Not sure what the problem is from a repair standpoint. I buy the chip and replace it. Most chips are very inexpensive, especially those used in mass produced consumer electronics. But by and large, the things that fail are chip transistors, driver chips etc that are readily available and easy to replace.
I bought one of those CHiP dogs online for the holidays. The tiny little watch controller it came with did not accept a charge. After working with their online customer support to get an RMA, I decided it might just be easier to fix it myself. I’m not explaining to a 7 year old that the new toy he just got will be fixed in 7 weeks! Opened it up, lots of 0402 sized SMT parts etc. Reverse engineered the whole circuit, found likely suspect in way they designed the battery logic. Jumpered around the protection circuit and viola! started taking a charge. If the battery goes completely DEAD, the protection will not allow it to charge. It went dead sitting on a shelf apparently. The CS finally came through and I have TWO functioning watches. All of the parts inside are commercially available and although very small, easy to access and replace. YMMV.