M127fw scan fails, WIA shows cancelled by user

[ol69stang]

Whenever I'd order a scan the scanner bar started to move and the touch screen showed "calibrating"; after about 3-5 seconds the home screen would come back up and the scan bar would move back to the left. Scan doctor would report that the scan was canceled by the user, it was not. WIA was red, indicating an error. The drivers and software were uninstalled and reinstalled several times. I even cycled the WIA and associated programs on and off.  I updated the firmware through USB several times.  HP Support was nice enough to go through an exhaustive troubleshooting procedure, with no positive results. One thing we did was to completely reset the unit back to factory startup. Turn the unit off, unplug it. Hold the lower-left corner of the touchscreen and plug it in; turn it on. No change. Support stated that the scanner was broken and I should replace the whole thing. Bummer.

I noticed that when I went to load a page in the Automatic Document Feeder, the touchscreen did not read "document loaded", as in it would continue to read, "ready".  Since now I had two seemingly unrelated problems, I opted to replace the scanner through a third party and try to fix the ADF switch. I turned the unit off and placed a towel on the glass.  I then opened the ADF chute by lifting the thing up.  I sprayed some electrical contact cleaner (available at your local auto parts retailer) on and around the white switch paddle (this tells the ADF that there is a paper loaded in the ADF tray) and  I worked the switch by hand directly a few times,  gave it a few minutes to evaporate, and turned the unit back on. Happily, the touchscreen read that there was a document loaded when I pressed the switch paddle downward; Cool. I noticed also that the light on the scan bar turned on momentarily when I lifted the ADF to expose the scan glass. This was not happening before. Now the scanner is working fine. I'm not sure if this actually fixed the problem, but it might be something to try before you scrap your scanner.