MP 5500 died while I was working on it

[mikadonovan]

Hi, All. I was working on the finisher sponge rollers on this B246. After I finished, I switched the machine on and 3 seconds later the machine went dead. It is on a dedicated 20amp circuit. After the electrician checked and reset the breaker, I attempted to fire up the machine(all peripherals had already been disconnected) and it immediately popped the breaker again. With the machine still plugged in and power switch off, the breaker was reset and there was a loud pop in the machine, and my customer said she smelled something burning. I removed the rear cover and checked the PS fuses, all good. I have given the part # for the power supply to my boss as I don't know of anything else it could be. Have any of you guys seen this one before on this model?

[skynetto]

Only when one of the fuser lamps short cirtcuit on the chasiss. Main fuse broken and the lights of a whole plain of one hospital goes out.

[techsass]

All of my PSU issues with the Mp5500/6000/6001 series have been with the Controller PSU, not the main PSU.

[nmfaxman]

Check for a pinched wire where you were working on.
A main 24VDC pinched wire will pull enough voltage drop to kill a PS without popping a fuse.

I always tap a metal frame unit when I put it in to make sure I didn't trap a wire to frame.
I would take it apart again and reassemble. Watching where all the wires are routed and not pinched.
Also, was the machine on when you changed the roller?
Just covering all bases.

[slimslob]

Check the power supply for anything such as a paper clip, staple or screw that might be shorting something.

[bob marley]

Check for a pinched wire where you were working on.
A main 24VDC pinched wire will pull enough voltage drop to kill a PS without popping a fuse..

agree with u . had the same problem before

[Herostrat]

In my experience preety much any wire pinched against chasis causes machine eather to blow fuse or generate SC at best,wuldn't be the first time that plastic cower pressed wire so hard against chasis that made isolation to snap and conect.
Blown fuse in power grid happen once to me because of fuser malfunction,short circuit between heating lamp and fuser frame is strong enough to blow grid fuse before the thermofuses react...they are simply slower so if that happens I power machine back on only with front doors open and fuser puled out even after inspecting it.
Now if u have taken of back cower while working on finisher sponges ( I know I like to disassemble finisher cowers...I simply can't fit those 2 little buggers) there is a chance that shift tray lift motor wires got pinched somehow,that motor is powerfull and it's wiring is close to screw hole on cower,in fact I think there is a big bundle of wires going around that conus shaped plastic that get's pressed on metal frame when screwed back in.

[mikadonovan]

Update. The machine has been pulled and I am in the process of finding out what smoked. I'll repost when I get er fixed.

[mikadonovan]

Ok, I found out what smoked. This is a shot from the back of the smaller PWB PCB on the right of the assy. Now I am looking at why. I have found no short as of yet, nor did I find anything behind the board that would have shorted unfortunately. The possibility exists that I could install the new PWB assy and smoke it to the tune of about a grand. It's not just a job, it's an adventure..........

[slimslob]

Ok, I found out what smoked. This is a shot from the back of the smaller PWB PCB on the right of the assy. Now I am looking at why. I have found no short as of yet, nor did I find anything behind the board that would have shorted unfortunately. The possibility exists that I could install the new PWB assy and smoke it to the tune of about a grand. It's not just a job, it's an adventure..........

It looks to me like something actually got under the board and shorted it to the frame/mount plate. As for repair, I would try to bridge the blown trace by soldering a few lengths of wire across the blown area. Leave enough of the trace on the screw hole side of the break to act as a fuse in case there is still a short. If it blows at least it is not the new board. If the machine works, you can either leave it that way or put in the new board. You can also get conductive copper tape to use to bridge the gap. Copper Foil Tape with Conductive Adhesive - 6mm x 15 meter roll ID: 1128 - $5.95 : Adafruit Industries, Unique & fun DIY electronics and kits