Namco Super System 22 Time Crisis 1 - SUBCPU Start Wait NG

[MagicianLord77]

Hi, I've got an untested Time Crisis 1 cabinet that is having a "SUBCPU START WAIT NG" error at boot up, is stuck there, also test switch / service button don't do anything:

Yes, I'll be replacing the mirror
PSU is providing good 5.2v at the board. I've inspected and reconnected the boards from the cage. Only repair I found was that the C402 customs of the DSP board were reflowed.
I couldn't find any info about this "subcpu", most mentions of it are related to Time Crisis 2 boards. Is it really located at the DSP board? because DSP START WAIT is "OK"

I found a person with the same issue from 2014 but no replies https://forum.arcadeotaku.com/viewtopic.php?p=408082

Anybody knows how to troubleshoot this, what does the error mean? thanks

 

[Franco23444]

It’s probably the gun board that’s located inside the chassis. Check if it’s seated properly or doesn’t have any broken traces due to leaking capacitors

 

[Ape Cosplay]

Also lower the screen pot, retrace lines are visible.

 

[MagicianLord77]

Also lower the screen pot, retrace lines are visible.

Yup noticed that, it was just the very first power on of the machine (since who knows how many years), I plan to replace it anyways because it's a 26in and should be 29in.

It’s probably the gun board that’s located inside the chassis. Check if it’s seated properly or doesn’t have any broken traces due to leaking capacitors

There is its Gun Point PCB, seems it had 4F and 3F replaced at some point (solder flux), the rest looks fine, no signs of corrosion.
Do you know if the Sub CPU error I'm having happens if the Gun Point board is disconnected? because I turned it on without it just to see and the error remains the same.

Also tried without connecting the Gun Drive PCB (the small external one), same. With or without the 24v psu.

LEDs remain like this after the boot stops on the "initialize incompleted" message, the ones from CPU board are static and the one from the DSP board toggles between that one and the one to its side: