Hi all. I have just recapped a WM-2091 - I only did the cylindrical silver electolytic caps, not the black rectangular ones that lie on the side. The initial issue was that I had no audio at all - just some very faint buzzing and crackling, regardless of volume, regardless of any of the switch positions (dolby/tape type/mega bass etc). There was 0 audio signal - not even a faint one. After replacing all the silver cylindrical caps, I now have audio on both channels - but left is very faint. This is my first attempt at recapping so possibly I did kind of a crap job... but I'm wondering if anyone could point me in the right direction regarding getting the left channel audio to work properly. I've reflowed the headphone jack solder points, and I've double checked the head ribbon cable is also not the issue. Thanks!
It's not uncommon for leakeage to corrode traces on these models. Seen breaks at the contact between trace and capacitor pad, usually not visible to the naked eye. Also, the capacitors sitting on a side also need to be replaced. For this you have 2 options: SMD tantalum or THT electrolytic with bent legs. C104/204 (which are in the feedback path of head preamp) are different: one is cylindrical, one sitting on one side. C104 is left channel and it's the one that hasn't been replaced, so it's likely this is your problem.
Thanks for the reply @Valentin! I'm quite sure there's no corroded traces, not that I could see, but I'll have another look carefully. But also I didn't replace C104, only the cylindrical ones - so I'll give this a go. Does it have to be SMD tantalum/bent legs electrolytic or can something like this work (assuming I can get it attached to the pads somehow): https://www.mouser.co.uk/ProductDetail/80-EDK226M004A9BAA
This SMD electrolytic can't be mounted on a side and vertically it would interfere with the mechanism. I would use something like this instead: https://www.mouser.co.uk/ProductDetail/KYOCERA-AVX/F930J226KAA?qs=a5AWWN0nKwaKKODYsNGytw== If you want to have the same capacitor for both L and R channels, use SMD tantalum for both. These 1206 footprint are much smaller than original and can fit in both footprints (vertical and mounted on a side).
Fixed it! Turns out the main problem was with C114 near the power switch (red circle). I found some normal cylinder capacitors and had to get a little creative to achieve the same clearance as the sideways ones, but it worked. Perfect sound from both ears now, even the residual buzzing has disappeared. Thanks @Valentin
