Yes.

Yes, I always install them with the power on and the game in test mode to illuminate all the bulbs.

If any of the sockets in a game have to be removed to change the bulb, always wrap your nut driver or screwdriver in electrical tape- so you don't short anything out.

Buy the LED's without polarity (you want non-ghosting LED's for the inserts anyways) and do it with the machine off.

I've seen numerous posts where while installing LED's the installer pushed the socket in and it shorted against something. Why take the risk.

If I have to use anything other than my fingers under the playfield, the power goes off. Better safe than sorry. It's REAL easy to rush, get frustrated, or get complacent doing those menial tasks. That's when "it" tends to hit the fan.

Yes. And be careful with tools or sockets you remove.

Otherwise you get to learn the fine art of CPU repair.

LTG : )

Yep, led'd ST25 and must have bumped some switches against something while poking around in there. Blew same column in the matrix TWICE!