Hi Paul,
>
> About a year ago, every now and then the orange TCU light would flash.
Do you mean, while engine was running ? During cruise, for instance ?
> I'd power cycle and it would go away. Over time it is almost at the
> point that this happens every time. At first I thought it was just
> the waste gate sticking, but after further investigation I realized
> that if the waste was stuck, the servo would move and the cable would
> bow in and out. (Lockwood confirmed this).
Are you sure the servo is so powerful as to overcome any cable binding
or wastegate sticking ?
Have you tried disconnecting the cable at the servo end to observe what
is going on at power on ?
>
> In my case what happens is the the servo just doesn't move. I can
> hear is making the normal "growling" noise, but it doesn't do its
> normal cycle on power up. If I start the engine and power cycle the
> TCU then all is well.
If it growls, then it is trying to do its duty. What prevents it ? Cable
? Wastegate ? Stuck bearings inside ?
By the way, did you install it in the safe environment of the cabin, or
in the engine compartment inferno ? (We chose the cabin for the TCU and
servo).
>
> I asked the Lockwood guys and they think I have a faulty servo. I
> have reseated all of the cables but it didn't make any difference. I
> really don't want to buy a $370 servo just to find out it that its not
> the problem.
>
> The next step is to go buy a servo to prove this theory, but before I
> do I'd be interested in an other ideas.
>
I would first remove it from the airplane, and conduct a close
inspection and some bench tests.
But first, does it work with no cable ?
And what about the TCU connectors cleanliness, condensation, etc...?
BTW, the yellow light (if correctlly wired) might indicate a TCU
malfunction ;-((
Keep us posted,
Best regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr
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