Neo Geo unibios install issue

Evan · Feb 20, 2018

I was trying to install a unibios using the piggyback method. When I was done the screen showed a garbled mess with one screen with different colors. There is also a slight popping sound when it is running. It seems to be resetting itself. If anyone could have a answer to this it would be appreciated.
https://drive.google.com/file/d/1tlKiS-OHP2OfG_pDIOvr6HmZmlPxiD7t/view?usp=drivesdk
https://drive.google.com/file/d/12tX37Bzl0FCHRF7873ojx8Ai7C2KJn_G/view?usp=drivesdk
https://drive.google.com/file/d/1_-LfjPmDLcsH8n2q_lT5CJyQMI31YNbD/view?usp=drivesdk

Heinz · Feb 21, 2018

You really should just get yourself an inexpensive solder pump and remove the old chip...

Morden · Feb 21, 2018

Evan said:
I was trying to install a unibios using the piggyback method.

Out with the BIOS, in with a socket. From this angle it's hard to see what exactly could be wrong, but seeing as the soldering is a bit messy, maybe there's a short?

Evan · Feb 21, 2018

Yeah, I ordered a socket and this weekend I should have time to remove the bios. After that I will instead just install a socket.

Razoola · Feb 21, 2018

The screens show something went wrong with the install. Below might help you if its still not working after socket install. Also, once you got the bios off the PCB take some photos so you understand where traces go that were under the bios.

Code:

This info is taken from NEO-AES3-6 and NEO-AES3-4 revision boards
and should be valid for all boards that have the bios to the right
of the cart slot. The older board NEO-AES which has the bios
above the cart slot is partly different.

* The 43256 (work RAM) closest to P1 joystick port

1----5V
2----GND
3----68000-12 (54), LSPC2 (21), NEO G0 (50)
4----68000-12 (55), LSPC2 (20), NEO G0 (49)
5----68000-12 (56), LSPC2 (19), NEO G0 (48)
6----68000-12 (57), LSPC2 (18), NEO G0 (47)
7----68000-12 (58), LSPC2 (16), NEO G0 (34)
8----68000-12 (59), LSPC2 (15), NEO G0 (33)
9----68000-12 (60), LSPC2 (14), NEO G0 (32)
10---68000-12 (61), LSPC2 (13), NEO G0 (31)
11---GND
12---68000-12 (62), LSPC2 (10), NEO G0 (18), 43256* (19)
13---68000-12 (63), LSPC2 (09), NEO G0 (17), 43256* (18)
14---68000-12 (64), LSPC2 (08), NEO D0 (03), 43256* (17)
15---68000-12 (01), LSPC2 (07), NEO D0 (02), 43256* (16)
16---68000-12 (02), LSPC2 (05), NEO D0 (01), 43256* (15)
17---68000-12 (03), LSPC2 (04), NEO D0 (64), 43256* (13)
18---68000-12 (04), LSPC2 (03), NEO D0 (63), 43256* (12)
19---68000-12 (05), LSPC2 (02), NEO D0 (62), 43256* (11)
20---NEO E0 (59)
21---68000-12 (29), NEO E0 (64), 43256 (10), HC259 (01)
22---68000-12 (30), NEO E0 (01), 43256 (09), HC259 (02)
23---68000-12 (31), NEO E0 (02), 43256 (08), HC259 (03)
24---68000-12 (32), NEO E0 (03), 43256 (07), HC259 (13)
25---68000-12 (33), NEO E0 (04), 43256 (06)
26---68000-12 (34), NEO E0 (15), 43256 (05)
27---68000-12 (35), NEO E0 (16), 43256 (04)
28---68000-12 (36), NEO E0 (17), 43256 (03)
29---68000-12 (37), NEO E0 (18), 43256 (25)
30---GND
31---68000-12 (38), NEO E0 (19), 43256 (24)
32---68000-12 (39), NEO E0 (20), 43256 (21)
33---68000-12 (40), NEO E0 (21), 43256 (23)
34---68000-12 (41), NEO E0 (31)
35---68000-12 (42), NEO E0 (32)
36---68000-12 (43), NEO E0 (33)
37---68000-12 (44), NEO E0 (34)
38---5V (N.C. on NEO-AES3-4)
39---5V
40---5V

Fault checking.


If for some reason the system no longer works then obiously some traces
have broken, check everything.

If the Bios is working but you get a memory card error on power up if a
memory card is inserted and a card protected error while trying to format
a memory card then one or more of the socket to NEO E0 traces have
broken (pin 20 to 37).

Evan · Feb 23, 2018

When I was desoldering the bios, I messed up and desoldering some of these small holes. I was wondering, does that mean anything and is there a picture to see how they should be?

MobiusStripTech · Feb 24, 2018

Those are vias. The ones that would have had solder in them will still have a bit of solder left. You wouldn't have been able to remove it all. Honestly though you could solder any of the open vias without concern.

Neo Geo unibios install issue

Evan

Fio's Quartermaster

Heinz

Parteizeit

Morden

Somewhere in Europe.,

Evan

Fio's Quartermaster

Razoola

Divine Hand of the UniBIOS,

Evan

Fio's Quartermaster

MobiusStripTech

Mr. Big's Thug