Mend > Document Laminators

GBC 4250 No Power?

What happened:
Co-worker went to use the rear cutting blade to cut off excess laminate while the machine was in operation (rolling). I happened to be overseeing the project and watched as the unit simply powered down and will not power again. All plastic guards were in place, no sounds when it shut off and no smells.

Background:
This laminator has the feed tray sensor bypassed by the prior owner and we have had it working for about 5 years like that. I also ziptied the safety shield sensor so it was always on so I could open it about half-way during operation so the cams would actually apply more pressure to the heat rollers (which are ancient).

Things I have checked:
Continuity on rear fuse and internal fuse
Continuity/operation of the safety shield switch
Continuity/operation of the on/off switch
As far as I can tell the wiring is in flawless shape--and have checked several for continuity.
The two control boards appear to be in flawless condition--capacitors are good and used a loop to visually check both boards.

I have no idea how to check the heat sensors and/or the heating element, but I am not sure either of those can even cause this issue.

I assume the unit would power even if the motor burned out.

Nick
October 2015

GBC GBC 4250 Office Appliances, Document Laminators Gbc 4250 Power

Hi I service these machines all over the western pa area.

theres a thermal fuse and a sensor transistor located right under the bottom read rubber heat roller.

the transistor goes bad the machine overheats, and the thermal fuse blows.

unplug the machine, remove both side covers, remove the screws so the back grey cover can fold down.

from behind you can see a metal block under the bottom red heat roller.

follow the 2 heavy wires that go to that big metal extrusion.

trace the 2 heavy wires, and jump out bypass the thermal fuse.

now plug in the machine it should power up.

the other possiblity is a bad main switch. but almost all no power machines are from a blown thermal fuse.

if thats the case you will have to replace the transistor on the heat temp board, and the thermal fuse

bob haller service and sales pittsburgh pa 412 366 4906
November 2015