CP4025 stubborn 50.2 fuser error

[ikorman]

Hello, new to forum here, but far from new to HP LaserJets.  I have a friend with a CP4025 which started throwing a "50.2 fuser error" every time it boots, and unable to print of course.

Things I have replaced so far, done sequentially:

1. fuser

2. main power supply

3. high-voltage power supply RM1-5780

4. upper high-voltage power supply RM1-5781

Last two were done simulataniously, just to avoid taking this beast apart twice.

I am at my wits end.  What could be causing this problem, still?  The only two major board left are the formatter and controller.

Any ideas?  Is there any test  I can try to determine what the curprit is?  Thanks in advance! 

[ikorman]

OMG, I think I know where I goofed:

Looked at the original fuser part number RM1-5550 100V and the one I replaced it with is RM1-5606 200V  !!!

Ordering the right part now.  Duh!