MV1C Unibios / NEOBiosMasta Install Troubleshooting

[dillingerradio]

Hey folks! I'm hoping one or more of you out there might be familiar with the NeoBiosMasta mod; or, more broadly, unibios installation on an MV-1C board.

I'm attempting to give it a go here, and I'm afraid I've run into a bit of a wall. I'll start at the beginning:

• I utilized a heat gun to safely and easily pull the surface-mounted BIOS from the board.
• I placed NeoBiosMasta shroud over the chip as instructed, and attempted to solder CE/OE to pads 10/12 respectively. A mistake ultimately resulted in the loss of the appropriate pads.
• I rerouted the wires according to information I found: CE -> GA1(7), and OE -> GA1(9)
• I tested continuity with original pads and checked for shorting. Continuity checks returned good, the reroute is technically successful; no shorts were detected.
• I removed the BIOS chip from the NeoBiosMasta and verified the data onboard was good, before replacing it and attempting a boot.

When booting (with or without cartridge), I am met with the garbled screen shown. It remains looking that way (while individual squares might animate with random patterns/flickers/etc.) for a while, and then occasionally will roll into flashing back and forth between colors before ultimately settling down (you can see what it looks like when it decides to start flashing here: https://imgur.com/a/PoK7tuG ).

I'm afraid that I lack the knowledge or experience necessary to move beyond this point (outside busting out some o-scope probes to start checking things; but, I'd be poking around in the dark, admittedly). As far as I can tell, this is a successful- if messy- install of the Unibios, and I'm unsure as to why I'm being met with this messy boot.

Any help or direction is greatly appreciated.

Cheers!

 

[pierpa86]

I installed a version of VMC that resembles it, as soon as I disabled the bios according to the NeoMasta procedure, disconnecting the 2 pins from the motherboard (without removing it completely) I had a similar problem.
Then I immediately reconnected the pins and my new bios overlapped.
Apparently it is not a good idea to remove or detach the pins on MV1C.