Reviving a fried player--Hifiman HM-601

[Technical Petting]

I managed to fry my favorite portable player (Hifiman HN-601) by forgetting to switch a shared charger back to 5V, instead giving it 3-4 seconds of 12V before realizing my mistake. So since it won't power on anymore, I figure I have nothing to lose by doing my best to repair it, and hoping for enough good luck along the way to get me over the finish line. It wouldn't be my first miracle repair this month, even 🙂

I've got it disassembled, and unfortunately none of the compnents are visually damaged (should I have given it more time at 12V? I'm joking NOW, but I haven't ruled it out as a last resort!)(I do know better than to try this with a Lithium battery, but I don't know better than trying it with anything else)

What components, if any, can I assume to be faulty? I'd think the battery would be a good place to start, and I'm sure I have another 3.7V one to try, and I'd only be a little surprised if that was all it took. But when it isn't, what then?

I don't know how helpful this will be, but here are photos of all relevant circuitry:


Did they attach correctly?

Anyway any help is appreciated
--pete

 

[abraxalito]

A quick scan of your pics shows up some discolouration to the north and east of the 8 pin IC in the switching regulator region on pic number 4. Down at the bottom just above the inter-board connector. It would make sense that there would be a boost reg there which could have been over-voltaged.

 

[Technical Petting]

Thanks for taking a look abraxalito! Do you mean toward the bottom of the pic towards the center, just left of the C9 rectangle?

 

[kevinkr]

I'm looking at C9 and that component looks like it might have overheated. Surrounding components are suspect as well.

Try to identify whether there is a picofuse or similar somewhere on one of the boards that may have opened.