34 replies to this topic

[ryanr256]

I recently acquired an ETX-125PE. It did not come with an Autostar. I found one on ebay for a good price. It arrives and, of course, it has a dead screen. I order a replacement screen and it should be here within a week.

In the meantime, I bought another Autostar from the classifieds. It arrives and it's functional.

I update the firmware. I do an automatic alignment and it goes through the motions to find north, level and tilt. After that it chooses Sirius as the first alignment star.

The scope starts to point at the floor. (!)

I turn it off and reposition the scope to the auto alignment home. Start the automatic alignment again and Sirius is the first alignment star. This time the scope tries to go past zenith in locating Sirius.

I try a couple more times and the behavior is even more erratic.

I do have an Autostar from an ETX-105 so I try that. No issues. Sirius and Rigel as alignment stars and a goto to Jupiter works as expected.

I plug the new Autostar back in and experience the same erratic behavior.

The difference is that the problematic one has "ETX Autostar" on it and the one that functions just has "Autostar" on it.

Any ideas what the issue could be? Bad ROM? Bad RAM? Not enough RAM?

Thanks.

[deSitter]

I recently acquired an ETX-125PE. It did not come with an Autostar. I found one on ebay for a good price. It arrives and, of course, it has a dead screen. I order a replacement screen and it should be here within a week.

In the meantime, I bought another Autostar from the classifieds. It arrives and it's functional.

I update the firmware. I do an automatic alignment and it goes through the motions to find north, level and tilt. After that it chooses Sirius as the first alignment star.

The scope starts to point at the floor. (!)

I turn it off and reposition the scope to the auto alignment home. Start the automatic alignment again and Sirius is the first alignment star. This time the scope tries to go past zenith in locating Sirius.

I try a couple more times and the behavior is even more erratic.

I do have an Autostar from an ETX-105 so I try that. No issues. Sirius and Rigel as alignment stars and a goto to Jupiter works as expected.

I plug the new Autostar back in and experience the same erratic behavior.

The difference is that the problematic one has "ETX Autostar" on it and the one that functions just has "Autostar" on it.

Any ideas what the issue could be? Bad ROM? Bad RAM? Not enough RAM?

Thanks.

The ETX scopes were I think the first ones with an Autostar 495/7. The ETX means only that. The device is the same. The 495 and 497 differ in the amount of flash memory, but are functionally identical otherwise.

 

Such problems as you describe imply a bad connection of the cable to the device. Take a jeweler's screwdriver and scrape along the exposed connectors in socket to remove oxidation. You can buy DeOxit electronics cleaner to help with this process. Under magnification (use an eyepiece with the barrel removed), examine the spring loaded contacts to ensure that they are well seated in their grooves and evenly spaced in both separation and height.

 

I assume you've checked the firmware and telescope type and all that. You should be on version 43E.

 

-drl

Edited by deSitter, 19 March 2025 - 08:40 PM.

[OzAndrewJ]

Gday RyanR

The encoders in the ETX use an open vane disk with an IR led / receiver.

The voltage to the LED is adjusted by the calibrate routine and then stored in the handset.

On booting, the handset writes the stored data to the motor card

so if its wrong, the encoder feedback wont work

Soooo

Plug in the dodgy handset and do a "motor calibrate" to reset the value

See what happens.

Andrew Johansen Melbourne Australia

[ryanr256]

Cleaned the contacts and did a calibration.

No change.

I also verified the location and time are correct.

[OzAndrewJ]

Gday Ryan

I assume this is the second handset where you can read the screen????

If so, how did you update the firmware and what to???

Does it have the correct location ( ie longitude sign )  and time selected??

ie How did you verify these?????

ie if it can find North and Level, it has an LNT ( which also has an inbuilt clock )

so if that is wrong,anything could happen.

 

Andrew Johansen Melbourne Australia

Edited by OzAndrewJ, 19 March 2025 - 10:03 PM.

[Thrifty1]

First thing is to use a good power source. Either brand new AA batteries or a good external power source.

Have you tried resetting the AutoStar? I would reset it which will then do a calibration upon restarting (moves the motors slightly each way). Do a Train Drives during the day on a distant land object.

Then be sure you have the correct location set up and mount set to Alt-Az.


Finally, do a 2-star manual alignment to bypass the automatic alignment using the LNT module to see if that is causing alignment problems.

Edited by Thrifty1, 20 March 2025 - 05:43 AM.

[ryanr256]

The screen works on both.

 

One controller works perfectly and the other is wonky.

 

I've done numerous resets, calibrations, prayers, etc. without success. Sometimes it thinks Sirius is past zenith and other times it think it's in the southern hemisphere.

 

My third Autostar has a bad screen. My next plan of action is to take the screen out of the wonky one and put it in the third Autostar and see how that one behaves.

 

Edit to add - both Autostars have been updated to 43G.

Edited by ryanr256, 20 March 2025 - 08:30 AM.

[DAVIDG]

  I would double check that the Autostar is reading the encoders correctly.  Hold the MODE key down for a few seconds and release it  and that will put you in a menu were you can read the position of the scope. In the Alt/Az readout mode slew the scope at least 45 degree in the both axis and see if the position on the Autostar agrees to at least a degree to that on the analog circles.

  If the encoders are reading correct, even thou you checked the long, lat. and time I would  look at them again. Is Daylight savings time turned on ? What is the UT offset for the location you are using ?  If the sign is off,  on that, that will cause the pointing to behave like you are seeing and then same is true if the sign for  the longitude is wrong. 

 

            - Dave 

[ryanr256]

  I would double check that the Autostar is reading the encoders correctly.  Hold the MODE key down for a few seconds and release it  and that will put you in a menu were you can read the position of the scope. In the Alt/Az readout mode slew the scope at least 45 degree in the both axis and see if the position on the Autostar agrees to at least a degree to that on the analog circles.

  If the encoders are reading correct, even thou you checked the long, lat. and time I would  look at them again. Is Daylight savings time turned on ? What is the UT offset for the location you are using ?  If the sign is off,  on that, that will cause the pointing to behave like you are seeing and then same is true if the sign for  the longitude is wrong. 

 

            - Dave 

 

 

I will do this when I get home tonight.

 

What confuses me is that the behavior isn't consistent. If it always goes the same direction/location when slewing to Sirius, I would think bad configuration. But, I will get different behaviors every time I do an alignment.

 

For example, I will do a motor calibrate, then an automatic alignment. It goes through all the positioning steps and then starts moving straight up, attempting to go past zenith to locate Sirius. I turn it off  repostion it to the automatic alignment home position and try again.

 

This time it works perfectly. No issues. I turn it off and reposition  then try another automatic alignment and the thing thinks Sirius is on the floor.

 

But, I switch to a different Autostar and there's no issues at all. That tells me the problem is in the controller.

[deSitter]

I will do this when I get home tonight.

 

What confuses me is that the behavior isn't consistent. If it always goes the same direction/location when slewing to Sirius, I would think bad configuration. But, I will get different behaviors every time I do an alignment.

 

For example, I will do a motor calibrate, then an automatic alignment. It goes through all the positioning steps and then starts moving straight up, attempting to go past zenith to locate Sirius. I turn it off  repostion it to the automatic alignment home position and try again.

 

This time it works perfectly. No issues. I turn it off and reposition  then try another automatic alignment and the thing thinks Sirius is on the floor.

 

But, I switch to a different Autostar and there's no issues at all. That tells me the problem is in the controller.

You have the Premier edition - I thought that needed a higher version of the firmware than 43E, to handle the LNT module. What is your firmware? Is telescope type set to ETX125 PE?

 

I have an LXD75, a DS2000 Gen 2, an ETX-90EC and an ETX-105EC. They all work with any of my Autostars, including an ETX Autostar, a 24-pin display Autostar, and a 14-pin display Autostar.

 

Are you in EQ or Alt-Az mode?

 

-drl

[DAVIDG]

 If you can slew the telescope with the Autostar and it doesn't run away and moves smoothly in both directions  that would indicate  it is sending out the correct motor control commands so the basic control system is working. 

  If that is the case then  that points to an  issue with the pointing model and too me the data it needs to correctly point the scope.

 When I have had similar issues with the scope pointing in the wrong direction it has been because I had the sign of the longitude or my time zone setting wrong.  A possible  reason why the pointing is not consistent is the data is wrong and  it tries to calculate a path as to not hit the stops or do a cord wrap and difference in time would result in a different path. 

Another test is to set the time and see after an some period the time is still correct.  Did you use StarPatch to update the Autostars or the Meade software ? If you used the Meade software I don't believe it does a check to confirm what was written to memory is correct while StarPatch does so it possible there is bad memory location. 

 

                - Dave 

[Rod Parker]

Not sure this would apply to your scope or not, but I had a similar pointing-at-the-ground issue with my LX200GPS.  It turned out to be the "GPS rollover bug" which resets your scope age to zero after 1024 weeks.  There is a patch available for it--I think the name of the patch is PatchLX42ggv21.spf but I'm not 100% sure.  It's been quite a while since this happened to me.  I hope this at least provides some new leads worth running down.

[OzAndrewJ]

Gday ryanr

The erratic behaviour screams of an encoder feedback loop problem

but if the base works properly with one handset but not the other

then the general reason is the motor calibrate setting.

Having re done that, it sounds like an intermittent connection on the cable

( ie the pins inside the 8pin hbx port )

As you have updated to 43G, you can also use my PEC editor

https://groups.io/g/...ope5002beta.zip

It has diagnostic tools so we can read out the internal settings

and it also has a remote handset.

The handset wont help with a cable error, but it wil bypass the keyboard

( in case there is muck on some keys causing intermittent errors )

Andrew Johansen Melbourne Australia

[deSitter]

Gday ryanr

The erratic behaviour screams of an encoder feedback loop problem

but if the base works properly with one handset but not the other

then the general reason is the motor calibrate setting.

Having re done that, it sounds like an intermittent connection on the cable

( ie the pins inside the 8pin hbx port )

As you have updated to 43G, you can also use my PEC editor

https://groups.io/g/...ope5002beta.zip

It has diagnostic tools so we can read out the internal settings

and it also has a remote handset.

The handset wont help with a cable error, but it wil bypass the keyboard

( in case there is muck on some keys causing intermittent errors )

Andrew Johansen Melbourne Australia

The delicate spring contacts in the sockets can get wonky.

 

-drl

[ryanr256]

I appreciate all the responses. Thanks!

 

The two Autostars I have been working with have the Build43Eg.rom files installed and have been patched with the Patch43GL.spf file. All updating/patching has been done with StarPatch.

 

I've tried 2 different cords with the handsets.

I've cleaned the contacts and ensured the pins are not damaged.

The firmware recognizes the PE as a PE. After booting it gets the time and goes straight to the Automatic Alignment option in the Align menu.

The Patch43GL fixes the GPS rollover bug.

I am using the AC brick for power.

 

None of the above has changed the behavior.

 

I did DavidG's suggestion of checking the RA and Dec values as the scope slews around. The numbers increase or decrease without any obvious errors.

 

I've taken the screen out of the wonky controller and put it in the one I have that has a bad screen. I am in the process of updating the firmware from 25Ea to 43Eg using StarPatch. Once that update completes, I will apply the Patch43GM.spf and test that Autostar.

 

 

 

Edit to add:

 

The updates completed successfully.

 

The first test worked as expected. After the LNT procedures, the 'scope slewed to Sirius and Rigel and the alignment completed successfully. I then did a goto to Jupiter and everything worked. It's currently tracking Jupiter. I will let that go for a while and then I will do a Park.

Edited by ryanr256, 20 March 2025 - 07:15 PM.

[deSitter]

I appreciate all the responses. Thanks!

 

The two Autostars I have been working with have the Build43Eg.rom files installed and have been patched with the Patch43GL.spf file. All updating/patching has been done with StarPatch.

 

I've tried 2 different cords with the handsets.

I've cleaned the contacts and ensured the pins are not damaged.

The firmware recognizes the PE as a PE. After booting it gets the time and goes straight to the Automatic Alignment option in the Align menu.

The Patch43GL fixes the GPS rollover bug.

I am using the AC brick for power.

 

None of the above has changed the behavior.

 

I did DavidG's suggestion of checking the RA and Dec values as the scope slews around. The numbers increase or decrease without any obvious errors.

 

I've taken the screen out of the wonky controller and put it in the one I have that has a bad screen. I am in the process of updating the firmware from 25Ea to 43Eg using StarPatch. Once that update completes, I will apply the Patch43GM.spf and test that Autostar.

 

 

 

Edit to add:

 

The updates completed successfully.

 

The first test worked as expected. After the LNT procedures, the 'scope slewed to Sirius and Rigel and the alignment completed successfully. I then did a goto to Jupiter and everything worked. It's currently tracking Jupiter. I will let that go for a while and then I will do a Park.

 

That's happy news

 

-drl

[ryanr256]

That's happy news

 

-drl

 

Yes, it is. I still have to figure out what's wrong with the wonky one. At least I have 2 functioning controllers now. I'll probably go ahead and order another display just to have on hand in case I need it.

 

I have a replacement display coming Saturday. I will put that in the wonky Autostar and continue troubleshooting it. The good news from all of this is I believe I've thoroughly tested the drives on the base and haven't experienced any issues.

[OzAndrewJ]

Gday ryanr

If you are going to keep playing with the wonky controller, spend $15 on a logic analyser and clips

You can fit these to the comms lines and then start the mount and try things.

It will log everything going on ( for several minutes if reqd )

so you can see where it might be misbehaving by analysing thetraffic.

Andrew Johansen Melbourne Australia

[ryanr256]

A new screen arrived yesterday (Mon) and I installed it today (Tue). No issues peeling the foil off the back. It doesn't change the behavior of the controller though. 

 

I did experiment with the RA and DEC values compared to the setting circles. The values track the numbers on the circles. But, one thing I noticed was that if I move using the DEC buttons, the RA value changes also and vice versa

 

I will pick up a logic analyzer and start looking at the comms.

 

The good thing is I have a working Autostar for the 105 and 125PE. I just have to figure out what is going on with this one. After I fix it, I will have a spare.

[OzAndrewJ]

Gday ryanr

It doesn't change the behavior of the controller though.

But the screen does work properly?????

ie the handset is not having a problem there.

 

I did experiment with the RA and DEC values compared to the setting circles. The values track the numbers on the circles. But, one thing I noticed was that if I move using the DEC buttons, the RA value changes also and vice versa

You are doing something wrong, as it should be the AltAz screen you watch.

You must set the mount as "AltAz mode" and reboot.

In this case, no motors start

Now get to the alternate menus and go to the Alt/Az screen, not RA/DEC

Now slew say 90deg in each axis and note the handset values of before and after.

Do they match, or does the handset under report the distance moved.

Andrew Johansen Melbourne Australia

[ryanr256]

Gday ryanr

But the screen does work properly?????

ie the handset is not having a problem there.

 

You are doing something wrong, as it should be the AltAz screen you watch.

You must set the mount as "AltAz mode" and reboot.

In this case, no motors start

Now get to the alternate menus and go to the Alt/Az screen, not RA/DEC

Now slew say 90deg in each axis and note the handset values of before and after.

Do they match, or does the handset under report the distance moved.

Andrew Johansen Melbourne Australia

 

 

The replacement screen works great. Even better after adjusting the contrast and brightness.

 

And, yes, I was doing it wrong. My bad. I will correct my error and redo the test.

[ryanr256]

I had to suspend this adventure for a while but I was able to pick it up again last night.

I grab the good Autostar I have to compare settings against the one that is behaving badly.

And, guess what? Yep, it now has a bad screen. Dang it. Thankfully it has the 24 pin display. I ordered a couple and they should be here shortly.

Oh well.

[ryanr256]

This is interesting. I received and installed the replacement screen for the wonky Autostar yesterday (Sat.). I downgraded the firmware to Build43Ec with no updates.

Attempted an Automatic Alignment and the same results. The 'scope either points to the ground, or tries to go past zenith while slewing.

Here's the interesting part. If I do a Two Star Alignment and choose the same stars as the Automatic Alignment, everything works as expected. I try an Auto again and I get the wonky behavior.

I haven't dug into the electronics yet, I don't have the equipment, but if the Two Star works, I'm good with that. I will do a more thorough stress test soon.

[OzAndrewJ]

Gday ryanr

OK, it sounds like the level sensor isnt working.

Just do a 90deg slew test ( using the setting circle )

and noting the handsets Alt before and after

If that passes OK, then its sounding like the level sensor is playing up.

Sooo, if you dont do the auto align, it should work happily,

as thats the only time the level sensor is used.

Andrew Johansen Melbourne Australia

[ryanr256]

Gday ryanr

OK, it sounds like the level sensor isnt working.

Just do a 90deg slew test ( using the setting circle )

and noting the handsets Alt before and after

If that passes OK, then its sounding like the level sensor is playing up.

Sooo, if you dont do the auto align, it should work happily,

as thats the only time the level sensor is used.

Andrew Johansen Melbourne Australia

 

But it works fine with other 497 handsets. That is what stumps me.

 

I've now got 3 other 497s that work and this one that doesn't.