Chip marked "112 732" on PU-18 side B

Post by **magolpiu** » July 27th, 2024, 7:19 am

Hey all,

I bought a PSX from Ebay and someone had done a bad job putting a 4-wire modchip and seems to have lifted a pad next to a 16 pins chip with a "112 732" label.

From what I understand this was connected to the "Gate" wire of the modchip (presumably to pull it low?), before the pad broke and lifted (it's still attached to a wire of the modchip).

I am trying to restore the console to its original state (no modchip) and I would love to find an alternate point to connect this chip's leg.

Any information, help, pointers would be appreciated (what is the chip marked "112 732" ? What is this pin (pin 10?). Where does it normally connect to (trying to find an alternative point from the pad that was lifted).

Thanks for any help!

lifted_pad.JPG

lifted_pad_2.JPG

Post by **magolpiu** » July 27th, 2024, 10:53 am

Well, after close inspection it seems like this pad is not connected to anything besides the pin of the mysterious IC. The pin of the IC must be connected somewhere else through a trace that goes underneath the IC. So hopefully there is nothing for me to do here, and this was just an unused pad designed for testing like the ones above and below.

Post by **nocash** » July 27th, 2024, 11:42 pm

Yes, test points aren't needed for anything.

For what that chip is, when searching for "16pin" in psxspx, it seems to match this:

Code: Select all

  GATE is IC706.Pin7/10   (16pin "118" (uPC5023GR-118)      ;PU-18 .. PU-20

But there it's called "118", and the barely visible part number on your photo looks like "|...18, (N) ..." or so.
I would almst rule out that the chip is marked "112 732".

Post by **magolpiu** » July 28th, 2024, 1:40 am

Thank you so much for your help and the pointer, that will help me understand more.
You are right, it's 118 732, not 112 732, sorry for the mistake.

Post by **TriMesh** » July 28th, 2024, 7:30 pm

That pin only connects to the pad that's broken off - but there are multiple other points you can use for the gate signal. The easiest one is the testpoint below the chip - if you go down from the loop in the red wire in your photo past the chip and the SMT resistor and cap it's the testpoint just there.