I do not know if you can help me..but here goes.
I have a HP Laserjet 4100 mfp. We had a power outage & now the ADF & the whole control panel are dead. You can still print to it? I checked the fuse in the scan unit power supply it seemed OK. I just went for the obvious. I don't want to start tearing the whole thing apart.
Thank you for your time.
Tech Support Answer:
That would be a bad scanner power supply, RG1-4175. These power supplies are known for failing and causing a blank display, and you can still print to the printer