Jungle Hunt HELP - smoke

[priglmeier]

Picture?

Got a picture of a Jungle hunt PCB with the JAMMA adapter attached??? Perhaps one shot of the whole this and one of just the wires around the power area.

 

[Dokert]

I honestly don't trust that jamma adapter, no offense, but it is made shitty. One thing is to ensure the pins on the edgeconnector (adaoter) fits the pins inside the jamma harness. Jamma harness connector can have extra space in it where the edge can move inside or not get inserted evenly.

Kevin

When I check voltages on the PCB by the adjuster pots... the VDC pin registers +1.04 VDC and there is another pin that is labeled 13 VDC that registers +10.50 ish.

Your answer is right here... Look closely at the two quotes.

Do you think I should try to crank up the power on the power supply?

HELL NO!

 

[priglmeier]

Your answer is right here... Look closely at the two quotes.



HELL NO!

Nice.

So perhaps a test setup like this may help to solve the problem: I'll redo the power wiring temporarily and then try the PCB.

What is confusing is the adapter shows correct voltages when I check it from the power supply through the pins without the PCB attached. Also, it can't be the edge connector because there is no power on the edge connector and it looks fine. It should be the power connector...

 

[priglmeier]

This thing is F***** up

I re-did the jamma connector with a new finger board. Tested it with no progress.

I re-did the power. Tested it with no progress.

What now!?! IT HAS TO BE THE PCB.

 

[mspaeth]

Here are some images.

wow... that's one seriously shitty looking adapter

 

[priglmeier]

advice

Anyone got some tips on where to go from here? I have quite a few PCBs and I have never had anything like this happen before???

What can I check on the JH PCB? Need someone with a JH PCB to lend me a hand.

 

[InstantArcade]

Just a stab in the dark here, but you might have a shorted cap on your JH board. Have you tried a resistance test across 5v and Gnd on the board? That would be a good way to see if you have a dead short.

 

[priglmeier]

Just a stab in the dark here, but you might have a shorted cap on your JH board. Have you tried a resistance test across 5v and Gnd on the board? That would be a good way to see if you have a dead short.

FROM EARLIER PSOTS -> When I check voltages on the PCB by the volume adjuster pots... the VDC pin registers +1.04 VDC and there is another pin that is labeled 13 VDC that registers +10.50 ish.

There isn't an easy way to check the caps themselves since I can't get to the pins. (see images in this post - flush mount) AND I don't want to leave it on for more than a few seconds hooked up to power and damage the PCB or the power supply.

Thoughts?

 

[mattosborn]

FROM EARLIER PSOTS -> When I check voltages on the PCB by the volume adjuster pots... the VDC pin registers +1.04 VDC and there is another pin that is labeled 13 VDC that registers +10.50 ish.

There isn't an easy way to check the caps themselves since I can't get to the pins. (see images in this post - flush mount) AND I don't want to leave it on for more than a few seconds hooked up to power and damage the PCB or the power supply.

Thoughts?

He's not asking you power up the board.... With the power OFF (board unhooked from your harness/adaptor), check the resistance between the +5V and GND rails. It should not be zero. If it is, do not power up the board again until you find where the short is.

 

[priglmeier]

He's not asking you power up the board.... With the power OFF (board unhooked from your harness/adaptor), check the resistance between the +5V and GND rails. It should not be zero. If it is, do not power up the board again until you find where the short is.

Sure. Where to start? Caps first?

 

[mattosborn]

Sure. Where to start? Caps first?

First you need to measure the resistance between +5V and GND. What is it? That will tell you whether you need to go hunting for a short.
Start by pulling the boardset apart (removing the ribbon cables) and measuring the resistance on each, so you can isolate which one contains the problem. Then remove all the socketed ICs first and see if that clears the short.

 

[priglmeier]

First you need to measure the resistance between +5V and GND. What is it? That will tell you whether you need to go hunting for a short.
Start by pulling the boardset apart (removing the ribbon cables) and measuring the resistance on each, so you can isolate which one contains the problem. Then remove all the socketed ICs first and see if that clears the short.

I found a cap on the bottom board which is not easy to see. Exploded out like a kernel of popcorn. It is capacitor film tdy-14-104 104k50.

Where can I find one easily (locally). Give me a couple sources please.

Oh, and I may need a couple more caps electrolytic 16vb220.

Thanks to all!

 

[priglmeier]

Success!!!!

I went to the local Axman (its a surplus store... very fun) and found the caps I needed for 15 cents each. I replaced the cap and checked through the PCBs.

The test went well. I have video. The PCB definitely needs some RAM or perhaps some new ROMs, as the text is a bit garbled, but it is working now.

Thanks to all who helped out!

PS - I will try to post some more images later.

 

[teckkev]

If game runs fine but some txt is off/backwards, replace the 2 rams on bottom pcb.

Kevin

 

[priglmeier]

If game runs fine but some txt is off/backwards, replace the 2 rams on bottom pcb.

Kevin

Game powers on and yes the text is scrambled. Where do you buy your RAM?
http://www.arcadechips.com/ perhaps???

The game stays in demo mode. The coin and start buttons have no effect. There is no working sound yet either.

I won't complain since I just got the thing up and running. At least it's progress.

 

[teckkev]

I think Riptor has some for sale.

Kevin

 

[priglmeier]

Images

Here are some Images of the exploding capacitor and the Jungle Hunt after it powered on.

 

[priglmeier]

More

Here are some Images of the exploding capacitor and the Jungle Hunt after it powered on.

PCB worked for about an hour before stopping and blowing another cap.

Decided to try shifting around the existing RAM to isolate the issues and to see if I could get it the power on again. Got some cheap caps at ax-man surplus and replaced about 12 caps. The PCB is running better and it is playable with sounds and service buttons working. the coin button will not work properly... anyone got ideas on that issue? For now I'm hooking up the service button to the coin switch.

New RAM is on it's way!

 

[teckkev]

Check ground on the coin mechs. Good test is manually ground the coin1/2 lead to see if it registers.

Kevin

 

[mattosborn]

PCB worked for about an hour before stopping and blowing another cap.

If it keeps blowing caps then you need to take a closer look at your power supply. Are you seeing any AC ripple on your DC outputs?