Hey Guys. Just finished up an Eight Ball and have a weird question about some lighting. I initially replaced all of the lighting with LEDs but quickly found out this wasn’t ideal and now have gone with GI only. The “3 alley” light at the top only works with an LED, not incandescent. Voltage across the lamp socket measures 5.5V without a bulb. I have tried multiple known working incandescent bulbs with the same result. New lamp driver board. All of the other inserts work without any issue. What am I missing?

So I have replaced the lamp socket with the exact same result. If I ground the socket, an incandescent bulb works. Voltage still measuring 5.5v with no bulb. Barely any voltage with a known working incandescent bulb (~20 mV). I feel like this has to be the wiring or the lamp socket but I have now replaced both. I am stumped. Anyone have additional thoughts?

Good idea. Thanks for the help. I will keep you posted.

The switched voltage at the other incandescent lamps all measure about 4.9V. The socket in question measures zero voltage with a known working incandescent bulb in place and not lighting. Measures about 5V with no bulb in place.

I have now replaced the socket, the wire between #2 and #3 controlled lamps. The additional controlled lamps wired in series #4-12 light incandescent bulbs without an issue. The #3 lamp socket appears to be getting the same voltage and current as the other lamps but will only light the LED, not the incandescent.

I am very confused. Nothing seems to add up. Any ideas what I am missing?

Anyone have additional thoughts?

Thanks for your help.

I replaced the wire (yellow/black) from the #3 to the connector J3 on the lamp driver board with no change. I resoldered the lamp socket #1 with the teal power supply. No change. I replaced the connector for the power supply (teal) on the rectifier board. No change.

I switched a known working bulb from #1 and #2 lamp socket to #3 just to make sure. No change but now when I replace the incandescent bulbs #1/2 they do not light. If I ground the lamps #1/2/3 they all work. All work with LEDs. So weird. Board issue?

I switched the Alltek board for the original lamp driver board and all incandescent bulbs in all lanes work - no issues. Do I have to replace the Alltek board? Pretty new. Purchased in 2021. I am now assuming this must be an issue within the board.

I would love to hear anyone’s thoughts. Thanks.

So I sent the board back to Dave at Alltek who tested it and found three bad SCRs. He just sent a new board - super quick, very responsive and great service. Plugged the board in and everything works except the one controlled lamp in the #3 lane. Back where I started. What else could I be missing?

New board, new socket, resoldered all wiring, new crimped terminal, ran an entire new wire from the lamp socket to the board - all with no change. I can still ground the lamp socket and the bulb works. I feel like this has to be something very unusual.

Any thoughts at this point are appreciated. Thanks.

Uggghhhhh……..I figured it out. Loose crimp on the yellow and black wire . So easy, yet so hard. Thanks guys.