mp c4503 blown fuse fu102

[auburntechnology]

think dc power supply is bad, what made it go bad?

customer said it was tripping their breaker in the panel box.
when i got there, the fu102 was blown.
replaced fuse.
i disconnected the dc power outputs on dc controller and still trips breaker.
bad dc psu?
i have one on the way to replace later today.
i disconnected to dc psu from the ac psu and it does not trip breaker.
hate to put in a board and have it get fried

[fshead]

think dc power supply is bad, what made it go bad?

customer said it was tripping their breaker in the panel box.
when i got there, the fu102 was blown.
replaced fuse.
i disconnected the dc power outputs on dc controller and still trips breaker.
bad dc psu?
i have one on the way to replace later today.
i disconnected to dc psu from the ac psu and it does not trip breaker.
hate to put in a board and have it get fried

is that machine on its own breaker?
Sometimes these customers think they can run a copier,a paper shredder,and coffee maker all on one 15 amp breaker...
If the machine kept loosing power via breaker in panel I could see that killing a power supply

[FrohnB]

Did you replace anything or do any kind of service on the machine before it started doing this? Have seen where wires don't get re-connected and will touch the frame and cause a breaker to trip.
How's your fuser looking? Have you tried a different fuser? In my experience, it seems the fuser is usually the culprit.
Have you tested customers outlet? Is it grounded? Do they have a bunch of other things plugged into that circuit (mentioned above; Fridge/ shredder/ etc.).
Is it plugged into a surge protector or power strip?

[Codex]

Had some similar issue on a Mpc4502..... Turned out to be a fried polygon mirror motor that fries also a fuse on the bicu board...

Inviato dal mio SM-G935F utilizzando Tapatalk

[slimslob]

In almost every case I have heard of where the breaker keeps getting tripped some employee has an electric space heater plugged in on the same circuit. Ask around to see if anyone is complaining about his or her heater constantly turning off.

[auburntechnology]

thanks
no other work was done to the machine in past 6 months, just a transfer belt then.
nothing else on the circuit in the customer building, so i am told they checked.
the circuit breaker trips if all of the output connectors from the dc power supply are disconnected.
no power strip.
i removed the fuser from the machine when i tried it the first time.
they repair cranes so they have to have good clean power , they told me.
so it must be true.
i did not find why fu102 was blown on the ac board.

but i did but put in the replacement dc psu and machine works , sounds good.
power cycled a few times.

i just would like to know what made the board short out.
no screws behind it.

[davel]

PSU probably made in china to lowest specifications.

[anothertech]

nothing else on the circuit in the customer building, so i am told they checked.

they have to have good clean power , they told me. so it must be true.

Now that's a quote
Hahahaha.

[Oze]

I had this last month.
Brand new IM C300 has been in for a week and their onsite electrician decided to change relays in their mains power box with the power turned on
You're on the right track with the dc power supply theory because in MY case they damaged the bridge relay on the dc pcb.
The flow of power goes from the AC board to the DC board THEN back to the AC.
The DC board mostly just looks after the Fuser.
So when the power came back on onsite the surge went from the AC straight to the DC...fried the bridge relay and arced back to the AC taking out the glass fuses (they did their job).
I replaced the AC board originally and the lights in the building dimmed and the fuse on the AC board popped (repairable luckily).
I did this twice to confirm then replaced the DC pcb and all good.

[anothertech]

I had this last month.
Brand new IM C300 has been in for a week and their onsite electrician decided to change relays in their mains power box with the power turned on
You're on the right track with the dc power supply theory because in MY case they damaged the bridge relay on the dc pcb.
The flow of power goes from the AC board to the DC board THEN back to the AC.
The DC board mostly just looks after the Fuser.
So when the power came back on onsite the surge went from the AC straight to the DC...fried the bridge relay and arced back to the AC taking out the glass fuses (they did their job).
I replaced the AC board originally and the lights in the building dimmed and the fuse on the AC board popped (repairable luckily).
I did this twice to confirm then replaced the DC pcb and all good.

A good surge suppressor might have prevented that problem.