castile not feeding

Quadra-fire Castile problem. Auger will not work, doesn’t feed pellets. It started making a screeching sound when feeding, so I turned it off and let it cool down. Cleaned everything, even pulled the motor/auger out.

Exhaust blower motor blows, ignitor gets hot, and red call light is lit.
Thermocouple is adjusted right.
Jumped the auger motor with 110 volts, and it works.
Door gasket is tight, dollar bill gets stuck when closed.
Vacuum tube is clear.
I put a voltmeter on lots of wires/connections, the service manuals just say to check for power, not how much power should be present. Measurements ranged from 4 to 83 volts.
Removed cap from clean out tee, still doesn’t work (to see if chimney was blocked).
There is no increase in voltage to the auger motor when I push the reset button.

Does anybody know about the error codes? It flashes blue 4 times in a row, six or seven times when plugged in. I can’t remember what it flashed when working.

Thanks for any help!

Figured out the problem.

The vacuum switch is bad. It's basically a hollow metal brick, but is has a plastic block that 2 wires connect to. The plastic block is loose, and has to be in just the right position for the switch to work (and make the auger turn).

I realized this this after spending about 6 hours of testing/cleaning/fiddling with every single possible part. New vacuum switch ordered, cost $60 (not in stock at the nearest dealer an hour away). At least I didn't have to pay $75 an hour for a tech to try to figure it out.