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DE JP. Sometimes takes a few minutes to boot. 5V?

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lozzauk

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Joined
Aug 28, 2023
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Hi All,

Our Data East Jurassic Park sometimes takes ages to boot (well a couple of minutes) and when it's hanging we get the following symptoms

5v on
PIA on
Blanking off

Screen on but nothing from the MPU.

This will then sort itself out and start booting but sometimes with corrupted sound during boot.

The game will then play perfectly for as long as we play it (even some hours) If the game is turned off and back on it always boots quickly, with the correct LED sequence, sounds etc.

I did check the PIA chip and it is seated properly etc. The symptoms make me wonder if there's a cap going bad (or we have a dry solder joint somewhere) What's the easiest way to check? See if the 5v rail is actually 5v and has no ripple on it?

The power board is all original as far as I know.
 
Fantazia2 said:
I saw something recently that showed using a multi-meter on AC voltage mode to check ripple on DC voltages.

I think the number it showed was the ripple amount, i.e. if it was 0 then no ripple.

Something like this. - https://sciencing.com/test-crystal-oscillators-8728348.html
Click to expand...

Yes. Measuring DC voltage on an AC setting on a multimeter should give a ripple reading.

I think the question I'm asking is it likely this is the cause of the symptoms I'm seeing? C2 will be 31 years old now in fairness. It looks OK (as in it hasn't leaked) but who knows what its capacitance actually is.
 
lozzauk said:
C2 will be 31 years old now in fairness. It looks OK (as in it hasn't leaked) but who knows what its capacitance actually is.
Click to expand...

You need to take it off the board (as in de-solder) to see if it's leaked. May as well replace it for peace of mind if nothing else, who knows it may even fix your problem...
 
Moonraker said:
You need to take it off the board (as in de-solder) to see if it's leaked. May as well replace it for peace of mind if nothing else, who knows it may even fix your problem...
Click to expand...

Thanks. I had a random event of the game going into the menu and going through it during a game (as if I was hitting buttons inside the coin door) Still did it even with the playfield disconnected.

Typical after I post once booted it's been fine.

Anyway took the PIA back out of the socket and think the socket has lost some spring tension on the socket that takes the DIP. Carefully put the socketed pins back inline, reseated the chip and hey presto.. instant boot up (even after leaving the game for a good hour or so) and plays perfectly.

I'll keep an eye on it. If I take the power board off I'll replace the fuse clips too as they are not great on these boards!

Cheers for the help.
 
Not uncommon for the sockets to crap out - would change it for a machined one.
 
Thanks.

I actually think there's two separate issues here. Even the DMD (pin2dmd so that's 5v?) took ages to come on. Totally blank other than the GI.

So I probably need to look at the power board as it does sound like it is starting to crap out.

Measured a very wobbly 5v test point. Seemed to be all over from 1.7v-3.7v then suddenly 4.6v stable and the game boots. What's likely causing this? C2? Corroded trace under C2?

Job for the weekend I think.
 
Last edited:
Check if anything has corroded around it, especially through hole connectivity. Don’t expect problems there though as it stabilizes. Next thing to check/change is TR5. Have a look if that gets a stable 12V from bridge rectifier DB1. Replace with 2N6059 if toast. I think there is a 5V regulator downstream of TR5 which could also be damaged.
 
Connectors and fuse holders are also always suspect on DE games - don’t think that is your problem though as it works fine after a while.
 
Does that look like capacitor residue under C2? Difficult to see but I think that has to be the prime suspect.

Not really understanding why after the game has booted any subsequent boots are instantaneous until the game has been left off for a few hours. Unless it's just because the board gets warm and it's enough to let it soldier on.

Connectors and fuse holders in this game are OK except for the GI on the PPB, which works (game is LED so no longer gets hot)
 

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Paul said:
Certainly looks like it. No proper way to tell though short of removing it and taking a look...
Click to expand...

Thanks.
My symptoms sound very similar to

Data East Jurassic Park won't boot up

Hi guys, I'm new here and hoping I've found the best place for some help with my machine please? I wonder if you could help me and point me in the right direction to diagnose a fault with my Data East Jurassic Park machine, it started not booting up on power up, I just get a click sound, lamps...
www.pinballinfo.com

Which also turned out to be C2. I'll pull the power board, give it a once over and clean it up.
 
lozzauk said:
Thanks.
My symptoms sound very similar to

Data East Jurassic Park won't boot up

Hi guys, I'm new here and hoping I've found the best place for some help with my machine please? I wonder if you could help me and point me in the right direction to diagnose a fault with my Data East Jurassic Park machine, it started not booting up on power up, I just get a click sound, lamps...
www.pinballinfo.com

Which also turned out to be C2. I'll pull the power board, give it a once over and clean it up.
Click to expand...
And if you are going to pull it, no harm in replacing it whilst you are there anyway :)
 
Paul said:
And if you are going to pull it, no harm in replacing it whilst you are there anyway :)
Click to expand...

Of course. It'll be replaced once the board is cleaned up underneath it.

I'll measure the capacitance of the old one too just for a laugh.

Will update this post once it's done but might not have chance for a few days.
 
Moonraker said:
If C2 is the top most capacitor, then, yes it is.
Click to expand...

Thanks. I'm convinced it's leaked. Can always bridge onto the diode leg on the bottom of the board if it's ruined the trace and the plated through hole.

Need to source a capacitor. Noticed pinparts does them and have a switch that's not great so will order at the same time.

Is it worth recapping any other caps on the board? C2 sits very close to the heatsink which I guess doesn't help.
 
lozzauk said:
Is it worth recapping any other caps on the board? C2 sits very close to the heatsink which I guess doesn't help.
Click to expand...

A few years ago I would have said just replace that one, nowadays I have a better stock of capacitors, and more of them are reaching the end of their life I tend to swap all of them. I should also mention that capacitor prices have been going up a lot recently and will only continue going one way.
 
Also, shipping is going to be the expensive bit if you buy reputable (RS, Mouser), so get the lot.
 
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