AJZ IC on the back of the board causing no boot..Booting once removed

So I purchased a switch from eBay that had water damage … I know the charging IC is bad and I have a new TI one on the way. I was able to get it to boot a few times after removing it and was able to play some games but about 30 mins later I couldn’t get it to turn back on. After some some poking around I decided to remove the IC that had the worst of the water damage and now it boots every time no issues. I have not fully put it together since I’m waiting on the replacement backlight IC so I really haven’t tested it completely but it does boot and I can dock it. So my question is, does anyone known what the area is for and is it absolutely needed? Also, when I was able to get it to boot in the beginning before it stopped, I had no image what’s so ever, now I can see an image with a flashlight… it’s so weird . Could really use some expert advice on if this is absolutely needed and if there is a replacement IC I can order… I can’t find anything for +AJZ … This IC is on the back of the board and it is a HAD-CPU-01

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I cant for the life of me figure out how to upload a photo so I can show what I am talking about.

I just recently reveresed the ALJ IC on Mariko and it’s a Maxim part, so AJZ is almost certainly Maxim too. Your AJZ will be a buck/boost (step up/step down) converter of some description and you should be easily be able to narrow it down by pin count, package dimesnsions, and type (WLP) there’s only about 8 parts on mouser fitting this description.

In the case of the ALJ IC on Mariko it’s purpose appears to be similar to that of the DC0 IC on original rev switches albeit with quite so major differences, but regardless it provides a VIN for a pin on the M92 IC… In your case with the AJZ IC I’m not so sure as I haven’t buzzed it out

Bit confused by this as you said you pulled the backlight driver IC so this would be normal… unless I’ve missed something?

The board was purchased from eBay with little water damage and it was contained to a very small section of the board. I pulled what I am assuming is the backlight driver (U7N 9 pin BGA) and have ordered what I think is a TI replacement (TPS61163AYFFR). After removing this IC it did boot and I was able to use it for a short time with only cleaning with IPA the +AJZ 917 IC but it quit shortly afterwards. Since this was the only other IC that had corrosion and was the worst of anything I decided to remove this one as well and now it boots every time. I haven’t put the entire Switch together so I don’t know if everything works but it does now boot and will dock. Another thing it’s doing that it wasn’t before is showing a display on the LCD that you can see with a flashlight. So now I have some questions …

1: is this IC (+AJZ 917) needed or important
2: what does it do
3: is there a replacement I can order
The IC is stamped +AJZ 917 and is a 9 pin BGA

I have photos but can seem to find a way to add them to the topic … thank you for any insight you can provide .

I know the IC your referring to, but as I said, this is all stuff you can pretty easily find out yourself buzzing out the IC yourself and identifying… there wouldn’t be a regulator populated on the board if it wasn’t important.

As I said it’s a step up/down regulator

Yeah it’s on mouser, it’s one of the previously mentioned 8 possible parts.

Unfortunately I haven’t went to the effort to identify it myself yet as I’ve never had issues with it, sorry.

Just add, you shouldn’t be powering the board with noted corrosion or damage until you can verify fault conditions have been resolved with your meter, I understand the temptation to power the console on, but from my experience it will lead to tears :wink: