I'm getting SO CLOSE on this playfield swap I can taste it (which may or may not be a good thing on Playboy...)

So - I have ONE LAMP that refuses to light. There seems to be some weirdness on the circuit but I can't put my finger on it. Its bulb Q27, the "6" bonus on the playfield (right in front of the right flipper..) I have an Alltek board (if that is relevant) and am using the test board to manually cycle through to the specific bulb to test.

Every other lamp works as intended on the playfield - I went through then entire loop and checked each one.

When I illuminate lamp Q27 (the # 6) I am positively getting power from the pin on the board. I can connect a test lamp to the pin on the board to the backbox ground and it illuminates as intended. However, when I try to connect from the board pin to the ground braid wire on the playfield, it's no good. I Idid try to connect in several place on the ground braid.

Running from the board pin the socket separately doesn't help either. No other lamp shows this issue.

- Yes, I did try a known good bulb
- I did check continuity on the white - blue wire from the plug in the backbox to the socket on the PF and we're good there.

I'm not sure where else to go on this. Like I said, every other light works fine. I'm not sure if i'm missing some test but I can't think of what's missing here.

Yes all new lamp sockets

No (if I understand what you’re saying - taking current from the wire at the socket to the ground braid?)

OK thanks every for the thoughts!

Here's all the tests I could think of to try, hopefully something here indicates a thought:

PF Socket Tests
Test 1 - Bulb 27 tab (White / Blue wire) -> 5V rail in backbox = Test light YES!...Bulb in socket on playfield NO

Test 2 - Bulb 27 tab (White / Blue wire) -> Braid on Playfield (Ground?) = Test light NO ...Bulb in socket on playfield NO

Test 3 - Bulb 27 tab (white / Blue wire) -> Tab on Q28 (bonus 10) = Test light NO... Bulb in socket on playfield NO

Light board tests with a test lamp

Test 4 - Q27 pin on light board -> 5V backbox braid = Test light YES!

Test 5 - Q27 Pin on Light board -> Solid blue wire on PF that is attached to the ground braid ON PF = Test light NO

Test 6 - Q27 Pin on light board -> 5V rail in back box = Test light YES!

Hope something jumps out here??? my first blush is that something off with the playfield ground bread, but EVERYTHING else works right???

I'll try to get a picture tonight after work, but what I'm saying is that when I try to illuminate the Q27 bulb (#6 bonus), and connect a test light from the white/blue wire to the playfield braid that is the same braid connected to the other bonus lights that all work correctly, nothing happens. When I connect from the white/blue wire to the backbox braid, the test light works. I've never been able to get the actual bulb in the socket to light (though I have known good bulbs in the socket).

I keep thinking there's a continuity issue on the white/blue wire, but I have checked it with a meter and have continuity.

I definitely do not have the GI ground wire anywhere near the bonus bulb sections.

Definitely will do. THANKS IN ADAVANCE ! for the help!!

OK Going to ask a dumb question - can you help me understand how to do that? Which legs on the board transistor to what? (Sorry for the dumb question..)

OK I think I got my homework done!

Test 1 - Board test - Q27 activated in lamp test mode, Meter set to V~. Attached the negative lead of volt meter to large ground strap running through back box and red positive lead of voltmeter to each transistor tab -- THIS sounds potentially borked?? Left leg is 0; Middle leg is 3.3v; right leg is 128.9mv ????

Test 2 - White/Blue wire soldered on socket tab to ground braid in cabinet - Test light illuminates IMG_0075 (resized).jpeg

Test 3 - Jumper from Q28 tab to Q27 Tab - BOTH lights illuminate (Q27 REALLY BRIGHTLY!)IMG_0074 (resized).jpeg

Test 4 - Run Jumper from White/Blue wire soldered on socket tab to Test socket attached to ground braid in cabinet - First the test light illuminated, then the Q27 bulb flickered on weakly??IMG_0076 (resized).jpeg

Update - so, at this point I’m calling the board borked. Turned it on this afternoon to rethink this, and now I have no feature lighting. Tried a second known good playfield I have, and it’s the same thing.

Ordered a new board (yes I know they’re warranted, just hadn’t heard back yet and need to get this going).