MV-1B resetting in attract mode help!

so ive been using this mobo for around two weeks now. every once and a while id have a little more trouble getting a game to start vs my 2slot, but nothing out of the ordinary really.

now today i go to play (mind you i hadnt touched a thing and it was fine last night) and the neogeo bootup screen plays, then it goes to a garbled screen (in the case of kof97 a grey screen with some garble on the sides, world heroes is black with garbled credit/level text and the music does start to play, and samsho is doing the same as world heroes.)

then it reboots again, and loops infinitely.

if you put a coin in, the games play perfect. no glitches, no resetting, nothin.

i adjusted the voltage on my psu, first down which made it worse, then up. around 5.5ish it did boot to the attract mode once, but not again.

any ideas?

5.5v will kill chips.

TTL and TTL compatible logic runs from 4.75 to 5.25 volts.

Clean the slots and the cartridge edge connectors.

RJ

i was measuring at the psu, so hopefully at the mvs it wasnt too high.. anyway it works fine once you pop a coin in.

it seems odd that it would be a dirty connector problem if the games dont exhibit any other issues, and its consistent with every game.

If the dirty cart connectors are on the pins where the program ROMs connect up then it won't be able to read the program correctly... If that happens it won't run right at all.

I had that resetting on an AES with dirty carts, so it could be it. Happened with a Yaton Last Blade cart until about the 30th time I cleaned it.

not sonic said:

i was measuring at the psu

Click to expand...

Always measure at the mvs/jamma edge connect as there will be drop in the harness.
I would recommed typically 5.1 volts

bump.

its still doing the same thing with kof97, world heroes, kabuki klash, and samsho.

however, kof98, kof2k3, and metal slug x boot perfect.

the difference is the latter three boot the game right away and dont show the bios. and when it loops it shows the bios fine and goes to the game.


with any of the others if you pop a coin in and then use it up, itll go to attract mode as normal. but then when it does the bios animation, it wont go back to the game. (unless of course you pop a coin in.)

bump.

sometimes itll go to the attract, but only once. tried it in different cabs, same thing.

still games that dont show the bios on start up will loop fine.

once when i turned it on i got a backup ram error.


theres also a small wire running from one of the ram chips i believe to one of the bigger chips (cpu?) is this supposed to be there?

also baseball stars froze while playing.

id really like some help with this.

Arent certain MV-1B boards limited as far as the bios since some were for dedicated IM cabs? Maybe a bios upgrade may fix it?

how long is the test supposed to take?

i did it but nothing was happening and i had to go to bed.

but right now the board seems to be working fine.

If the Backup RAM is bad it will tell you during the test. It never ends.

If the board is working fine now (and not failing during the splash screen) then maybe the Backup RAM was corrupt.

When that happens you need to leave the system on for 24 to 48 hours and let the backup battery charge. If it's not holding a charge or is leaking it must be replaced quickly to avoid board damage.

RJ

What bios does it have in it ? It sounds like its not swapping between the cart and bios tiles correctly.

Raz

i can get the exact bios revision when i get home, but i know the copyright is 1995, its newer than the one in my 2 slot or my mv-1f. its got the snk logo at the bottom and all.