Thanks guys...I have coming in...meanwhile I'm gunna go soak this scrap in vinegar and baking soda
Although the battery was long removed, the damage was already done.
Look at the Q1 chip...it's split in half....anyone know what it's for?
Looks like a small switching transistor of some type.
I'm wondering if it has anything to do with the "Coin-n" error?
Board is a Super Stepper Controller ASSY NO 7551050 or goes by the nickname "502 board"
Only schematics I have is for the ASSY NO 75510502 - which is a little different....maybe lol
Anyway, this sheet shows the [Q1] as ...>>> Q1-4,8,10 XTR,NPN,MMBT3904,SOT2
MMBT3904 is either a switch or an amplifier chip...I'm gunna guess it's a switch because there's three acid-eaten traces going to it's 3-pins.
***Edit*** I've identified it...the markings are "1 AM Z"
Mouser.com said it as a "bi-polar transistor"....I laughed and said I know people like that...haha
The guy laughed on the phone too...lol
Anyways, he directed me to Allied Electronics so I went check there.
Found it at Allied Electronics for 3 cents apiece...the letter "L" is just a date marking a few years older than the "Z" I have on mine...>>>
https://www.alliedelec.com/product/on-semiconductor/mmbt3904lt1g/70099530/?gclid=EAIaIQobChMI4rrd_tSA5QIVCmyGCh2idQNwEAQYASABEgL_yfD_BwE&gclsrc=aw.dsData sheet...>>>
https://www.alliedelec.com/m/d/1a5811649abd01351be5b86b87f7b036.pdf