JP PS: using CM3506 instead of CM3501

mecha

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I wanted to know if there's any danger in operating a power supply in a Jurassic Park with a CM3506 bridge rectifier vs. the original CM3501. I found this site at http://kcpins.com/archives/137 and they suggest using a CM3504, but when I was over at AVS last week the tech guy sold me a 3506 as that was all they had in stock.

as it stands right now I think 2N6057 is what's bad and is causing the machine to reset over and over. I installed the CM3506 and at least got the game to boot up again but after it completes that T-rex/diag tests it just resets over and over.

any help preferred. I'm ordering up all the transistors I need between Mouser and Great Plains Electronics (lots of the parts are out of stock on either site)
 
The CM3506 is a 600v bridge. No problem. The CM3504 I recommended in the post you linked to is a 400v bridge. There's no problem going with a beefier part.
 
whoa, that was you. :D

great article btw. the "clean-up" process gets done on a lot of my stuff now before I even work on it. I was entertaining going that route cause the PS board in JP is so hacked, but I made it work. I did a lot of crazy patchwork when I re-capped it last week. the only caps I didn't get were the 4 4700 uf/25v ones, ordered them on mouser this morning though. I tracked down all the transistors, so I'm hoping that fixes it.

what's really bizarre is the GIs didn't work for a really long time and when the PS quit completely they started working again.

stocking up on the same parts to do Lethal Weapon 3 next too.

I'll msg you or something if I happen to run into a snag. thanks for your help.
 
Keep in mind that I was doing a total rebuild on that PS because I didn't have any idea about its past history or what was wrong with it. If you know what is wrong with your PS, I'd just replace what is broken and maybe a few other parts such as C2, a few other electrolytic caps, and maybe the diodes for the HV section.
 
well an update, I was waiting for more parts. I grabbed as much as I could from Great Plains and there was one transistor they didn't have that Mouser did.

I installed a 2N6059 and got the game past diagnostic/T-rex tests. soon as I go to actually play it though, or if you leave it on long enough, the +5 starts going crazy. I had my meter with alligator clips hooked up to all 3 test points. when running fully, the +5 is at 5.05, until it freaks out. sometimes it goes completely dead. at that point I started checking the fuses and they all were all fine.

the +12 is still very low, it reads between 10.3-10.4V, and the -12 is still pushing 14V. these were the voltages I observed last year when the machine still worked.

so to reiterate, I did a complete cap replacement, new 2N6059, new CM3506 bridge rectifier, and I have all the other little transistors too but didn't install them yet. I wasn't sure how much they would have contributed to the voltage issues.

the problem seems to worsen the louder the volume is, and it seemed when I was able to actually start a game that it would freak out with the resets and the fluctuating +5 if you hit the flippers at all.

what do the other 2 bridge rectifiers that are mounted to the wall of the backbox below the PS board do?

EDIT: any thoughts? the upper left 7A SB fuse was one that gave me some trouble with the meter and then eventually it checked out fine. there was a fuse that used to blow every so often before but I can't remember if that was the one or not (when the game still half-ass worked, albeit with the volume real low until it quit booting entirely.) I'm almost leaning towards the 2 diodes by the relay being bad, maybe. would that cause the irregularities with the voltages?
 
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