Jurassic Park music cuts out during gameplay

mecha

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when there's a lot of coil action going on, the music will spontaneously quit playing OR the dinosaur growl sound will loop over and over. this pin has a history of issues with the power supply board, so I was wondering does it need a good onceover with the soldering iron? or is this a CPU/ROM board issue instead?

OT: this was previous to my knowledge about connectors burning up and the like on pins, since I'm new to doing any work on them. I fully intend on replacing the PN8 connector (the GI one) with a heat resistant header for good measure.

if anyone's familiar with this problem and knows how to fix it let me know.
 
I did a lot of work on the power supply headers with no change here. considering the speakers sound loud and clear during normal operation I know it's nothing to do with their connectivity.

I pressed all the roms back in with no change. if it helps any I figured out the exact time it happens, and that's during tri-ball.

I've been told if the coils ever go batshit crazy it's cause of a leaking bridge. would the bridge rectifier have anything to do with this, since it's when the game is under heavy load?
 
The Bridge Rectifier could be an issue. If it is only partially bad (i.e. only one of the four diodes bad) the power supply would not have an issue with maintaining the voltage under nominal loading, but during peak loading (i.e. Multiball, both flippers pressed, lots of solenoids firing) it could not provide enough voltage and the drooping voltage could cause the sound to reset. Typically this would cause the main CPU board to reset. Can you monitor the voltage and reset line on the sound card with an oscilloscope during multiball to see what is happening?
 
I'm not sure about the bridges, but can you check the voltages to the board during multiball to see if they drop?
 
I did a lot of work on the power supply headers with no change here. considering the speakers sound loud and clear during normal operation I know it's nothing to do with their connectivity.

I pressed all the roms back in with no change. if it helps any I figured out the exact time it happens, and that's during tri-ball.

I've been told if the coils ever go batshit crazy it's cause of a leaking bridge. would the bridge rectifier have anything to do with this, since it's when the game is under heavy load?

Replace the 47 and 100uf caps on the power supply. That should fix it I think.
 
ok gentlemen, I have deduced that I have a pair of Data East pins with heavy power supply issues! the good news I guess is they're identical hardware...

Jurassic Park voltages:
+5: 5.05
+12: 7.9 (under coil load)-9.0 (normal)
-12: 13.86

that, vs.

Lethal Weapon 3 voltages:
+5: 4.98
+12: 11.31-10.60 (when under coil load)
-12: 15.04

when launching the ball on Jurassic Park then immediately holding both flippers at the same time makes the music reset, and that's when the +12 drops extremely low. the game also makes a hum sound while you hold the flippers down which gradually goes away.

that's pretty much it. am I looking at re-capping both power supplies as well as replacing the bridge rectifiers? I think I saw on a Data East pinball parts site that the bridges are 35W @ 100V, is this correct? any tabs on what I exactly need from like Mouser or something, as well as a cap list?
 
Yes, looks like you have a PS issue. C2 and C7 are the first to suspect on the PS. They are right near the heatsink and get baked.

As for parts, Great Plains Electronics is where I order everything. Ed usually has everything you need, has great prices, and ships quickly.

http://www.greatplainselectronics.com/

It won't hurt to recap everything, but you may only need to replace one or two caps. I did a total recap and rebuild on a DE PS a few months ago. I'll check if I have a list but I don't think I do.

Just curious, did these problems start recently? If so, check your voltage at the wall. Due to the heat, my voltage at my home has dropped about 7 volts vs what I get during the winter. Your voltage may have dropped enough that your problem finally reared its head.
 
happened with the JP awhile ago, when it was still cold out, so I don't suspect it's voltage from the wall. the LW3 was fine when I got it, then started rapidly messing up, the CN8 on the power supply board was nuked, so I had to change all that out on that one.
 
I was trying to do some research on the power supply boards and stumbled upon these aftermarket ones made by Rottendog. anyone familiar with these and are they as good as they're advertised as? my JP board's got a lot of wiring hacks on burnt solder pads for multiple transistors and I was gonna look into getting one of those replacements on ebay, but if this design's better I'll pop for the extra $10.

dps004.jpg


http://www.arcadeshop.com/parts.htm#Pinball Parts
run a Find on Data East Dot Matrix Display Power Supply to find it.

this site design sucks btw, you can't highlight anything or even move up and down without the mouse wheel. wtf
 
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