat to the board — Recapped

Same two pads, same spot, three stages. Each pad gets cleaned before a new capacitor goes in. Leave the bad stuff on the board, under the new part, and you’ve started another clock ticking down on your machine.

3. What “completely recapped” sometimes means

Six mismatched through-hole capacitors standing on bent leads over surface-mount pads on an AG-1980 timebase corrector board, one lying on its side, beside the untouched original parts — The owner of this AG-1980 was told it had been completely recapped. Look closely: SIX of the THIRTY-FOUR capacitors on this TBC board were touched, and the other twenty-eight are the originals. The six that were done are cheap Chinese parts, an inferior grade, and the wrong type to begin with. This ‘technique’ is all too common, I’m afraid.

Those are through-hole capacitors standing on bent legs over pads that were meant for surface-mount (SMD) parts. They allowed the machine to function — but the picture quality suffered because of the sloppy work. ALL OF IT — the new and the old — has to come off before this board can be recapped properly. There are approximately 250 capacitors in this machine, standard electrolytic and SMD electrolytic both — and EVERY ONE OF THEM gets replaced!

4. What it should look like

An AG-1980 display board after a full recap, with new blue long-life capacitors sitting flat and clean pads with no flux residue — The finished board. Long-life, Japanese capacitors from Panasonic. Every one sitting flat and proud where the factory put them. Pads cleaned, nothing left on the board that shouldn’t be there. Take the cover off your deck when it comes back — I insist — and this is what you’ll find.

This is one board of many inside an AG-1980. The full job, board by board, is on the Bullet Proofing page →

Do it, and do it right.

Making repairs last is what we do!

Got an AG-1980 or AG-5710 that somebody already “recapped”? Send it in — I’ll tell you exactly what was done and what it needs before any work begins.

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