The bad battery thread

[DrHuxtable]

First I removed old battery along with the 220 resistor, but this hadn't the effect I expected. With the power on the voltage on the anode of the 1S1588 was 0V, but on the cathode it was still 4.2V? The + side of the battery holder also give 4.2V.
Then I tried to find out what the HRP100 was. By the symbol it should be a zener diode but Google couldn't find a datasheet? So I desoldered it, and looked at it with my loupe. There it says: S4`3D. Can't find anything about that either. (S4 should be SMD?)

Then I took a leap and desoldered the 1S1588 and put this to replace the HRP100. Now I think this works, with power on the battery + from the cr2032 holder is 0V, the backup RAM had 5V. With a battery in the holder, the battery + gives 3.5V. The RAM still gets 5V of course.
With the power of and the battery in place, the RAM get 3.2V.

Is this really what needs to be done on the MV4FS? Throw out HRP100 and put 1S1588 in its place? Does 220 get removed as well?

 

[Xian Xi]

I read through but I'm still confused. Is there a consensus about the MV4FS battery? Mine is a coin rechargeable lithium WITHOUT jumper. What resistor do I pull? Thanks.

The coincell type rechargeables rarely leak so if you don't need to replace it then just leave it be unless you are upgrading it to a bigger capacity one.

 

[DrHuxtable]

I just got the board from ebay and it's leaking bad.

 

[Xian Xi]

That sucks, well if you put in a non-rechargeable then pull the 470ohm resistor to disable the charging circuit.

 

[DrHuxtable]

That's the topic of discussion. The MV4FS is apparently different. The area around the battery is slightly different than the other 4-slot version. No 470.

 

[Xian Xi]

It's pretty much the only resistor in the area. It's the only directly connected to the plus side of the battery. Might be a 330ohm.

 

[DrHuxtable]

The closest one is the HRP100 as Hairy Otter mentioned. Then 1S1588 to RD3.6ES. I would send him a PM but I'm too new apparently.

 

[DrHuxtable]

After RD3.6ES, the trail ends at a 220 if I'm looking at it correctly.

 

[DrHuxtable]

Does this help? Pink line is the trace underneath. It ends at the 220 resistor.

 

[Hairy Otter]

Does this help? Pink line is the trace underneath. It ends at the 220 resistor.

Here is how I did it:

I took out the zener diode hrp100, the diode 1s1588 along with the resistor 220. Then I but the dionde 1s1588 where the zener diode used to be.

How I came up with this you can read here: Primary Post

The end result looks like this:

 

[SmokeMonster]

I changed out my MV2F's generic 2032 battery holder for one that sits flat. This type is really nice and you can get 4 for $1.36/shipped on eBay.

 

[lions3]

Just took the foam off around the battery on my 2 slot and notices the solder points have a little discoloration and yellowing. I'm assuming this means the battery may have just started to leak. Anything I should add to the solder points to neutralize any potential acid? I've checked the board and can't see any damage anywhere. So far everything else on the board looks perfectly clean. Any common points I should double check?

EDIT - After removing the battery and cleaning the connections everything looks good. I just followed some advice from earlier in the thread and used vinegar to neutralize any battery leak then used water repeatedly to remove the vinegar.

 

[Xian Xi]

Just took the foam off around the battery on my 2 slot and notices the solder points have a little discoloration and yellowing. I'm assuming this means the battery may have just started to leak. Anything I should add to the solder points to neutralize any potential acid? I've checked the board and can't see any damage anywhere. So far everything else on the board looks perfectly clean. Any common points I should double check?

EDIT - After removing the battery and cleaning the connections everything looks good. I just followed some advice from earlier in the thread and used vinegar to neutralize any battery leak then used water repeatedly to remove the vinegar.

If it's yellow, it's most likely just flux. Most times the corrosion would be on the parts side and will look greenish or fuzzy.

 

[Yrouel]

I like to collect vintage machines and buying certain ones untested is always a huge gamble because of these damn batteries. For example finding a working or even salvageable Amiga 500+ is really difficult.
Anyway, I prefer to replace rechargeable batteries with super caps they are basically drop in replacement with no hassle of modifying the circuit to use the usual CR2032.

 

[gamerwhat]

Does the battery recharge itself if the powersupply is turned off but plugged into the power outlet?

 

[Yrouel]

I finally took pictures of my supercap (EECS5R5H155) mod. I put back the plastic cover after removing the black foam (and cleaning up the residue) using small blobs of hot glue in the corners.

 

[Hairy Otter]

Does the battery recharge itself if the powersupply is turned off but plugged into the power outlet?

The power used for charging the battery is the same as what makes the board run. So the battery isn't charged when the power supply is off. In arcades the machines where running trough most of the day, plenty of time to charge the battery for the short night break.

 

[Niko]

So every MV-1C I have tested drains the backup battery extremely fast. A brand new 2032 would only last about ~5days. To counter this I used a 4400Mah battery pack and recharging circuit. On a full charge I can get around ~50 Days without powering the board up. This is nothing compared to the year(s) i'd get from the older boards. But its a good medium, especially since its unlikely I'd go more than 50 days without playing neo, and if I did its no big deal. Next time I power it up the battery will charge again.

 

[Lach]

Niko, what sort of enclosure is that? Your 1C is sexy.

 

[RetroTechRewind]

Niko, what sort of enclosure is that? Your 1C is sexy.

Looks to be the inside of an Omega. And you're right, they're sexy as hell. I love mine.

 

[xsq]

Curious, my 1FT doesn't drain the coin cell I put on it that fast... did that 2+ years ago and it's still OK.

 

[Niko]

Niko, what sort of enclosure is that? Your 1C is sexy.

Thanks! Its an Omega CMVS.

Curious, my 1FT doesn't drain the coin cell I put on it that fast... did that 2+ years ago and it's still OK.

Yea I've had tons of MVS boards that didnt drain batteries like the 1C does. Apparently it has something to do with the backup RAM used on some versions of the 1C. Whatever it is, it fucking sucks.

 

[Lach]

Thanks! Its an Omega CMVS. .

I am both sad and happy, so damn neat!

 

[channelmaniac]

Thanks! Its an Omega CMVS.



Yea I've had tons of MVS boards that didnt drain batteries like the 1C does. Apparently it has something to do with the backup RAM used on some versions of the 1C. Whatever it is, it fucking sucks.

What's the part # on the offending RAM?

 

[bartre]

well I got this in this week.

I've already pulled the battery.
does it matter what kind of vinegar I use? I don't have any regular white.

I contacted the seller yesterday to work something out; I'd rather just fix it and be done.
but what's a fair price for a board with this kind of damage?