shardian
New member
New pin: Jurassic Park (And a Freddy pin to repair with it)
Just got two more pins Friday. Jurassic Park is mine, and the guy brought up a Freddy for me to repair for him.
First, Freddy: Cosmetically nice. Dead though with junk on the screen. I suspected the battery. First I looked over the boards and then checked the outrageous number of fuses. No one will ever accuse Gottlieb of UNDER-engineering something! Found a fuse blown by the transformer. Replaced it and turned game on - fully functional! There are numerous issues though that will need my attention. It is so much easier to diagnose when the game works though.
Jurassic Park: I knew this one would be a project. The pics showed extensive acid damage on the CPU. The front cabinet panel was trashed. The playfield might have been okay from the pics - hard to tell since the glass was dirty as hell.
Get it in and inspect. The acid damage AND the front panel are worse than the pics showed. Other than the front panel, the cabinet is nice. Upon inspecting the playfield, I was presently surprised. The playfield is nice. I mean N-I-C-E. There is no wear to speak of, not even on the gobble holes. It isn't even really dirty. I could wipe a rag on it and call it a day!
I've been working on the boards and have made some progress. All kinds of stuff locks on and nothing really works. Tons of the crappy fuse holders are broken. Tons of fuses are blown. I replaced one and a bunch of coils locked on, the dinosaur started going up/down, and the shaker locked on.
I've did a quick rebuild around the acid damage. I've replaced a few connectors and headers, etc. Today I bench tested the CPU and the PSU. Low +5, so bad caps on PSU. Only 3.36 volts. That explains everything being dead. Booted with a pc power supply, the board has PIA and +5 led's on with no blanking action. I switched to both test EPROMS, and switched in a spare ram. No difference. I started testing the cpu, and all the sudden the game started trying to boot when I probed pin 39 on the CPU chip. It cycled between blanking and pia led's about 10 times, with the relay kicking each time. Then it shut down to only the +5 led being lit. I got it to do this about 3 times. Bottom line, the acid damage has propably detroyed a trace or twenty. I'm probably going to ship off the cpu board and repair the PSU and PPB myself.
Pics coming later.
Just got two more pins Friday. Jurassic Park is mine, and the guy brought up a Freddy for me to repair for him.
First, Freddy: Cosmetically nice. Dead though with junk on the screen. I suspected the battery. First I looked over the boards and then checked the outrageous number of fuses. No one will ever accuse Gottlieb of UNDER-engineering something! Found a fuse blown by the transformer. Replaced it and turned game on - fully functional! There are numerous issues though that will need my attention. It is so much easier to diagnose when the game works though.
Jurassic Park: I knew this one would be a project. The pics showed extensive acid damage on the CPU. The front cabinet panel was trashed. The playfield might have been okay from the pics - hard to tell since the glass was dirty as hell.
Get it in and inspect. The acid damage AND the front panel are worse than the pics showed. Other than the front panel, the cabinet is nice. Upon inspecting the playfield, I was presently surprised. The playfield is nice. I mean N-I-C-E. There is no wear to speak of, not even on the gobble holes. It isn't even really dirty. I could wipe a rag on it and call it a day!
I've been working on the boards and have made some progress. All kinds of stuff locks on and nothing really works. Tons of the crappy fuse holders are broken. Tons of fuses are blown. I replaced one and a bunch of coils locked on, the dinosaur started going up/down, and the shaker locked on.
I've did a quick rebuild around the acid damage. I've replaced a few connectors and headers, etc. Today I bench tested the CPU and the PSU. Low +5, so bad caps on PSU. Only 3.36 volts. That explains everything being dead. Booted with a pc power supply, the board has PIA and +5 led's on with no blanking action. I switched to both test EPROMS, and switched in a spare ram. No difference. I started testing the cpu, and all the sudden the game started trying to boot when I probed pin 39 on the CPU chip. It cycled between blanking and pia led's about 10 times, with the relay kicking each time. Then it shut down to only the +5 led being lit. I got it to do this about 3 times. Bottom line, the acid damage has propably detroyed a trace or twenty. I'm probably going to ship off the cpu board and repair the PSU and PPB myself.
Pics coming later.