RZ 220ui Black Masters

[mrfuser]

Okay, it was working fine. Now master is completely black. Checked ribbon cable from master assembly to back of machine, all metered out okay. (pain to check each connection!!)

Any idea what has happened? Thermal Head dead? How do you check?

Thanks

Kelly

[20gaugeO/U]

What's the value of the TPH in protected test mode 1234? Is it black with internal prints like #80 (checkerboard) also. Sounds like a short.

[mrfuser]

Okay, once in a while it works just fine. Makes a nice master and prints great. Then suddenly stops and won't make a good master.
TPH Temp 34
TPH Voltage 1549
Any ideas?
Thanks!
Kelly

[20gaugeO/U]

Does the TPH voltage of 1549 match what is stamped on the TPH? Cut tie wraps and jiggle wires while it makes the master. Intermitten problems can be a pain to locate. Unless you have a spare machine to swap boards or assy's to move the problem. Failing board?