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Jpm power supply help please


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#1 mrrix

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Posted 04 April 2019 - 03:53 pm

Grey power supply 50v 10a fuse blew so I thought easy replacement but even with power supply out the machine and nothing plugged in to it it keeps instantly blowing a fuse! Is it shot or is there anything I can check myself or do I get it repaired or wait for one to maybe appear on eBay? Any help appreciated

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#2 richy1976

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Posted 04 April 2019 - 04:36 pm

It's normally triacs on the 50v line.
Payouts.

#3 Mavroz

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Posted 05 April 2019 - 07:54 am

Open up and see if any of the capacitors on the pcb are damaged / split / bulging.

#4 mrrix

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Posted 05 April 2019 - 08:04 am

It's normally triacs on the 50v line.
Payouts.

The lights were "surging / slightly flickering" before the fuse blew, ever so slightly but was noticeable but by the time i was going to look into it the fuse blew and i lost all lights. Machine still works except for the lights although i haven't tried to collect any coinage so its possible this caused the psu problem in the first place. Come to think of it i did have a couple payout errors in the past so maybe this was the first sign that i missed



#5 mrrix

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Posted 05 April 2019 - 08:07 am

Open up and see if any of the capacitors on the pcb are damaged / split / bulging.

I did have a look and they all looked ok, i didnt want to mess too much but multi meter on them one of them was giving no reading so could this mean its not storing any voltage? Couldnt see any damage to the board either, im no expert but it all looked clean (for its age) and no signs of damage. In a way i wish one was bulging so i could easily pinpoint it! If i took it to a electrical guy would it be an easy fix do you think?



#6 richy1976

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Posted 05 April 2019 - 08:25 am

I changed the 3 caps in my mpu4 myself, it's not that hard to do yourself.
Don't forget they are over 20 years old.

Edited by richy1976, 05 April 2019 - 08:25 am.


#7 mrrix

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Posted 05 April 2019 - 08:54 am

I changed the 3 caps in my mpu4 myself, it's not that hard to do yourself.
Don't forget they are over 20 years old.

Yes very true! I am ok with a soldering iron and would like to do it myself if possible so will double check tonight, have another good look at them and do some homework on how to tell if they are functioning or bad. Would you say a bad capacitor = blown fuse?



#8 Mavroz

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Posted 05 April 2019 - 11:11 am

Bad caps could blow a fuse especially if your lamps were flickering. Quite possibly a supply issue. Regulators etc also.

Not saying it is this but it is where I would start.

You will not check a capacitor with a meter unless you have a meter with a capacitance range and you have removed the capacitor from the circuit or at least one leg.

#9 mrrix

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Posted 05 April 2019 - 12:47 pm

Bad caps could blow a fuse especially if your lamps were flickering. Quite possibly a supply issue. Regulators etc also.

Not saying it is this but it is where I would start.

You will not check a capacitor with a meter unless you have a meter with a capacitance range and you have removed the capacitor from the circuit or at least one leg.

Thanks, really appreciate the help, i think i will remove and replace them and go from there!



#10 mrrix

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Posted 12 April 2019 - 07:19 am

Thanks, really appreciate the help, i think i will remove and replace them and go from there!

Little update, i checked the capacitors again and found one which looked bulged at the top, traced it back to the 50v supply so thought i had nailed it. New capacitor arrived and replaced, but same issue. I will now continue and replace all the other capacitors and hope this fixes the issue. Gutted as was so confident that one capacitor would have fixed it at least temporarily until i replaced the others but no....






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