Have a workforce 3530 with a 0x90 error. Says to power down unit and power back up. I have tried:
Power down and up, blowing out unit with air, shaking unit, looking for paper or any foreign object, unplugging from wall - waiting an hour - plugging back in.

It will try to power up, go through some steps, then a high pitch whine - then the error.
The ink tray will move several times - but not very far.

HELP - Getting frustrated! Google has NOTHING on this (that I could find anyhow).
Couldn't even find that code in the manual.....