[forgotacc240419]

Oh yeah that's way beyond me! I might do a mini to micro mod first, that seems relatively quite easy

The common headphone jack issue is that one of the pins comes loose very easily but that's a very simple fix of adding some extra solder. Beyond that the audio port gradually gets looser to the point headphones will very easily fall out; I think if you just never remove the headphones this will be much less likely to happen.

The main failures I've seen on eBay are: - dead battery (these are often in amazing condition otherwise because they were bought and hardly used) - loose audio jack (simple solder fix but may have the looseness issues) - broken membrane buttons (probably not very fixable?) - faded screen (probably has lots of other issues but generally usable)

[namuol]

Yeah the buttons are actually tactile switches - it was hard to find ones that fit but eventually I found a good match on Ali express. You want 4.8x4.8x0.55mm smd thin film tactile switches. [1]

Only one button was malfunctioning but I replaced them all since they looked pretty worn.

If you’re thinking of switching to micro usb you might as well try usb-c. AFAIK you’ll still need to deal with alignment issues. The resistors are only necessary if you want to use modern PD chargers - they make little boards with these attached already but it may be impossible to fit one of those.

[1] https://www.aliexpress.us/item/3256806815314132.html

[forgotacc240419]

Probably worth posting your work somewhere, I feel like there's probably a subreddit or two that would be interested (maybe the Rockbox forum too?).

Could definitely make a decent markup buying broken ones and reselling them all fixed up too; I got seven "broken" ones a few months ago on eBay for $20 and almost all of them just had dead batteries