New Net City partially powers down

[Mageta the Lion]

Hi,
i got problems with a New Net City which seems to partially power down after a short/medium while.

With the Taito Type x2 Multi:
I either get a "No I/O Error" right from the start or i can play 30 - 45min and than get a white screen with an "no i/o" error (rarely the game keeps running and all btns stop working).
The type x2 is plugged into the socket on the back of the NNC (it doesn't use the psu of the NNC)

With the Atomiswave (Jamma to JVs Adapter):
The game starts up and after a couple of Minutes i get a black screen and all Fans stop, followed by the no Picture/Sync screen of the NNC. The "Jamma to JVS" adapter is plugged into the NNC psu.

I use a 800w Step down convert to run the NNC.
The NNC was bought from a friend who used it for a couple of hours the day before the transport so i assume the damage is transport related.
The transport wasn't as "clean" as i had hoped, the car was missing the famous couple of centimeters so the NNC didn't fit right and had to ride with its bare Ass outside of the car through the rain. So something important might have gotten wet. (But it has been weeks since then)

tl;dr: the PSU (probably) stops working after a short while but the tube keeps on running.

Any hints what to check? Right now I'm considering switching the psu of the NNC with a PC ATX Psu but I'm not sure if i can rule out the other components (Sega I/O and [what's the board to the right of the psu, chassis?])
Any way of making sure the psu is at fault without rewiring everything?

 

[Mageta the Lion]

No Old Sega Guru around who can smell the solution to my issue around the globe from my description ?


But seriously any info missing? Nobody has any wild guesses or had similar problems in the past?

 

[notsonic]

Does the power supply shut off? There's a power light next to the voltage adjust.
What are the voltage readings? If possible, try to catch the voltage readings during the failure too.

When you say fans, do you mean the Atomiswave's fan or the rear cabinet fan?

The board next to the PSU is the sound amp. The IO is under the control panel and behind the front monitor cover.

It does seem like there's something wrong with the PSU.

 

[Mageta the Lion]

All Fans stop working, the one in the Atomiswave and the ones of the NNC (you can hear that all Fans stop working).
Don't have a voltmeter so no way of checking the voltage (i know capital sin). But the Jamma to JVS Adapter didn't work with the MVS and a Puyo Puyo Bootleg so the Voltage might be out of whack (not comfortable putting in a more "expensive" Board).
Will check if the power led on the psu is on this weekend