The left back corner of the GI in my Road Kings has been out. Yesterday I found a bad fuse so I replaced it. The GI worked, I thought I had fixed the problem. Tonight I thought I will replace any bulbs I see out; only found one so I replaced it, fired the game up, thought all was well only to find that same section of GI was out again. I immediately looked at the fuse and it was bad again. I put a new fuse in and tried again. I noticed the lights on this part of the GI were barely lit and then I looked up and saw the fuse get red hot and then blow.

To start diagnosing I removed the bulb that I replaced, still blew the fuse. I thought maybe that socket went bad so I checked for continuity and it had a completed circuit so I removed one wire from that bulb holder and it still blew the fuse. Come to find out all of the GI on the game that I tested shows continuity and as I found the only way it doesn't is if one of the wires is de-soldered from the holder so to me this makes finding a bad bulb holder difficult.

I've narrowed down the problem to somewhere on the playfield because I found the connector that goes from the backbox to the playfield, disconnected it and it doesn't blow the fuse.

Can someone tell me what is the best way for me to track down where the short is occurring? I gave all of the GI using these wires a good visual inspection and nothing jumped out at me.

Any help or guidance would be much appreciated.

I was wondering if this is what it would come down to or if there was an easier way, which it sounds like there isn't. Thanks for the guidance LTG!

Last night I was thinking of doing something like this, but if the problem is the socket it will still blow the fuse even if there isn't a bulb in it right?

No I did not have the PF out, but when I was working on the game I discovered the bulbs you are talking about, I will make sure to check them. Thanks for the reply and heads up!

^^is what it was! The funny thing is I never had the PF out. Last night I pulled all the bulbs and it still was blowing the fuse. I then unplugged the harness for the lights that are on the backboard and the fuse didn't blow so next I unscrewed the backpanel and gave the lights a good looking over and found one of the leads for the light was bent over and barely touching the housing causing the short. It must have just been barely touching also because I hooked my DVM up to it and I had to push on it ever so slightly to get it to show continuity so that must have been why it would go from frying the fuse and then not frying the fuse between the different times of me lifting the PF to work on the game.

A big thank you to everyone that told me what to look for and how to go about conducting my diagnosis!

This is the socket that was causing the short. The picture was taken after I straightened it, but the lead on the left was bent up and ever so slightly making contact with the bulb holder.

IMG_20170404_192324152 (resized).jpg

Yes sir, I like to close out my tech threads once the problem is resolved in case someone else in the future has the same problem and it can help them, that is the true power of a technical forum in my opinion.

Thanks again and have fun playing pinball! I had a good time playing Road Kings last night with all of the GI working