Problem with motherboard mvs1f

[konrad]

Do you have an EPROM reader? If not, not really. You could use the reader to compare the actual contents of your chip to the known correct values.

It would be easiest to just swap one from another board, but you obviously may not have access to an extra.

Ultimately, if your chip verifies as good in a reader/you swap a working one from another board onto yours and see no change, you probably have an addressing/data line problem that needs to be figured out. How to do that is really beyond the scope of explaining here, unfortunately. If you have a logic probe, you can start to maybe narrow it down.

Thanks for listen.

 

[konrad]

I have two motherboards measure it mvf1, one gives the z80 error and the other has the Lo chip, which zooms badly but the sound works, which of the two would you repair?

 

[HeavyMachineGoob]

The one with the L0 ROM issue could be simpler to repair given a lack of tools.

Go to https://m.coolrom.com.au/roms/mame/8917/Neo-Geo.php and download that neogeo.zip file, take out the 000-lo.lo file

Take that file and go to buyicnow, buy a 27C1000 chip with 1x EPROM burning service, email them the 000-lo.lo file from earlier.

While you're at it, may as well burn yourself a diagnostic BIOS too. Buy a 27C1024 (sp1.ROM) and a 27C010 (m1.ROM) from buyicnow and get the diag ROMs from here:

Neo Diagnostics homepage

In a dire pinch, you can take any MVS game from about 1992 or later, desolder the M1 ROM and temporarily solder in the diagnostic M1 ROM from the above link and use that to diagnose a Z80 error.

For actually repairing the L0 ROM issue, you use the burned replacement to see if that fixes the problem. If the problem remains, then you look for board damage and corrosion.

 

[konrad]

The one with the L0 ROM issue could be simpler to repair given a lack of tools.

Go to https://m.coolrom.com.au/roms/mame/8917/Neo-Geo.php and download that neogeo.zip file, take out the 000-lo.lo file

Take that file and go to buyicnow, buy a 27C1000 chip with 1x EPROM burning service, email them the 000-lo.lo file from earlier.

While you're at it, may as well burn yourself a diagnostic BIOS too. Buy a 27C1024 (sp1.ROM) and a 27C010 (m1.ROM) from buyicnow and get the diag ROMs from here:

Neo Diagnostics homepage

In a dire pinch, you can take any MVS game from about 1992 or later, desolder the M1 ROM and temporarily solder in the diagnostic M1 ROM from the above link and use that to diagnose a Z80 error.

For actually repairing the L0 ROM issue, you use the burned replacement to see if that fixes the problem. If the problem remains, then you look for board damage and corrosion.

I have a friend who has an electronics store that repairs televisions and videos and music equipment and I am going to tell him to replace the Lo chip on the motherboard that has bad sound and place it on the board where the Lo chip fails. Thanks for listen.

 

[HeavyMachineGoob]

I have a friend who has an electronics store that repairs televisions and videos and music equipment and I am going to tell him to replace the Lo chip on the motherboard that has bad sound and place it on the board where the Lo chip fails. Thanks for listen.

No no, the L0 ROM chip replacement should be for your other MV-1F that has the sprite scaling problem.

The board with the Z80 error, it most definitely isn't the L0 ROM, totally unrelated. Again, Z80 error means a problem between the Z80, the 6116 2K SRAM, the SM1 ROM and the YM2610.

 

[konrad]

I'm going to repair the one that has the sprite scaling problem because the sound and image work, then when the characters move away in the samurai shodown the scaling appears out of order.

 

[konrad]

Solved thanks.

 

[maki]

@konrad what was the problem, how did you fix it?

 

[konrad]

@konrad what was the problem, how did you fix it?

Replacing the chip.

 

[Neo Alec]

That's awesome! It was a bizarre problem. I'm glad replacing the L0 ROM chip worked. @HeavyMachineGoob you're a hero.

 

[konrad]

¡Eso es genial! Fue un problema extraño. Me alegro de que haya funcionado el reemplazo del chip ROM L0. @HeavyMachineGoob eres un héroe.

thanks for listen.

 

[konrad]

Same problem again, I got another board, this one I kept for spare parts.