Jurassic Park
Data East, 1993On a 1993 Jurassic Park machine, the wrong solenoids are firing. It Only happens with the computer controlled blue wire solenoids.
I double checked everything is wired up properly.
In the solenoid test:
Left turbo activates right turbo
Right turbo activates left slingshot
Left sling does nothing
Shaker motor activities left turbo.
What's going on? Is it possibly the rom chips degrading?
Quoted from B25MITCH:On a 1993 Jurassic Park machine, the wrong solenoids are firing. It Only happens with the computer controlled blue wire solenoids.
I double checked everything is wired up properly.
In the solenoid test:
Left turbo activates right turbo
Right turbo activates left slingshot
Left sling does nothing
Shaker motor activities left turbo.
What's going on? Is it possibly the rom chips degrading?
Suspect blown fuse on PPB board
Check/replace
s-l1600 (resized).jpgQuoted from B25MITCH:On a 1993 Jurassic Park machine, the wrong solenoids are firing. It Only happens with the computer controlled blue wire solenoids.
I double checked everything is wired up properly.
In the solenoid test:
Left turbo activates right turbo
Right turbo activates left slingshot
Left sling does nothing
Shaker motor activities left turbo.
What's going on? Is it possibly the rom chips degrading?
Let's see, something is clearly messed up with your special switched coils on CN19 of your MPU board.
I highly doubt the ROM is bad, usually when a ROM is bad you just don't boot... Not a transistor issue either, because the circuits are actually engaging... well some of them.
To start, make sure the connector at CN19 is wired correctly.
Following the logic circuit back in the schematics I'm thinking it's something to do with the large 6821 PIA's circled #3. I've seen these socketed often from previous repairs. If they are, you can swap them around to see if odd behavior moves somewhere else, as all 3 of those are identical. #1 and #2 circled don't seem likely bad because of the behavior you mentioned though.
pasted_image (resized).pngpasted_image (resized).pngUpdate, I went to switch the chips as they are socketed, and one of the pins came off. I'm ordering 2 and will update when they arrive.
Quoted from B25MITCH:Update, I went to switch the chips as they are socketed, and one of the pins came off. I'm ordering 2 and will update when they arrive.
Cool, hopefully just popping new ones in solves the problem.
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