MV1C issue: need help

[Fulkelmis]

Hi folks,

my 1st post to this forum. I have already done a consolized MVS with a MV1C mobo + unibios + stereo sound + VGA out + scan line. Works perfect. 17 games shockboxed + 2 arcade sticks + 2 neogeo CD pads later, I am doing a 2nd one, received 6 months ago, tested ok (video at least).
I have started today consolizing the 2nd: (3,4,C,D) on +5v, (1,2,14,27,28,A,B,E,F) on ground. 12 for red, 13 for blue, N green, P sync. Tested with my vga card: nothing. Tried the stereo sound hack: no sound (and no more video). Inverted the fuse with my working one, nothing more.
Any idea?

Then, I have played a little KOF98 with the consolized one, enclosure opened. No pb. After closing the enclosure (which pressure a little bit on the neomasta + bios), nothing special. A couple of hours later, I wanted to play a little Metal Slug. Then I have at start a "porridge of pixels" (bleu, green, red, ...), even when I have no game in it. After opening the enclosure, I have seen that the neobios masta seems a little bit unplugged. After set in place, still a "porridge of pixels". Exchanged with an older unibios, double checked mobo + voltage, nothing more.

What a f*****g weekend :-(

Can it be related to the bios installation? Any other ideas?

Thx in advance.

 

[Xian Xi]

Make sure the NBM is snapped onto the CPU very good and sitting flat. I usually add a bit of hot glue once I verify it works correctly. Its mostly for shipping precautions.

 

[Fulkelmis]

Thx. I have found the problem for the consolized mono: one of the wire connected to the NBM was disconnected.... but only visible with a magnifying glass. Everything OK by now after soldering it again.

For the 2nd one, I finally get a video output (how? I don't know). But impossible to get sound by taping the sound directly from the chip. Any smart idea?
Thx

 

[Xian Xi]

Was the 2nd board's sound working before? The MV1C has a chip called the YSA2 that fails often but usually on the controller input side. You might have a bad 9480, that is the small 8 pin DAC IC that you pull the audio from.

 

[Fulkelmis]

Never tried the sound on that mobo. Plus, on my other MV1C, I have never connected the +12V, so I can't test it this way.
if it is the case, any way to solve it? By replacing the 9480?
Thx.