Morning everyone,

First off... I'm brand new around here and would like to apologize in advance for any gaffs.

I've just blown the dust off of a '78 House Of Diamonds that was in my house growing up and been under a drop cloth for 30 years. I have a 13 year old son that's super keen to get it running and he and I are going to (attempt to) tackle whatever it needs on our own.

I don't know why I expected it to just start working when we plugged it in, but other than the odd playfield light coming on, it wouldn't accept coins so we quickly turned it off and started our research which of course pointed me almost immediately to the battery on the board as our first culprit.

The battery is still putting out a slight current but nothing near the 3V+ it's supposed to and there is definitely some corrosion in the immediate vicinity of the terminals, but fortunately nothing seems to have travelled far and the surrounding components seem unaffected.

I've desoldered the battery and cleaned the board up and I believe we're ready to install a replacement.

I've ordered a CR2032 holder and what I believe is the correct diode (1N4148) to prevent battery charging, but this is where my question comes in.

Nowhere online have I managed to find a definitive and clear explanation of how these two components need to be connected. It's worth mentioning at this point that I have only the most rudimentary knowledge of electronics and desperately want to avoid harming the machine, but both my son and I are eager to learn.

Clearly if I was installing a rechargeable battery, I'd just connect the positive and negative terminals from the replacement battery to the spots on the board where the original battery was and we'd be done with it, but it's the location and orientation of the diode that has me stumped.

It seems that battery replacement is a very common operation so I'm hoping that somebody on here has some experience and tips for a pair of newcomers.

Thanks in advance!

Jeff

Thanks for that. I suppose if I went the capacitor route it's an easier install as it's just a direct replacement. My next question I suppose would be regarding the rating of the cap... that article suggest a 5.5V capacitor, but the battery I've removed is 3.6V. I just want to make sure I don't cook anything

Thanks, @quench. This is super helpful and exactly what I was looking for. I've compared that schematic to my board and definitely see exactly what's going on now. If the D3 replacement is going to improve things, I'll definitely look into getting a replacement component and making that change. Like I said, this is a hobby that my son and I are looking forward to and anything that we can do to improve this cabinet we'll tackle.

IMG_2554 (resized).jpg