What's new
By:
Pinball info

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

wpc lamp matrix - fixed!

Max

Max

Site Supporter
Joined
Jan 18, 2023
Messages
133
Location
Lincolnshire
Morning folks.
I have an insert lamp in my White Water that refuses to work. I've replaced the bulb, diode and checked the holder both visually and continuity from the legs etc. All appears ok, all others are working fine.
I know it's possible for problems to be caused by another lamp/diode in the matrix but I'm not really sure what to check next.. Any pointers would be appreciated, the lamp in question is 77 Multi Jackpot (Insanity falls jackpot).

Thanks!

1699263482785.png
 
Check the wires on other switches in the same row and column. These are daisy chained and one may have come off or a bad connection in the chain.
 
  • Like
Reactions: Max
Check the pins at J137-7 and J133-8. Make sure they're not loose and with the game off try and press on the wires inside the connectors at these points.
 
  • Like
Reactions: Max
Dinsdale said:
Check the pins at J137-7 and J133-8. Make sure they're not loose and with the game off try and press on the wires inside the connectors at these points.
Click to expand...
Those connectors don't have anything attached in my game..

1699294052436.png
 
Dinsdale said:
That may be why. I do recall on WPC two of them are interchangeable. Try putting J138 into J137?
Click to expand...
Hmm I can see from the pic that at least 5 of the pins have been removed from J137 so I think swapping to that socket is out 😖
 
Max said:
Hmm I can see from the pic that at least 5 of the pins have been removed from J137 so I think swapping to that socket is out 😖
Click to expand...
Oh sorry, I didn't notice that. Now I see it. You may want to get that fixed, not that it is necessarily going to solve your issue.

You may need to reflow the solder on the back of the board. It may also give you a clue as to why those pins have been removed.
 
  • Like
Reactions: Max
Those sockets are not used
If only one insert is not working it wont be a board fault
As the lamps are looped in and out on the yellow and red wires check other lamps on the same rows and columns. Make sure a wire has not fallen off another socket
 
As per @Pick Holder , if it was your lamp matrix, a whole column or row wouldn't be working. If this is the last lamp in the row or column the cable may have a break between 77 and the one upstream from it. Otherwise lamp socket or cable loose at holder. If this is one of the mounted boards with the bajonet lamp sockets try bending the metal tabs up and reflow the solder they connect to - these tend to flow over time creating divots so the metal tabs don't make contact anymore. If this is the only lamp in the given column or row on the board it can also be the connector pins, their solder likes to break over time.
 
Thanks all for the help so far.
This lamp is a bayonet, I have checked the connections to other lamps on same colum and row. These are all ok as far as I can tell, a fair few of those are pcb mounted wedges so I can only really check the connection to the pcb, all look ok anyway and every other lamp works.
In test mode I do single lamp test and choose 77, there is voltage at the tabs on the holder.. this fluctuates quite a bit, I assume because it’s strobed? Looks like 10-12v. I’m going to replace the bulb holder as the next step, if I can find one.
 
Moonraker said:
Have you tried the general lamp test to help confirm it's not a board issue?

Williams WPC - PinWiki

www.pinwiki.com www.pinwiki.com
Click to expand...
If its only one lamp not working it wont be the board.

If he is measuring voltage I would say put in a new lamp holder and diode.

Make sure connections are correct as diode needs to go in series.

If you are unsure the way it goes - check another lamp holder. It could even be this lamp holder is wired incorrectly.
 
Good news that it won't be the board. I have a new holder on the way from PH, i'll update once it's replaced 🤞
 
I de-soldered a working lamp (extra ball) and connected it to the wires of the lamp that isn't working (77) - nothing.
I then attached the suspect lamp holder to the extra ball wires and it works.

Not sure where to go from here.. The orientation of the wires on the problem light are the same as another light on the same column:

1699466367329.png

Thoughts?

edit: If I remove the diode and just connect directly to the bulb then the lamp is on all the time (pulsing during startup/test when all other lamps are off). I suspect this doesn't prove anything other than the wires aren't broken.
 
Last edited:
Assume you moved the diode with the lamp holder? If so, follow the lamp cables and see if they are connected to the same colours at the next lamp over.
 
drhex said:
Assume you moved the diode with the lamp holder? If so, follow the lamp cables and see if they are connected to the same colours at the next lamp over.
Click to expand...
Yeah I left the diodes attached to the holders. The picture is of the working lamp on the same column, all of the other lamps on that column except these two are on a pcb, the colours match though. The wiring is a bit funny (single wires to the holders) as these are off a plug in extension (under the upper pf on white water) The lamp worked for a short while when I got the game so I’m guessing there can’t be too much wrong with the wiring really.
I’ve ordered a lamp matrix test board for the sake of my sanity.. I’ll update once I’ve received it and tested.

Appreciate all the help and suggestions so far.
 
drhex said:
Swap the cables.
Click to expand...
Sorry I don’t follow which cables, the ones attached to the lamp in the pic? Unfortunately I can't get to that whole section of wiring easily as it's under the upper pf (white water), I'd need to remove the ramps and upper pf.. I won't have time to do that for a while.

Just to recap, so far I have:
Put the holder and diode on another set of cables and they work, holder and diode are good.
Put a known good holder and diode on the 77 wires, nothing.
Removed/reversed the diode on the 77 wires, the lamp is then lit constantly. DVM measures 12v on the 77 wires.
 
Did you remove the diode or reverse it? Red should be on the banded side, yellow directly on the lamp. Follow the cables, make sure they end up on another, working lamp without any snags, shorts or similar inbetween. Cable colors need to be the same throughout the run. Pretty sure this is in the cabling as it is the end of the run.
 
I removed it for testing. I will see if I can get to the wiring without removing the upper pf and trace them as suggested, thanks again.
 
Thanks so much for the help everyone, I found the issue.. After tracing the yellow wire back through the loom I found the other end was attached to a lug on the GI string! I was sure the lamp worked when I initially bought the game but I was obviously mistaken.. Anyway, I removed the wire from that lug and soldered it to the yellow on the closest (same column) lug and it now works as expected. This has been bugging me for ages, really pleased to finally get it sorted. :thumbs:

Thanks again for all the help.
 
You must log in or register to reply here.
Back
Top Bottom