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[TomT]

I have sent my Celestron Advanced VX mount in for warranty repair (2 yr warranty, purchased July, 2014).  It has never been a good star tracker for photography, star trails have shown up within a couple of seconds of exposure, but I thought it was my problem in not properly balancing or aligning.  More than one service rep suggested the power supply and connector, which I checked as having consistent voltage >12 and a tight enough connector.  But with this "no response 17", and then a "no response 16" showing up on the hand controller without the ability to move the mount in any direction, this may suggest what others have experienced, that this is a "6 wire" generation I mount, whereas the newer "Gen II" mounts have 8 wires going to the motor to carry the current properly, I think.  I will hopefully update this after receiving the mount back.  Celestron did send a free shipping UPS label which is a relief on avoiding that cost.

Update: rec'd it back today, October 29, so it was only gone for a couple of weeks.  The electronics was changed from the plug-in 6 wire connection to an 8 wire connection (22awg? ethernet cord?).  I will now have to test how well it tracks.

Update, 10-31 tracking test:  a bit better on long tracking, but my camera, Olympus E-3 (2007), is not very sensitive and leaves a lot of junk in iso's greater than 100!  There was a sawtooth pattern developing in one shot, which someone suggested is a declination alignment problem.  My north alignment was off when I checked it later, so some settling of the mount takes place.  Folks in a Celestron Advanced VX forum are having good results using a off-axis autoguider, so for another $500, I might do that, an Orion Mini Deluxe Pro.  The camera will need an upgrade as well.

[brucesbau]

Tom,

I get excellent tracking with my Orion SkyView Pro mount, which is very similar to your Celestron Advanced VX mount.  The Az and El drive motors are different between the two mounts (stepper motor vs. dc motor), but that difference should not affect tracking.

The major thing I have noticed to get good tracking is very accurate polar alignment.  When I get aligned within 4-minutes of arc (or better), I can take 5 minute exposures without star trails.

I also use the "hat trick" by holding a black painted cardboard piece in front of the scope when I trip the shutter, then remove it a few seconds later.  The mechanical motion of the shutter in the camera causes "shutter shake", which can make stars into commas.  The hat trick delays the exposure start until the camera quits jiggling.

If I still get star trails, I recheck north alignment.  It is generally the source of the problem.