A multimeter test will tell you if the diode is good or not.

If you have to transplant a diode, just use a new one instead--it's not worth the trouble to transplant it. Also, it's easier to make a good mechanical connection with longer leads between the leads and contacts prior to soldering.

If it looks like it's bulging or damaged, I replace it.

Diodes are dirt cheap.

Yep, diodes are cheap. I'd replace it, and it'll be easier with a new one.

Solder the diode on first, then solder the row wire(s) to the non-banded side of the diode. Green/XXX column wires are usually slide on, but they go on the middle lug. Use quality solder, makes a world of difference when trying to solder the row wire(s) in machine. I use Kester 24-6337-0027 44 -- great stuff.

MagmanMIke,
Mouser Electronics

Great Plains Electronics is great for most things Pinball specific.

Digi Key

Really depends where you are located & your knowledge of the Electrical parts you need, Mouser Parts usually get to me in 1-2 days max, Digi-Key 3-4 days, GPE, 3-4 days.

Ed @ GPE has supported Pinball for a long time.

There are lots more Electrical Parts suppliers, these are the 3 I use the most - with Mouser being local to me if I order on a Monday before 7PM I'll usually have my parts on Tuesday from UPS.

Kim
www.KimballsPinballs.com

I highly recommend putting a new diode on a new switch. They are dirt cheap.
They can be damaged by removing them (broken inside or what ever) and they can fail eventually.

Just gives you peace of mind to replace that 20 year old diode since you have to remove it anyways.

Pinball bulletproofing so to speak.