Bathroom Extractor Fan Repair - Capacitor Identification

[richgit]

Hi all, happy new year!

I have 4 x Vent-Axia VASF100T Bathroom Extractor fans, 2 of which have started failing within days of each other.

When the lights are on, they work fine, however when switched off (on timer over-run) they seem to immediately turn off, however upon removing the cover the fans are pulsing / twitching which suggests a failing capacitor (or resistor?) from a quick Google.

There are 2 capacitors, one clearly marked '25v 220uF' which I've already replaced, but the problem still exists so I'm assuming the other one has gone, or perhaps another component on the PCB. The larger capacitor doesn't have any obvious specification markings, but it is 8.26mm in diameter and 13mm in height. Would any of you be able to identify the specification with this information?

Other than that I'm not sure what else to try, no components seems obviously damaged / swollen / burned. I could buy new fans altogether, but they're £60-70 each so would rather repair if I can.

Thanks in advance.

 

[Nigel Goodwin]

There are 2 capacitors, one clearly marked '25v 220uF' which I've already replaced, but the problem still exists so I'm assuming the other one has gone, or perhaps another component on the PCB. The larger capacitor doesn't have any obvious specification markings,

It's pretty clearly marked as 470uF 16V in your last picture, you could get a better view by taking it out.

 

[richgit]

Thanks. Not sure how I didn't see that. Doh.

 

[sagor1]

There may be components on the underside of the board. It seems to have an AC input, but no visible diodes/rectifiers to make DC voltages for the op-amp (TL082CN). Not much else can go wrong with just the op-amp and transistor on top, so I suspect more likely input issues like a blown diode.