Various SNES hardware failure, burn-in test results inside

[People?]

Hello! I have three different SNES consoles with various hardware problems.

The first SNES is mostly working fine. A few games are crashing. When I used the SNES Burn-in cartridge 1.03, and ran the burn-in test, it said: HV Timer - FAIL. I do not know what this is, do you?

The second SNES is not working well at all. None of the games I have tried work properly, all have graphic problems and crash (not immediately). When I ran the test, it stopped at: VRAM - LOW - FAIL

The third SNES lights up, but gives no sign of life on the TV. No picture, or even a flicker upon startup. When I checked on the inside, I noticed that the CIC chip was missing, and the fuse had been replaced with a piece of wire. Could the deadness of the system be a result it not wanting to work without the CIC? Could it be possible to bypass it somehow?

I suppose the VRAM on the second SNES is faulty, and assuming it is not on the third, would it be possible to desolder the VRAM chip (assuming it is a seperate chip) on it, and putting it in the second SNES for full working glory?

Any insight on this would be highly appreciated. Thank you for your time, regardless. 

[l_oliveira]

1st- HV-Timer is in PPU-1  (Horiozontal/Vertical timer, used by some games to make separation bars like gauges, panels, splitscreens etc... Also ulsed as synchronization aid by gun games to calculate the aim of the user when the player press the trigger and is aiming to the screen...)


2nd - VRAM is a pair of 62256 (32KBYTE) Static Random Access Memory (SRAM) chips close to the PPU 1 and 2 chips.  Extremely unlikely that the SRAM chip is broken it's easier that the copper on one of the pins of either chip got interrupted by corrosion.


3rd - Without the CIC chip RESET will be held LOW and the system won't start.

Hopefully that helps you a bit.

[KeepGood]

With the removed CIC.  Patch a wire from where pin 10 was on U8 (the CIC chip) to pin 4 of  U10 (U10 is under the heatsink).  That will allow it to run without the cic chip being on the board.

[l_oliveira]

You still need a pulse of the reset pin to properly kick off the system into running state.

Just pulling the RESET to +5v is not a real solution.