Need help with bios mod

T

therealmogwai

n00b
Joined
Nov 27, 2006
Posts
10
i need help with this bios mod!
On this website it says to remove the old bios chip yet with the instructions that came with the chip it tells you to stack the chips and connect them together...


can anyone help?
thnx
 
Xian Xi

Xian Xi

JammaNationX,
15 Year Member
Joined
Dec 1, 2005
Posts
27,751
If you have the socketed bios just remove the old one and put the new in. If you have a soldered bios you can either desolder the old one and put the new in or you can do a piggyback like you said.

If you have an MV1C MVS board you will need to desolder the bios and rewire the new bios. I believe everything is on the unibios website.
 
T

therealmogwai

n00b
Joined
Nov 27, 2006
Posts
10
thanks for your help....its an AES system...no socket

serial is 19296

pretty old i guess
i can't believe how hard it is to remove a chip!!! I keep on melting the sodder but because of so many points of contact cannot remove the chip!...ARG so fustrating
 
Xian Xi

Xian Xi

JammaNationX,
15 Year Member
Joined
Dec 1, 2005
Posts
27,751
therealmogwai said:
thanks for your help....its an AES system...no socket

serial is 19296

pretty old i guess
i can't believe how hard it is to remove a chip!!! I keep on melting the sodder but because of so many points of contact cannot remove the chip!...ARG so fustrating
Click to expand...

If you want to desolder the old chip the easiest way for a novice solderer is to snip the chip off and then remove the legs from the solder by heating them up.

But I would suggest doing to piggyback.

There are some people here that can install it for you for a fee.

Also make sure you solder in a socket and not the chip. This way you can upgrade the chip later with just pulling the chip out.
 
norton9478

norton9478

So Many Posts
No Time
For Games.
20 Year Member
Joined
Oct 30, 2003
Posts
34,074
I have had much more troule desoldering the AES Bios than other chips on other TV's
 
A

Adamaki

Haomaru's Blade Shiner
Joined
Oct 7, 2004
Posts
678
I reckon unless you've got a really good solder station it's virtually impossible to remove the old bios without snipping the legs off first. Some of those pins are really stubborn, especially the ground pins. I ended up using nearly a whole roll of solder wick trying to get the solder out of the last few holes!

Why not just piggyback a socket? That way you can still upgrade your bios in future, but don't have to bother desoldering the old chip.
 
ttooddddyy

ttooddddyy

PNG FTW,
Joined
Nov 29, 2001
Posts
8,335
Adamaki said:
Why not just piggyback a socket? That way you can still upgrade your bios in future, but don't have to bother desoldering the old chip.
Click to expand...

Good advice ;)
 
P

poizon74

n00b
Joined
Feb 23, 2007
Posts
8
problems

Hey guys, the forum wouldnt let me post a new thread (not sure why) but it seems to let me post a response so hopfully someone will read this.

I just got a debug bios chip (not the cooler unibios, but thats fine with me) and I installed it. I have good sodering skills and a multimeter, so i checked all connections and they look fine. But i cant get the system to boot up, I just get this weird jumbled colors crap on my screen.

I read up on this a bit and found that the whole cutting pin 2 is about turning on and off bios chips. With my multimeter i then measured the voltage accross pin 2 on both chips while the system was breifly on. Both read +5V, so i figured in there lies the problem since you need pin 2 to go to ground apparently to turn on any one chip.

After poking around i found some pecular stuff, maybe someone can inlighten me to the pinout of the bios chip.

Looks like pin 20 (supposedly where you can get ground from) isn't grounded, but My pins 11 and 30 are grounded. I tried setting one chips pin 2 to one of these pins, I even tried connected pin2 to the far ground (near one of the side screws on the edge of the board) to make sure it was grounded, bu still nothing.

I'm wondering if I could have broken a trace while cutting my original pin 2. There is a tiny trace next to this pin that looks slightly scratched. But it honestly doesnt look broken.

I'm very suprised that I can get this chip to work. If anyone knows the pin out of an AES bios chip or has any suggestions please let me know, at this point I'm conpletely stuck!:conf:
 
MKL

MKL

Basara's Blade Keeper
20 Year Member
Joined
Mar 8, 2002
Posts
3,686
it works like this: pin 2 of stock bios to 5v (after it's no longer connected to ground) and pin 2 of new bios (unibios, debug, whatever) to ground (the two pins shouldn't be touching each other of course).
 
P

poizon74

n00b
Joined
Feb 23, 2007
Posts
8
yes your right, pin 2 turns each bios chip on or off, ground is on and 5v is off. i've connected the pins properly and still my system won't work. I've now even tried completly removing the debug chip (just leaving the old chip connected and its pin 2 to ground), and my system still won't work. I'm rather upset about it, I followed the instructions to the t and now my system appears broken.

All I can think is that I must have damaged a trace while disconnecting pin 2 of the original bios, though the board looks undamaged.

Not sure what I can do at this point, the bios installation process has left my AES rendered useless!
 
Xian Xi

Xian Xi

JammaNationX,
15 Year Member
Joined
Dec 1, 2005
Posts
27,751
poizon74 said:
yes your right, pin 2 turns each bios chip on or off, ground is on and 5v is off. i've connected the pins properly and still my system won't work. I've now even tried completly removing the debug chip (just leaving the old chip connected and its pin 2 to ground), and my system still won't work. I'm rather upset about it, I followed the instructions to the t and now my system appears broken.

All I can think is that I must have damaged a trace while disconnecting pin 2 of the original bios, though the board looks undamaged.

Not sure what I can do at this point, the bios installation process has left my AES rendered useless!
Click to expand...

How did you disconnect pin 2, did you snip it or try to cut it because there is 2 traces that run right by pin 2. Also what wattage were you using to solder everything, if it was too high or left on for a long duration you could have fried something.
 
Razoola

Razoola

Divine Hand of the UniBIOS,
Staff member
20 Year Member
Joined
Nov 12, 2002
Posts
4,662
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).
 
Kpj

Kpj

Larfleeze, Wielder of the Orange Light. , formerly
Joined
Sep 7, 2001
Posts
1,812
If you'd like, you can send the unit to me for the upgrade/install.

PM/email me if interested.
 
MKL

MKL

Basara's Blade Keeper
20 Year Member
Joined
Mar 8, 2002
Posts
3,686
poizon74 said:
All I can think is that I must have damaged a trace while disconnecting pin 2 of the original bios, though the board looks undamaged.
Click to expand...

I assume you have a later motherboard revision with the bios located to the right of the cart slot. If that's the case there are 3 traces between pin 2 and 3 that you may want to check:

http://img.photobucket.com/albums/v65/nassivera/stuff/Immagine1.jpg

they aren't bios related, their path is:

68000-12 (pin 52)--------NEO-E0 (pin 54) red
68000-12 (pin 51)--------NEO-E0 (pin 53) blue
NEO-1C (pin 76)----------NEO-E0 (pin 61) black

check continuity and if one or more appear to be unconnected solder a small piece of wire-wrapping wire between the vias shown in the pic.

If this doesn't help try to post hi-res pics of the bios and its surroundings.
 
P

poizon74

n00b
Joined
Feb 23, 2007
Posts
8
wow, thanks everyone for the great help!

ok now looking at that pinout (thanks razoola) i'm fairly convienced that my bios chip is still working fine. Looking over my board again i think i may have damaged those traces that run next to pin 2.

MKL thanks for the pic of the board layout in that region, i tested the connections from the ends of the traces not covered by the chip and they are connected as you have shown to another nearby chip. My problem is i don't want to completely remove the old bios chip, but how else can i test the points under it? do you know any locations on the board where i could make a jump connection from the exposed trace ends to circumvent the potential broken connection to the points under the chip?

thanks again to everyone for the speedy replies and all the awesome help, i'm feeling much more confident now that i can repair the problem!
 
P

poizon74

n00b
Joined
Feb 23, 2007
Posts
8
I actually have another question now looking over the pinout for the bios chip again. to install a new pios chip by piggybacking your instructed to connect pin 2 or the old chip to pin 40 which is 5v (thus turning it off), but then your told to connect pin 2 of the new chip to pin 20? pin 20 is not ground, could the instructions mean connect to pin 30? (pin 30 is ground).

i found this kind of odd, but many descriptions of the piggyback method say connect pin 2 of the new chip to pin 20, and reason for this? couldn't I simply have pin 2 jump to ground?

thanks again for the help, i'll keep working on my problem.
 
MKL

MKL

Basara's Blade Keeper
20 Year Member
Joined
Mar 8, 2002
Posts
3,686
poizon74 said:
MKL thanks for the pic of the board layout in that region, i tested the connections from the ends of the traces not covered by the chip and they are connected as you have shown to another nearby chip. My problem is i don't want to completely remove the old bios chip, but how else can i test the points under it? do you know any locations on the board where i could make a jump connection from the exposed trace ends to circumvent the potential broken connection to the points under the chip?
Click to expand...

You don't have to remove the old bios: the vias under the chip are accessible from solder side if you flip the board over. But did you check continuity across the chips I mentioned above (from the 68k to the NEO-E0, etc)? Because if you have continuity there, then you also have it in the segments under the bios of course.

As for ground and 5v, I suggest to take them from the capacitor near the bios instead of the bios itself (the less you tinker with the bios the better):

http://img.photobucket.com/albums/v65/nassivera/Immagine2.jpg

In any case bios pin 20 is not ground, where did you read that?
 
P

poizon74

n00b
Joined
Feb 23, 2007
Posts
8
MKL, I tried the connections you mentioned from the NEO-EO to the 68000-12 and the NEO-C1, none of them worked! If these traces are connected through the vias you mention then I have probably damaged them. Connecting the NEO-EO and 68000-12 are easy, but connecting to the NEO-C1 is harder with its smaller pins, I don't think I can do it right with the tools i have, is there anywhere else on the board where i could pull this signal from?

Also i found on neo-geo.com, as well as the instructions that came with my debug chip that in the piggypack method you would put pin 2 of the chip you want disabled to pin 40 (makes sense), and then put pin 2 of the chip you want enabled to pin 20 (doesn't make sense to me). I noticed that the same instruction was given from the universe bios homepage on how to install their bios chip as well. Thanks for the pic of the capacitor, both of the connections you show look totaly correct and i will jump to those locations to enable/disable the bios once I get these broken traces fixed.

Thanks again everyone, especially MKL. If this community wasnt here to lend me a hand I would really be in trouble!
 
P

poizon74

n00b
Joined
Feb 23, 2007
Posts
8
ok, ive managed to make the patch connections you mentioned MKL (i jumped to certain via spots instead of pins to make certain connections easier).

now when i turn on the system i get the start up screen, but it looks weird (has little arrows all over the logo) and no game will boot. I'm going to retest all of my connections, btu i think im on the right track.

also, can it hard my AES games to test them on the system? i just want to make sure, i wouldnt think so, but AES games are expensive and i don't want ot put my cartridges at risk.

thanks again
 
MKL

MKL

Basara's Blade Keeper
20 Year Member
Joined
Mar 8, 2002
Posts
3,686
It would probably be easier to tell what's wrong with it if you posted pics of the board showing the bios area and the repairs you did.
 
S

sonofx51

If you're even THINKING about TRADING with this us
Joined
Sep 8, 2000
Posts
436
Sorry to dig up an old thread but I can't make a new one. I have a NEO AES3-5 with a botched bios removal. I fixed the traces and added a socket but I still get garbage on the screen and no game will boot up. I have checked all the points according to MKL pinout and it all seems to check out just fine even the 3 extra points mentioned. Is there anything else I should try? I'm trying to use a unibios 3.0, eprom tested on MVS and works fine.
 
S

sonofx51

If you're even THINKING about TRADING with this us
Joined
Sep 8, 2000
Posts
436
I just noticed the the NEO-C1 had pins 29 and 30 touching, is that normal? I tried separating them and still nothing.
 
You must log in or register to reply here.
Top