Problem with newly acquired MVS-1: Green Screen on Boot

Hi all. I'm having a problem with a newly acquired MVS-1. I have two MVS carts that I thoroughly cleaned. They are Metal Slug and Magical Drop 3. I also cleaned the JAMMA connection on the MVS board, and all metal contacts on my harness and cartridge slot.

I without fail get a green screen on boot up. I have owned four Neo Geos in the past, ranging from AES to MVS, and know that sometimes you need to wiggle the cart to a certain spot for the game to play. I've done that to no avail.

Please see attached pictures. Any help would be appreciated. Please note my screen is vertical since I had shmups in there. Was planning on rotating it.

Thank you.

Does it boot to crosshatch without a cart?

It's also hard to tell from your pictures but check around your battery and make sure it hasn't started to leak.

It won't boot to crosshatch without a cart. This is a calendar error.

Check 32khz crystal output and check that the calendar IC its connected to is functioning correctly.

Search for "calendar error"...I think the likely cause is a bad crystal IIRC.

i have always gotten that ugly screen on boot-up i thought that was normal or do you not make it past that screen?

Yes, that screen is normal on startup but with a calendar error it will stay stuck on that screen and go no further.

oh ok good i was thinkin all mine have been broken

lol hey you never know maybe it was a common problem

Most older arcade systems display garbage when they're booting up. Never quite known why to be honest.

The garbage being displayed is the system going through self tests and hardware initialization. The RAM chips power up in an unknown state, in other words, full of garbage.

That garbage is seen when the system is first powered up then it goes through the initialization steps which result in the green screen and other commonly seen things. However, if the initialization fails then the system will get stuck or be reset by the watchdog timer.

Stuck on green is a calendar error, but before you blame the crystal next to the D4990 clock chip, you need to check that power is getting to the chip.

Pin 14 on it should be around 3v even with the power off. With power on, it should be at +5v. If not, you'll get the stuck on green problem.

If power is there, then check to make sure the crystal is working. An oscilloscope or logic probe will help here. If it's not, replace it.

If the crystal is working and the chip has power then you need to check for corroded or scratched traces. I just fixed a 2 slot board with a calendar error that had 9 gouged traces on the bottom of the board. The clock/calendar chip was OK and the problem was that the system couldn't access it because of the trace damage.

RJ

If the 5 volt rail is lowish it can cause this

I've had an MV-1FZ and MV-1A that show that at boot-up but then ran the game. My MV-2F never does this? Wierd.

doctor_shred said:

I've had an MV-1FZ and MV-1A that show that at boot-up but then ran the game. My MV-2F never does this? Wierd.

Click to expand...

That's interesting as I only get the green boot with my 1 slots as well. Never seen one from the 20+ 2 slots I've owned.

Wtf?

I've had 4 and 6 slotters that have done this, so it must only be the 2 slot that doesn't. How weird.

My 4 slot does this. Sometimes the green screen stays for up to 5 minutes before it continues to boot and sometimes it just stays green. I have the calender error come up once and also a z80 error come up once. Never seen neither again though.

HOLY thread brought back from the dead, Batman!