MVS1F Boot Error

[Itstoohard]

Hello There everyone,
Would like to  pick someones clever brain on this-
Have the above 1 slot MVS  starts booting up and just before you would expect the x hatch screen to appear all I get is a blank cyan screen with a few blocks of garbage. same with or with out cartridge fitted.
I have checked  the xtal. Have done the basics first physical inspection track check etc. What Rams should I look at first (no not the sheep..)
The closest thing I have to a slot machine is an Xbox because all I do is pump money in it for my son. lol

With Thanks from the Down Under

Aaron..

[channelmaniac]

This is in order of most to least likely:

First thing to check for would be a leaking battery. If it's leaking then repair the traces around it as that controls signals to the backup RAM.

Next would be to check for proper /CE /OE and R/W signals on the backup RAM.

After that would be to look for a bad BIOS chip, bad Backup RAM, or bad Work RAM.

RJ

[Itstoohard]

Thankyou for your advice.
It turned out to be a bad Ram (one of the four rams near the Neo C1 custom chip) had an ADDR input held low on A5.
I will share anything else I come across.
Aaron.

[channelmaniac]

Cool, thanks for the update!