[FIXED] MK2 issue

[anunaki]

I have an issue with my MK2 cab, hopefully someone can help me out with it.

When I start my system, sometimes 2 roms are bad (red), the U10 and U11. The game plays normally, untill I get to Kintaro. The image gets all messed up.

When this 1st happened, I've adjusted my power supply unit and the issue was gone. After moving my cab to work on the coin input (it runs on good old Dutch guilders, how cool is that ) and putting it back in place, the issue returned

Can it be my PSU is getting bad? I'm a little scared to keep adjusting the voltage in the blind., but I'm not sure how to check the voltage on the PSU

Please help me out here

Greetz, Patrick

[Robinholland]

buy a multimeter

[anunaki]

I had one, measured the +5V output on the PSU, no issue there. The adjustment thing is a little crappy, but it still works.

So now I've got two ROM chips that fail. The EPROMs are on the Memory Expansion board.

What´s the next thing I can do?

[anunaki]

I watched a video on youtube of a guy who had a similar problem with a MK3 board. he had to put the +5V down to fix it.

measured the +5V it again on the PSU,  it seems to be more than 5V at the lowest I can put it with the knob. I have an analog multimeter with a small scall, so I'm not sure how much over 5V it is. I get myself a digital one this weekend.

Does anyone know the usual range of the swithcing PSU adjustable +5V?

[anunaki]

Yeah!!!! It't working fine again

I got myself a digital multimeter, nothing wrong with my PSU (lowest is around 4,75V).

I reseated the Memory expansion board, and it all works fine again

Will be putting some pictures online tomorrow or so, cause I'm gonna fix her up a little

[Belike]

Nice to hear that it was an easy fix.

[Robinholland]

4,75 volt is very low for a stabiel game
Try 5.00 volt if you got problems again