Meade ETX 105EC 'Runaway' problem

[yoda776]

I recently took my telescope to an astronomy club scope school to see if I can get my scope checked out. The issue is I can perform the two star easy alignment, have checked location details and trained the drive motors and it will not track a star with the Autostar 497 controller. The star is found and then just goes quickly out of view. no sound of motors running. Was running on batteries but now on power and still the same issue.:confused2:

The autostar does respond and get the drives to slew ok. Have also set up in home position in the presence of more experienced astronomers than I and they seem to think the same thing. Runaway problem.

The motors just do not seem to track and was told this is a runaway problem and common to ETX105s. I purchased this one from the US secondhand and not sure it there are any settings I need to be mindful of from the Northern Hemisphere (although have changed the location already).

I realise the firmware appears to be 22e which I have been told is old (and checked think it is up to 43e). I am planning to update the firmware to see if by some remote chance this fixes the problem (seems doubtful).

The only solution I have been told is to take it into the local Telescope store where they can fix the problem. Just hope that is not too expensive. Want to get this little scope running as it is a great scope to view through.

If anyone has any other ideas I would greatly appreciate it.:help:

[brian nordstrom]

:mad2: Yep , try the upgrade , but I wont hold my breath as Meade's (497)software is average at best , sorry .
Next option is de-fork it and mount it on an EQ3 fitted with GOTO , this would be a great set up all round , I think there is one in the classifieds now .
Such a shame as . as you say the optics are first rate in these 105;s
Brian/

[AndrewJ]

Gday Matt

22e is old, but you mentioned playing with power supplies.
The encoders in the scope are illuminated by a variable voltage supply, which can be affected by changing power supply.
There is a function "Calibrate motors" that resets this.
Try that first and see if it helps.

Andrew

[yoda776]

Thank you for the reply. I will have another check of this when I get a moment to see if I can calibrate the motors. I did the train drive motors after the power supply had been changed as the batteries did not last long. Will update firmware when I receive the cable from the US. Other than that it seems I make need to get it repaired.

I might save deforking as a last resort as it is areal shame this is not working properly. :(

[yoda776]

Yeah I am not holding my breath either, but everything is worth a shot. Apparently a fellow in Adelaide can fix it for me, although I have not been told how much. I will enquire and see, but thought it is worth asking here with all of our collective brain power to see if there is anything that can be done beforehand :) Apparently there are a couple of guys that program the Autostar 497s with after market software, so I may give that a try if all else fails as well, especially if you are suggesting the meade autostar 497 software is clunky. Thanks for your comments - might look into those options as well with the EQ3. :thanx:

[AndrewJ]

Gday Matt


Where did you hear that???
There is no third party firmware available to replace the Autostar firmware. There are "patches" available to fix some existing bugs, but anyone can load them, and they dont specifically cover what you are describing.

Based on both axes working manually, and gotos working, i dont suspect there is a "mechanical" problem. Updating to the latest 43Eg firmware ( with patches if you want extended functionality ) should resolve the problem, and if not, at least will load a peek function that allows a bit more diagnostics to be done.

Andrew

[yoda776]

can only presume I must have heard wrong (was at a club meeting) and it must have been the patches. I have the latest autostar firmware file, just need the cable to arrive to apply it. Will go for the patches pending if the firmware upgrade does nothing.

[AndrewJ]

Gday Matt
If you do or dont use the patches, i always recommend using the free StarPatch loader ( instead of Meades ASU ) to do firmware updates
as it is much more robust than ASU and gives better diagnostics.
http://www.stargps.ca/starpatch.htm
All the latest patches are on this site as well
( note buying the GPS lump costs money, but the loader application is freeware )

Andrew ( one of the 2 who write the patches ;-) )

[yoda776]

Nice to meet you Andrew and I suspected from the last post you were probably one of the two who wrote the patches. I appreciate your clarification. I will check out the site and see what I can do - at least what I was told about what must have been the StarPatch loader was true in giving better diagnostics. At the end of the day as long the autostar controller works and telescope behaves I will be happy. Still waiting for Meade cable to arrive. When I try I will let everyone know how I go.

[yoda776]

Just as a follow up I fixed the 'runway' problem with an update to 43E for the Meade ETX 105EC. No other update required. Can hear the motors ticking away while tracking and left it tracking a few stars and the orion nebula and kept it in the field of view almost dead centre (although that would be likely an alignment issue I have to work on with me setting it up and practice makes perfect, or somewhat better :P). Works like a charm now and tracks as it should. It is a great little scope and quite powerful for what I can see out of it.

Cheers for the advice.

Oh and by the way Andrew, looking to get the Star GPS unit with cables for the Orion and Meade.