I picked up several machines to start my own collection over the last two years, and am trying to finish my 1979 Hulk. This is a System 1 Gottlieb SS. I waxed, replaced rubbers, bulbs, etc. I removed the onboard niCad battery (no leakage), and created the 4-AA (1 slot with diode) replacement and soldered that in, and did some other maintenance work. It would be all good to go, except for one large issue that popped up:
- I found a broken green wire soldered to the "on" switch underneath, which was a ground downstream and re-soldered that.
- The ground solder on the "TEST" switch on the inside of the coin door was broken. Re-soldering that make it work again to begin with (wouldnt power up before that was fixed)
- The orig owner installed an external "coin" insert button on the outer door for credits.
When I first picked it up, the displays worked, altho they were somewhat dim. When I finished all the bulbs/plastic/waxing/cleaning, etc. the displays were all gone (60v/42v). I have read the system 1 guides twice now, in addition to common issues with displays. Here is what I have covered so far:
- I was sure it was the Power supply board. you could tell the orig owner (who was a pin maint guy before he gave it to a family for it to sit for 7 yrs) did some custom repairs on it, and I was no longer getting juice to the J3 pins. So I purchased a replacement Rottendog power supply sys1 board and installed it. Everything fires up brightly and quickly now on the gen. illum, etc., but still no displays
- I tried (power off first) removing display board cables 1 by 1, to no avail.
- I replaced the 69VAC fuse after the transformer on the bottom board to this power board with the correct 1/4 amp slo blow. No workie. I also verified the integrity of the underside of the fuse holder, block, fuse clips, etc.
- I replaced the J1-J2 cable with an upgrade replacement (unrelated, common issue, just for the heck of it)
- I tested the J3 connection on the power supply board, with the plug unplugged, and power on. The 60v on the positive, and grn pin 5 for the neg as the guides describe. At first, I had 2-8 volts, which quickly dissipated to 0. Since then, I get 0 volts on the 42 or 60v pins.
Obviously at this point I can tell that the power for the displays is not even getting TO the new power supply board, but failing somewhere beneath. I checked the wire plugs from the bottom board to the upper twice. I tried disconnecting the J2? (the one going to the CPU board from the power supply board, before the displays) with the power off, powered on, and tested the pins again to avoid drain, still no juice.
Since the fuse block is not at fault, something below is keeping the power from getting to my new power supply board. I visually and physically checked each wire, solder point, ground, etc. following the path. I am not an extremely experienced electronics engineer however, so I am at a loss on what else to check from the transformer to the power supply board.
Any help would be much appreciated friends. The game plays perfectly in all aspects other than all 5 displays being out. All sound, general illum, coils, mechanical parts, game modes, and additional lights "ball i play" etc. work, so it is very specific to the power that provides the 60v/42v display current. I understand the sys1 schematics fairly well now.