New Zealand Vintage Computer Forums

Hey all, finally gotten back into fixing vintage computers after a bit of a hiatus. Today I replaced every electrolytic capacitor on my 1983 C64 and as something interesting, I checked the values of the old capacitors.
All the 10uF capacitors were reading between 12 and 16uF, the 2200uF capacitor was 2866uF and the 470uF ones were 500uF and 522uF.

After replacing them, the C64 is so much better. I'd get the odd brown-out before, where 50hz would come through the speakers and the display would dim, the odd crash too. All fixed now!

I would suggest that with electrolytics it is more important to focus on checking ESR rather than capacitance.

I would have checked, but I don't own any equipment that could test it easily, and I don't have time to cobble something together. You're right though, in this case ESR would be the better value to check. I'll keep the old caps in case I do one day end up testing them.

I would recommend this which is what I use.
Check caps in situ (no desoldering).

I did what ZL2AOX suggested and tested the ESR. I was getting an average of 6 ohms over all of the caps (highest 11 ohm, lowest 2 ohm). Tested the new replacement caps and I had 0.06 ohm.