Which is main Battery

[t28c34]

Picked up a new project cheap. I'm guessing this is a S2000 right? I haven't got a hold of one yet. I was right it just needed a re-set and battery. Which is the main battery? What board is this? I see the Varta battery needs a little TLC or replaced? The little Sanyo battery is welded on. anyone know what that size that one is before I take it off if need be?
Thank

[lookes]

Looks like you have an S2000 504B MPU
The main battery is the coin cell. Get a coin cell holder and install a CR2032 coin cell.
You need to remove the larger (Varta) battery and U79. That battery may have already caused board damage.

[t28c34]

Remove and replace the Varta? or just remove? I thought I read somewhere that it could be removed.
Why U79

[lookes]

Yes just remove it.  The coin cell needs to be on the board.

[t28c34]

swapped out the main battery and removed the Varta. After starting up, I got a close door message that I trouble shot down to the possible tracers from the corroded Varta. Cleaned up the area really good with contact cleaner and re installed. Machine came back to life and is running perfect. Thaks for the help!
 

[lookes]

That's great! You caught it before there was major damage.   

[Brewchap]

Cleaned up the area really good with contact cleaner and re installed. Machine came back to life and is running perfect. Thaks for the help!

Contact cleaner will not neutralize the alkaline. You will need to use vinegar or stronger stuff to neutralize the alkaline. Sand the affected area to get in to the crevices, rinse with water, and dry with alcohol.

[t28c34]

Sounds good Brewchap, I need to pull it again and anyway to solder in a cr2032 battery holder. I just have it temporarily rigged waiting for them to come in.

[Brewchap]

Here is a link that you can read, It's pinball related but battery damage is still battery damage no matter what your working on.

https://www.pinwiki.com/wiki/index.php/General#Abating_Alkaline_Corrosion

[t28c34]

Thanks, I'll look into it.