(Topic ID: 150520)

Lamp matrix row ghosting...


By bhwolf

3 years ago



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  • 20 posts
  • 6 Pinsiders participating
  • Latest reply 10 months ago by scottholdren
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#1 3 years ago

I have this love/hate thing going on right now with my machines. I decided to pick up a Rottendogs PDB to have as a spare/temp board so I could take my time with other repairs as they come up. The original still works, but it needs a little TLC and some repining.

Anyway, I swap in the new RD PDB ... and notice I'm getting ghosting on other LEDs on the same row in the matrix. Ghosting may not be the right term, but in this context I'm meaning lamps that should be off are glowing slightly. For example, on my ToM, 56 (Start Illusion) lights fine, but then 66 Safe Escape ghosts. 66 causes 76 Illusions to ghost, and 76 causes 86 Shoot Again to ghost. This happens on every row -- 14 causes 24 to ghost, 24 causes 34, etc., but not necessarily every lamp. (The LEDs are Cointaker non-ghosting.)

Naturally I thought it was the RD board as I didn't recall seeing this before. I pull it, swap the original back in. Turns out the ghosting is still there, but much fainter and barely noticeable.

So, not sure if this is a short, a diode, or other issue. I've bookmarked a few pages that discuss lamp matrix troubleshooting, but because I'm seeing this across so much of the matrix, not quite sure where to start. Any tips?

#2 3 years ago

If you are seeing it across a lot of the matrix, that is not likely just one or two simple causes such as a failed LED. In some cases, using anti-ghosting design LEDs can alleviate the problem...but not always. For WPC based games, there are some specific "fixes" you might look into. Some info here: http://www.edcheung.com/album/album07/Pinball/WPC_Ghost_Busting.pdf

I'm not well versed in WPC ghosting but I can tell you ghosting problems can vary from game to game, and can vary depending on the LEDs used. My Williams System 11 Taxi ghosted terribly on almost all lamps with standard CTs, the only fix for me was to remove them - while on other games I didn't have the problem. F-14 Tomcat worked flawlessly with the CT premiums. Just my personal observations.

#3 3 years ago

I just spent a couple hours on similar with my DEST, so here we go,,,

Look at your matrix map, are all the faintly glowing bulbs or the same row or column?

If not, then I can't help you

If they are, then go into lamp tests. From there step through each row test.

Does your 'bad' row glow when any other row is selected?

If it does then you have either a shorted or missing diode on the 'effected' row. What happens is you are getting small spikes fed back into your effected row.

I beat myself up testing each row/column driver, testing each diode on the row under the playfield, double testing every diode on the bad row, swapping the return wire between rows at the driver board as a test to see it I was going crazy and it stayed with the playfield, then I found it.. Someone wired the lamp in the autoplunger button directly without a diode!!! /facepalm

#4 3 years ago

Good info, thanks!

OK -- here's what I observed. Each row test seems fine, but the column tests show the problem -- for example, with Col 6 on, many of the lights in Col 7 are very dimly lit. If I go into the single lamp test, testing for example 62 will have 72 glow.

One oddity I noticed (and placement here made this easy to spot, might be others I can't find) -- I'm seeing the shoot again #86 LED light and flicker dimly when -any- column is selected, but NOT any row (other than the row it is on, which turns it on). Not sure what that points to (if anything)...

#5 3 years ago

Before I'd worry about ghost busters or code, I'd ohm out the diode #86.

You should read open in one direction and about .5 ohm reversed with meter on diode check. (or compare to others)

#6 3 years ago

bhwolf. do yourself a favor and remove 2 LED's from the row. If the ghosting stops it may be a bad resistor on the board. I had a similar problem where if the row had incandescent bulbs installed, it was fine. But when I installed LED's I started having the problem only when the row was full of LED's

#7 3 years ago

Thanks all --

I spot checked the diodes and did a continuity check -- all seemed ok from what I tested (not thorough, just spot checked looking for anything obvious). Most of the lamps are on PCBs, so I unplugged those and no change.

Gundam -- will try that, but did something similar and no luck (plus, it's with both driver boards).

Is a certain amount of ghosting normal for LEDs in these WPC machines? With the original board in there, it is so dim through the inserts I never noticed it. But with the RD board, it's a bit brighter and more noticeable.

#8 3 years ago
Quoted from bhwolf:

Is a certain amount of ghosting normal for LEDs in these WPC machines?

Yes. It you use cheap non-non-ghosting bulbs.

With Ghostbuster type leds, LED's not so bad. (good)
With patched game code, about negligible. (better)
With LED OCD, no ghost at all and a much nicer experience as it will waveshape the LEDs to act like incandescent. (best)

#9 3 years ago
Quoted from Patofnaud:

Yes. It you use cheap non-non-ghosting bulbs.
With Ghostbuster type leds, LED's not so bad. (good)
With patched game code, about negligible. (better)
With LED OCD, no ghost at all and a much nicer experience as it will waveshape the LEDs to act like incandescent. (best)

I've got Cointaker Premium non-ghosting LEDs in there, so wouldn't think they would ghost. I was thinking of an LED OCD to reduce the harshness a little, so maybe I should just go for it.

#10 3 years ago

Update... Thought it would be a good idea to verify these were non ghosting LEDs and long story short, they aren't. I asked cointaker and got a quick reply. I didn't realize that was an upgrade option, as the main site has the ToM it I ordered listed as premium non ghosting, but guess I ordered from their older site that didn't have them listed as non ghosting. Great. Time from LED OCD.

#11 3 years ago

Actually, for best LED OCD experience you want the cheap non-ghosting bulbs.

So you are all set.

#12 3 years ago

Though it is not an end all be all, but j have heard that there is some software out there that will repair the game code
For the lamp matrix and the ghosting issues. It does work on Bally games, all you would need to do is burn the code to a new chip

#13 3 years ago
Quoted from Gundam_Pilot_:

It does work on Bally games

It works on STTNG (similar game) or so I heard.

#14 3 years ago

Yes I have heard that as well.

#15 3 years ago

The patch will work on any WPC game that doesn't already have the fix in the original code. There's a particular date (that I've forgotten) where any ROMs released after will already have the fix applied by Williams.

For the OP, he doesn't need to worry about the patch at this point since the LED OCD will work equally well regardless of the patch.

#16 3 years ago

Thanks everyone, and herg my order has been placed (and shipped already too ) ....

In the end will probably work out best that the cointakers aren't non-ghosting -- and for anyone who stumbles on this post, be careful of which site you are on -- the new or old one -- when ordering from cointaker to make sure you're getting ghosting or non-ghosting ... it can get confusing.

Despite the ghosting, I had a couple complaints about the LEDs being a bit harsh on the machine and why I was considering an LED OCD prior to finding this ghosting issue. I had put some softer, frosted LEDs in the GI where directly visible but it didn't make too much of a difference. This should fix things up nicely!

#17 3 years ago

LED OCD will make the insert less harsh, but GI will not change.

Herg makes a GI OCD but that will fix dimming issues on GI. Nothing can fix glaring bright in your face GI bulbs. GI OCD can 'help' a bit by allowing you to dim them a bit, but the best thing for glare is to use a less harsh bulb.

#18 3 years ago
Quoted from Patofnaud:

but the best thing for glare is to use a less harsh bulb.

For really obnoxious locales, another option is to try using a bulb cap over the LED to cut intensity down.

pbl_03-8063-xx_(resized).jpg

#19 3 years ago
Quoted from Patofnaud:

LED OCD will make the insert less harsh, but GI will not change.
Herg makes a GI OCD but that will fix dimming issues on GI. Nothing can fix glaring bright in your face GI bulbs. GI OCD can 'help' a bit by allowing you to dim them a bit, but the best thing for glare is to use a less harsh bulb.

Yep, I decided to get the GI OCD as well ... by the way, herg, I ordered the GI OCD a few hours after my LED OCD order (might as well go all in, I figure), and noticed you refunded the shipping on the second. Classy. Thanks

For a few of the GI LEDs that were directly visible (about 8 or so), I put in frosted LEDs so they don't seem like freakin' laser beams. But I think having them at 85% brightness (give or take), plus making the flashing a bit smoother for GI effects will help. We'll see! If I'm lucky they'll get here Saturday and I can swap them in over the weekend.

2 years later
#20 10 months ago

Found this old thread researching a similar problem on World Poker Tour. Column #1 was flashing dimly along with column 3-8. This was after redoing all of the inserts with Cointaker frosted premiums. Tracked it down to a single incandescent bulb in the credit button. Switched that to an LED and problem went away. I tried adding a diode to the credit button lamp but that didn't fix it. FWIW.

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