Z-axis Error

[SAA3840]

I've got a problem I cannot figure out. I keep getting a Z-axis stall, Err E06-0313, Press Stop.
The machine will measure my board just fine and then ask for the
1/16" carving bit. I installed the bit and the machine
ran through all the measurements just fine Except for the "Finding board thickness".
It takes a measurement on the keyboard side, runs across to the swing out plate and then comes back to "Find the board surface". Then it moves to the sliding bar, runs down into the curved hole, comes back up and moves to the other side of the slider. When it comes down
and touches the slider, I get the error message.
What is wrong?
I am running 1.186.10507 firmware,
There are 314hrs on the cut motor, the brushes have been replaced twice, the most recent time was a day or two ago.
It's a "B" machine, serial number starts with B.
I ran a sensor check and with the bit installed,
the reading on the "Z" was:
.176 at the brass wheel,
-2.196 all the way up
-.526 at the slider, touching same
0.208 with the bit touching the round bar the slider slides on.
With NO bit installed and the Z truck all the way down, the reading is 0.764.
I don't know what else I can add.
Can anyone offer a clue as to what's wrong?
I've read all the other threads on "Z" errors and tried all the suggested remedies. There is no longer a whole in the touch-point at the
brass wheel.

Oh, if it matters, I have attached the .mpc for the project I'm trying to carve:

Do you think I need to reset my "Offsets" to the factory settings? The Z truck is not original and I've had it off more than once.

Never mind, I reset the offsets to factory default and then reset the board thickness as per the troubleshooting file.
Still not fixed. For some reason the Z truck comes down on the far side of the slider too hard, like it wants to go deeper. That's when I get the error.

Should the repaired hole in the brass wheel touch point be raised up a bit? Higher than the spring-loaded lever the bit touches?
(Since the loading process gets as far as it does, I'm assuming the flat Z cable is OK.)

[fwharris]

Check to see if the plate that the bit goes down to touch on the keyboard side has a hole in it. If so glue a thin piece of metal or fill hole with JB Weld.

Opps never mind I did not read to the end...

[SAA3840]

OK, the problem has been resolved. Apparently epoxy isn't hard enough. I decided to swap out the tracking roller from my other machine and in the process I noticed that the hole in the spring-loaded lever had returned. I cut out a small piece of sheet metal and epoxied that to the lever and the problem was solved. Carve went fine. That is until I got a "Y" stall. I guess the sawdust built up too much. I vacuumed everything out and put in another project, which just happens to be almost identical to the one I was doing, and it's carving just fine. So I'm once again a happy camper...