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EBD GI lighting Issue

Posted: Wed Nov 15, 2017 8:30 am
by CftBL
Prior to MadRollin this year, I went through my Eight Ball Deluxe and I installed all new Comet Retro LED’s on the Topside and new incandescents under the playfield. About three weeks after MadRollin, the lower half of the playfield GI’s all were a lot dimmer than they should be; maybe 40-50% of their starting brightness.
Follow some helpful advice, I repinned the wires on the GI power connector and put a on new connector housing. The GI lights were still dim, I noticed that it was concentrated at the bottom and up one side. Ok, so maybe I had something hinky going on with a connection at a bulb or a wire. I then pulled the playfield and plugged it back into the GI lighting circuit. Nothing changed (I didn’t expect any changes), but this gave me unfettered access to the wiring. I checked the voltage at every GI light connection. It was a solid 6.9 to 7.0 Volts. Ok, so now I was really confused. All the lights had the proper voltages and solid connections all the way back to the power supply.
For comparison I put in an incandescent bulb next to a dim LED in one of the slingshots. The incandescent glowed bright like it should. Next I tried a new LED. It also glowed as bright as it should (see picture for comparison). I checked the resistance of the dim LED, it was ~41 ohms; the bright LED was ~23 ohms. I started looking more critically at all of my LED’s and realized that they all were dimmer then they should be. All of the extremely dim ones were at at least 40 ohms.
I cannot think of a reason that would cause all of the LED’s to increase their resistance. Is\] it possible to overpower an LED and shorten it’s lifespan? Or is this more likely just a bad batch of LED’s from Comet?

Re: EBD GI lighting Issue

Posted: Wed Nov 15, 2017 10:35 am
by TomGWI
I would just sell the EBD to me. :D ... arch=Retro
Check out the comet website. It even states the bulbs will not last long.

I use the Sunlight Frosted 2 SMD bulbs. Great bulbs. The sunlight white is great for anything from inserts to GI. I think even Neo likes them. ;)

Re: EBD GI lighting Issue

Posted: Wed Nov 15, 2017 10:41 am
by Chris K
Do you have any unused bulbs? You could plug one in to determine if the bulbs went bad. And if you have some other LEDs from some other vintage you could tell if the bulbs were bad as shipped.

Oh, and I'd totally help out by buying it, too. :D

Re: EBD GI lighting Issue

Posted: Wed Nov 15, 2017 12:30 pm
by CftBL
By my math the Comet Retro's lasted 180 hrs +/- 6 hours before they failed.
Even with a warning of not having a long life, this seems like an exceptionally short lifespan!

I'll check out the ones you listed. This was my first try of using Comet bulbs; I typically had purchased from PBL prior to this and thought I'd try something new.

Thanks guys!

Re: EBD GI lighting Issue

Posted: Wed Nov 15, 2017 1:57 pm
by Chris K
Your bulbs should last WAY longer than incandescent bulbs; burning them out shouldn't really be a thing in terms of hours, it should be a thing in terms of years. At home, many years.

There's a chance your bulbs were just bad, but it's much more likely there's a problem making them weak.

FWIW, the most dead LEDs I've seen on a table were on a Stern SAM table... of maybe 100 2-SMD bulbs, about a half dozen had one of their two SMDs dead. And that was on a table that had been on route for more than a year.

My home tables are mostly Comet LEDs, and I don't think I've had a single bulb die. I've had a few DOA, but not die after installation.