Quoted from GKW:Update:
-repaired old, original lamp driver board (replaced 10 corroded SCRs) and all of the controlled lighting now works properly (no more locked-on lamps).
-replaced 8 sockets on lamp door in back box. This is the area where I narrowed down where the short was coming from, that caused the GI lighting to short.
Now, I am not so sure, because after I installed new lamp sockets, I am still getting a short with those same sockets and the GI lighting fails. To make
matters worse, as I was trying to narrow down which socket(s) was causing the failure, the entire GI went out, without popping the 20 amp fuse. Now, every
GI light is dead and I am back to my starting point, only worse now.
The coin door was the first place that I checked for problems associated with the GI failure and nothing there is causing it. I suspected this area first, because I have the lighted flipper button mod installed. Everything was working fine, with the exception of the locked-on playfield lights, until I installed the Alltek LDB.
I found a thread on the internet, discussing Alltek boards and how they are very stringet in power distribution. The article was focused on the Alltek
Solenoid Driver Board, but could this be my problem as well? I am running Alltek MPU and SDB, but it is only when I started running the Alltek LDB that I started having issues with game resetting. Now that I have the original LDB installed and GI lighting is dead, do I need to look at the Alltek SDB as a possible suspect? Could it be the Transformer Rectifier Board, even though all voltages check good? I have no idea what is causing the short, as I have ruled out most possibilities. I have traced every bit of wiring associated with the failed lighting and I found nothing: no stray globs of solder, no bare wire touching metal, and no structures in close proximity, which would cause a short. If I keep on replacing things, I might as well make a new, complete machine! I don't have any spare boards, other than what I bought for Xenon and my project Centaur. I have been swapping Alltek boards (MPU and LDB) from Centaur to Xenon, but I keep getting the same results. I will probably end up buying the Weebly boards (MPU, SDB, LDB), to see if those make any difference, since I don't have any OEM stuff.
You must be pulling your hair out at this point!
I'm thinking you have a blown bridge rectifier now since you lost all GI.
I have been using Alltek boards on my restores for more than 10 years and I never had an issue like this, well except for one on a Xenon with an older revision of their SDB board. It was sending higher than normal voltage to the sounds plus board and caused a no sound issue. Other than that, no problems. I have also used Weebly MPU's with no issues. Both brands have excellent CS support so maybe contact Alltek with your problem.
Perhaps post some photos of the suspected GI areas of the lamp insert panel so we can look and compare.
The rectifier board should be your next thing to look at, -54 board. You have 2 GI fuses, 1 for pf and cab, and 1 for the backbox. The fuse clips for these should be replaced with heavy duty, high current upgraded clips as they tarnish from excess heat over time. Run a voltage test of all the test points with all of the right side connectors removed, this will be a "no load" test. Be careful where you touch as there is high voltage there for the displays. If the traces under the board look dark, possibly burnt, then I would replace it with a Weebly. He has a DIY kit for a good price. But you still need to find the short in the backbox in the mean time.