autopilot/rigging/prebuy/annual

[cj8vet]

Well the title says it all I am having autopilot(stec 50) problems.avionics guy thinks it is the servo, maule guy thinks it may be the rigging. I just bought the plane and had a prebuy and annual done $4kplus, 1990 mxt-180 I was told the AP wondered a bit. Then it quit working all together.
Wouldn't the tension on the cables have been cked during the prebuy/annual?
avionics guy said the voltage was high on the servos at "start up" he zapped them with some higher voltage and said it barely got it in specs. secondly he is wondering how to get down in the tail to get the servo out? any comments? the shop is a highly respected shop in san antonio
thanks
mark

[maules.com]

Maybe but doubtful on cable tension check at prebuy. Servo clutches could need setting, or if the servo area has been fogged with anticorrosion recently it can affect the servo. To access, use a little mechanic, or remove the flap cable, or remove the last 2 feet of belly fabric by slitting down middle and one forward crosscut. It is easy to join back up with 4 or 6" tape and shrink tight. Test flight can be safely conducted using ductape, or build a metal cover if you want to go there often. Chock the tail up while the mech. is inside.

[Kirk]

My first annual we sent a little guy all the way back to the end of the tail easily by laying down planks on top of the lower tubing.

No big deal at all.

Autopilot trouble shooting is quite an art and if a good shop came up with some odd voltages I'd sure trust their opinion. As to causes, Jeremy might be right about that, you could be lucky enough to get it back into tolerance with a little cleaning/inspection after removal.

Kirk