Hello pinheads, I am working on a friend's TOM that has been in storage for about ten years.
The trap door is reading 65v all the time and it heats up. To me, this reads as the hi voltage used to surge the door up, yet it barely holds the door up if I manually pull it up. Seems to be the hold voltage, but it reads high?
The strange thing is that it works sometimes, stays up permanently sometimes, and won't pop up at all sometimes. The problem appears to be twofold: the coil has constant voltage and the bracket has been repaired at the bottom end.
What has been done before:
The previous tech guy put a new coil in and repaired the bracket. It looks like he gave up after that.
What I have done
1. I have read every post on the internet about the trap door. I understand that the positioning of the coil pin can cause malfunction. I have adjusted the bracket (via a fabricated metal stop with rubber stopper) to deal with this issue.
2. I have checked the transistors and diodes (on board) correlating with the high and low voltage. They test fine when compared to other transistors/diodes around them.
3. I have tested the new coil and the old coil for resistance. Both test fine.
4. I have followed all wires to the coils, searching for shorts etc. All looks good.
To me, the voltage is the major problem here. After I get that fixed, it will likely be a case of fidgeting with the bracket length to find the sweet spot.
I thought this machine was going to take me a couple hours to shop, but this trap door is a PAIN IN THE ASS! I guess that's pinball...
Thanks in advance for any help you might be able to offer.