From Newsgroup: rec.games.pinball

Having a fun time tracking down why this is happening on a Dr. Dude I just picked up:
The "Jackpot Ready When Flashing" lamp is illuminated at all times, except in test. During single lamp test said lamp seems to ghost randomly a different times. Also the mix master "Heart" (red lamp) stays illuminated when at times when running through single lamp test, which is the reason for the thread title of two lamps lit simultaneously.
I have so far tested all the TIP 102 & TIP 107 in the lamp matrix = ALL GOOD. Update:
I found what indeed appears to be a short when continuity checking the playfield connectors, with the offending column #8 (YEL-GRY) and the offending row is #1 (RED-BRN). And yes, I have the WPC version of Dr. Dude....not that it really matters for this particular problem. I am thinking I have a shorted diode, bad lamp wiring, or just a plain old short somewhere on one of those two lines.
So, next I am going to go through each lamp in Column 8 and Row 1: Individually.
My plan is to test each diode, and to make sure each lamp is wired properly while checking for obvious shorts.
It's been a hell long time since I've had to track a down a WPC controlled lamp problem, so any other suggestions would be welcome!
I will report back once I have more info, would love some feedback in the meantime.
Thanks in advance -
Pete Hoerber - Seattle
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From Newsgroup: rec.games.pinball

On 6/21/20 7:30 PM, tacxboxflash@gmail.com wrote:

Having a fun time tracking down why this is happening on a Dr. Dude I just picked up:

The "Jackpot Ready When Flashing" lamp is illuminated at all times, except in test. During single lamp test said lamp seems to ghost randomly a different times. Also the mix master "Heart" (red lamp) stays illuminated when at times when running through single lamp test, which is the reason for the thread title of two lamps lit simultaneously.

I have so far tested all the TIP 102 & TIP 107 in the lamp matrix = ALL GOOD.

Update:

I found what indeed appears to be a short when continuity checking the playfield connectors, with the offending column #8 (YEL-GRY) and the offending row is #1 (RED-BRN). And yes, I have the WPC version of Dr. Dude....not that it really matters for this particular problem. I am thinking I have a shorted diode, bad lamp wiring, or just a plain old short somewhere on one of those two lines.

So, next I am going to go through each lamp in Column 8 and Row 1: Individually.

My plan is to test each diode, and to make sure each lamp is wired properly while checking for obvious shorts.

It's been a hell long time since I've had to track a down a WPC controlled lamp problem, so any other suggestions would be welcome!

I will report back once I have more info, would love some feedback in the meantime.

Thanks in advance -

Pete Hoerber - Seattle

I find this procedure helps me with matrix issues. The video is great, too.

http://homepinballrepair.com/index.php/pinball-switch-lamp-matrix-troubleshooting/

--
http://orcalcoast.com/
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From Newsgroup: rec.games.pinball

Hey man! Thanks much for that!! It was actually an old RGP post of yours from several years back that inspired me to try to fix this.
So I got lucky here-
Turned out to be a combination of a blown diode on the 555 lamp socket PCB for the offending lamp that was constantly lit or ghosting. Also, instead of the column wire going to the correct solder pad, it was connected to the diode directly! This likely shorted the diode too.
It's bizarre the other ghosting/dual lamp lit issues this caused outside of the row and column that tested as shorted. I say I got lucky because that "Jackpot Ready When Lit" was the first lamp in the string, -- when the hell does that ever happen?!
On first inspection, it looked correct but then I took it the socket PCB off and it was pretty obvious. Diode also tested as shorted. I suspect the column wire came loose and someone tried to do an "on-the-fly" fix and simply...missed.
I hope this helps someone down the line, and for someone with a life long love of pinball: There is NOTHING like the feeling fixing your own machine. Nothing.
Thanks again for your reply!
Pete
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