MV-2F Won't Save Bios Settings With New Battery

[GameLifter]

I recently got a new battery for my MV-2F board and it saves the date and time settings fine but when I make a change in the UniBios settings or soft dip settings they are lost after a power down. I originally had my friend do the battery mod with a CR 2025 battery but after it didn't work I bought a battery holder with a CR 2032 and installed it to see if it would make a difference. The results were the same. I tried running both the work RAM test via the dip switches and the hardware test that the UniBios has and didn't get any error messages. One of the RAM chips near the battery had three legs that appeared to be dried out and dirty or even corroded. I attempted to re-flow them but it didn't fix the problem. Before I mess with it anymore is there anything else I should check on the board that could cause the settings not to save?

 

[RetroTechRewind]

When you put in the coin cell battery/holder, did you also remove the 470ohm resistor? It almost sounds like a Backup RAM unwritable error. But, usually it won't boot when it detects that.

You can try powering it on with no carts inserted, then press P1 Start until you get to the "Clear Backup RAM" screen, press the buttons, then reboot.

Lastly, are you using any kind of multicart? They have a tendency to clear the backup ram on startup. Never heard of them clearing the clock settings though.

 

[GameLifter]

When you put in the coin cell battery/holder, did you also remove the 470ohm resistor? It almost sounds like a Backup RAM unwritable error. But, usually it won't boot when it detects that.

You can try powering it on with no carts inserted, then press P1 Start until you get to the "Clear Backup RAM" screen, press the buttons, then reboot.

Lastly, are you using any kind of multicart? They have a tendency to clear the backup ram on startup. Never heard of them clearing the clock settings though.

The 470ohm resistor was removed. I've tried clearing the backup RAM via the hardware test menu as well. The carts I've been testing with are Metal Slug X and Metal Slug 4 which are both legit. I tried testing it with Metal Slug X being the only game inserted and the results were the same. Only other thing is that the previous battery leaked and some parts of the board got damaged a little bit but the traces going to the RAM chips appear to be intact. I've got a multi-meter so I can test voltage to the RAM chips but I just need to know where to place the metal rods.

 

[RetroTechRewind]

Can you post a picture of the backup ram/battery area of your board? I might be able to help point you in a better direction

 

[GameLifter]

Can you post a picture of the backup ram/battery area of your board? I might be able to help point you in a better direction

Sure, I've attached an image I took of it last night before I tried re-flowing the dirty solder points on the RAM chip. I wasn't very successful in re-flowing the solder joints since I wasn't able to get much solder on them. Instead they ended up being covered in resin from the solder I was using. Fortunately this didn't ruin anything since the board still booted with no errors.

 

[system11]

The top one of the two looks to have a badly corroded ground pin, what voltage do you see reading across VCC and GND on that chip when the game is powered down? The original battery is 3.6v and you're giving it a 3v replacement, couple this with the resistive effects of corrosion and it may simply not have enough voltage to retain memory when off power. You need to see something greater than 2v across here for the low power memory retention to work.

 

[GameLifter]

The top one of the two looks to have a badly corroded ground pin, what voltage do you see reading across VCC and GND on that chip when the game is powered down? The original battery is 3.6v and you're giving it a 3v replacement, couple this with the resistive effects of corrosion and it may simply not have enough voltage to retain memory when off power. You need to see something greater than 2v across here for the low power memory retention to work.

With my multi meter set to 5 DCV it appears to read 5V but I'm not sure if I have it set right.

 

[GameLifter]

I had my friend look at the board and he couldn't find any broken traces and the correct voltage is getting to the RAM chips. He also retouched the legs on the RAM chip that were heavily corroded. Unfortunately this did not fix the issue. My friend mentioned that it could be the chip labeled HC32 that is causing the save issues. Is this a common thing?

 

[GameLifter]

Turns out the board is fine and the issue has something to do with the UniBios. I let my friend borrow my UniBios so he could test some boards and in exchange he let me borrow another BIOS (European I think). With this BIOS the soft dip settings save properly and remain there after a power down. Only thing worth mentioning about my UniBios is that one of the pins broke off when I tried re-seating it soon after I got it so I replaced the broken pin with a staple. Not sure if this would cause a problem but it's the only thing abnormal with my UniBios.

 

[Asirbike]

I have a question about my Neo Geo cab with an MV-2F board. It has been shutting off in the middle of playing after about 5-10 minutes. Has this happened to anyone else and if so what is the solution? Thanks in advance for any help.

 

[Razoola]

I don't see how the unibios can be causing this situation unless the unibios settings are not saving in the boards backup RAM because its becoming corrupted. Have you tried putting all the harddips on and letting the board cycle through the RAM tests?

Also, once you have set up a region with the unbios let the game start and then goto the ingame menu and then the memory viewer. Then Scroll to address 0xD00000 and take a screenshot and post it here (hold down a,b or d to speed scroll).

Raz

 

[GameLifter]

I don't see how the unibios can be causing this situation unless the unibios settings are not saving in the boards backup RAM because its becoming corrupted. Have you tried putting all the harddips on and letting the board cycle through the RAM tests?

Also, once you have set up a region with the unbios let the game start and then goto the ingame menu and then the memory viewer. Then Scroll to address 0xD00000 and take a screenshot and post it here (hold down a,b or d to speed scroll).

Raz

I tried the RAM test via the dip switches a while back and it returned no errors. Once I get the UniBios back from my friend I'll check the memory viewer. Thanks for the help!

 

[Xian Xi]

I tried the RAM test via the dip switches a while back and it returned no errors. Once I get the UniBios back from my friend I'll check the memory viewer. Thanks for the help!

How long did you let it run for?

 

[GameLifter]

I let it run for a good 20 minutes or so. Maybe a little longer.