Had my Jurassic Park for 2 weeks now. Wife was playing last night and as the ball enter the T-Rex it just froze. Display went out and all game sounds stopped. GI on and had buzz in speakers. CPU Board had no led lights at all. Swapped out the power supply from my Hook (it is a Rottendog) and JP CPU now has +5v light and PIA Light on all the time. Dino Roar when first turned on and still only hum and GI after that. Read a long post about this from 3 years ago that seemed to go nowhere so need some advice. My first idea is to now swap out the CPU from my Hook. Whilst doing that I broke a pin on the JP ROM. New ROM on the way but am I doing the right thing? I dont want to lunch out the good CPU if there is something else I should look for first. Again, no problems at all before this happened.

So not booting, which I am guessing that is why I have no sound or Display. GI work and audio Hum with new Rottendog power supply and I have +5v light and PIA light solid on CPU Board.

Original Power supply GI work and audio Hum but no lights on CPU Board.

Thanks
Garey

It does not have batteries, has the battery eliminator, Should I remove it?

OK super bowl over now can mess a bit more....

I took the CPU board out of the JP and the Rottendog CPU board out of the Hook. Installed the Hook ROM in the original CPU from JP, installed in machine and Hook works fine with the JP CPU Board. Hook is still running the Rottendog power supply and PPB. What should I try next. I am still waiting on the new JP Rom as the old one has a broken pin and i could not solder an attachment to it. Should I try to put original JP power supply into Hook? PS I also swithced the NVRAM and my Hook scores are still saved.

I just closely inspected the Original JP Power Supply. I can see no burns, leaks, cold solder joints, nothing. I pulled each fuse and tested each one. They all test good with a continuity meter, but when i put them on a bench tester the .5 amp fuse shows no good. Probably some minor continuity but a bad fuse. I replaced all fuses. In doing so one of the fuse holders broke. Replaced it. Put the power supply board into Hook and I get GI and humm but no +5V or any kind of led lights on the CPU Board. Pull it out put back in the Rottendog and perfect machine again.

So, what I think I have learned is that at the very least the Original Power Supply is bad. Obviously the CPU must be good because it works in Hook.

Funny thing is that when I put the Good Components from Hook into the JP I could only Get +5 Volt and PIA Light solid all the time. No Blanking and no Boot. A quick roar from the Trex Audio. Again, I will be getting the ROM for JP in next couple days and can try again with all new Rottendog in the JP transplanted from the Hook.

I at least need a new Power Supply. Could there be anything else that caused the power supply to fail to begin with. Again, this all happened during gameplay when the ball landed on the T-Rex pad. My wife does not remember if the T-Rex moved at all but it froze up before it started its tilt downward or was ejected from pad. Could a T-Rex problem of some sort kill the power supply? Or was it just its time.....

Advice? Experience? Anyone repair power supplies?

So got the JP Rom, installed all Rottendog Boards from Hook into JP and it works great! The Hook is now using the JP CPU Board and awaiting either a repaired Original Power supply board or a new replacement of some sort. So It looks like this all came down to a failure somewhere in the original JP power supply. Having another compatible Data East Machine made this a bit easier but for my blunder of breaking the original JP ROM.

Hope this helps anyone in the future.