I have the same problem with the PSP Go. I've tested all the fuses and thoroughly cleaned the motherboard, but nothing makes the battery charge. I've been removing the battery and charging it externally, which has been the only solution so far...
You ever try soaper powder/qauludes? I did once and like a dumbass drank beer on top of taking, I woke up laying in my backyard in the pouring rain, it knocked me out. I have not seen it around in many many years.