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Last updated: 31 December 2012

This page is for comments and user feedback about ETX telescopes. ETX models discussed on this page include the ETX-60/70/80/90/105/125 (EC, AT, BB, Premier Edition). This page also includes comments and feedback of a general nature. Comments on accessories and feedback items appropriate to the ETX-90RA, DSX, and DS models are posted on other pages. If you have any comments, suggestions, questions or answers to questions posed here, e-mail them to me for posting. Please use an appropriate Subject Line on your message per the Site Email Etiquette. Thanks. Remember, tips described on this site may invalidate the warranty on your telescope or accessories. Neither the submitter nor myself are responsible for any damage caused by using any contributed tips.

Subject:	ETX125-PE lock problem
Sent:	Thursday, December 27, 2012 08:43:47
From:	Hatto, Stuart (
Hi Mike  great site  has helped me enormously in choosing my new telescope.
I have managed to purchase a NEW ETX125-PE, however first time out the
DEC lock just rotated without locking. I now have a replacement but I am
worried this is a shortcoming of the ETX and am wondering whether to
send the replacement back and get a refund.

I didn't overtighten the lock  was very careful about that, but I just
don't see how this lock could hold the weight of a DSLR at prime focus.
Do you have any advice?
Mike here: If the DEC lock never tightened on first use, it was likely broken by the previous owner (or store) OR it could have been overly tightened prior to shipment and movement of the OTA broke the mechanism. The RTA can be easily broken by overtightening to hold a lot of weight but it should not break under normal use. I recommend doing prime focus imaging through the eyepiece hole using an adapter like the OPT Camera Adapter (see my review on the Accessory Reviews: Astrophotography page). If you are concerned about the weight, add a counterweight system; see the Helpful Information: Astrophotography page for several articles on counterweights.


Thanks Mike!

There is so much info on your site I'm sure I'll get to it eventually :)

I was thinking of starting off with afocal photography before bolting in
my DSLR - the new compact digital cameras are so light I think it will
eliminate early worries about the strength of the locks.

Anyway, thanks again for the reply - I'll be sure to send you my first image.

Mike here: Afocal astrophotography works fine for many objects. Best to use an adapter to hold the camera (see the Accessory Reviews: Astrophotography page). Also, many tips on the Helpful Information: Astrophotography page for many types of astrophotography and cameras.

Subject:	re:  Testing ETX Motor Function Without Autostar
Sent:	Thursday, December 20, 2012 22:56:15
From:	richard seymour (
You lucked out... v1.2 *does* (or "did") have Safe Load,
so the loading of 43Eg was (partially) successful.

But yes, you were too impatient... with ASU in Safe Load, it takes about
30 minutes for the load.

But: now that you have most of 43Eg in there, the next load (if done
"normally"... do NOT invoke Safe Load, just let ASU kick the Autostar
into Download mode)
should only take about 20 minutes.

There is no "in progress" indicator on the Autostar...
but there is one in the bottom left margin of the ASU screen on your PC.
The Autostar will self-reboot when the download is complete
(you could load twice as fast by using StarPAtch from
... the free version does half the load in one minute, then slows down
to "Meade speed" for the next 10 minutes)

Try again, but with fresh batteries (and more patience)


From:	steven flick (
Roger that - thanks all.  What really threw me was that the display
continued to say "ready" (I think that was it, or close to) after I had
"started" the upgrade - I really expected it to at least provide some
confirmation that the process had begun.

Many thanks --SF

Subject:	Re: Testing ETX Motor Function Without Autostar
Sent:	Wednesday, December 19, 2012 15:36:59
From:	steven flick (
A follow-up on Subject thread and perhaps another question or two if you
could possibly be so kind:

After my rather idiotic external power mishap with my new 125PE, I just
happened to catch a ridiculous auction deal on a replacement HBX
(purportedly new-without-box, but I really doubt it).  I powered it up
along with the scope (v. 1.2 - wow?) and it promptly displayed the "use
with ETX" message.  Being unable to further access the menu, I prepared
it for an ASU safe-load upgrade to v4.3Eg (from previously-saved
download).  Shortest version is that nothing beyond the
already-displayed "Flash Upgrade Ready"(or the like) appeared on display
after I hit "Upgrade Now" button.  Although I hadn't done this before, I
didn't think this was correct, but as the Keyspan adapter was indicating
some sort of data flow, I waited something between 5-10 minutes for
another display message, but no change.  As the scope was on internal
battery power and as I really expected to see some sort of "Upgrading"
or other progress message, (but couldn't locate any specific upgrade
message sequence on your site), I finally decided something must be
wrong and proceeded to shut down the scope, planning to evaluate and
perhaps try another safe-load.  Upon re-powering the scope, I was
startled to find that the Welcome scroll appeared along with a v.43E
notation.  (To repeat, I had received no "completed" upgrade message,
nor any progress indicators.)

Puzzled but pleased to see anything but a blank screen or perhaps
gibberish, I set up time/date/locale, and was happy to see the 125
responding and performing a level/tilt (I had feared that scope boards/
motors also were toast).  However, in two test automatic-align attempts
from the home position, the scope seemed to stall at the "selecting
star" message, despite letting it decide for several minutes on both
attempts before powering off.  I performed a reset, re-entered info and,
coincidentally or not, it quickly slewed to first star and the mock
center was accepted, but it then again "stuck" on selecting the second

So now I'm wondering -

- Could this extended star selection time possibly be normal? (surely
not?) Is this a known issue? (again, sorry if old news, I did search the

- And, can an upgrade somehow be "partially corrupted" so as to still
appear to function, but fail on particular actions?  (My PC is pretty
fast, so it just may be possible that what I had understood to be an
upgrade time of around 20-30 minutes could have been completed, or
nearly completed, in around 10. Have you ever heard of the strange but
seemingly successful upgrade procedure I reported above? (I promise, the
facts above are correct.)

- Also, Align mode not continuing to pick up time from LNT after initial
manual time entry in both align and setup modes (LNT dot working fine).
I'll check the battery shortly, but I would note that the original owner
did damage and (very nicely) repair the finder mount, and he indicated
that LNT was still working fine - I guess I may have to
dissemble/troubleshoot LNT via the PE tips on your site if battery
checks okay.

Thanks much, 
Mike here: Two points about the upgrade from really old versions: 1) you might need to install a slightly newer version than 1.2 (I forget when the FLASH LOAD code was added), and 2) it will take about 30 minutes before ASU will complete the installation. If the download did start, interrupting it before completion will corrupt the installation. If you need to try an older version, see the "AutoStar Software Archive" on the Helpful Information: AutoStar Info page. BUT since you did get something after cycling the power, it could be that the installation was OK (or not). I would suggest reinstalling and waiting at least 30 minutes.


Thanks Mike - 
One very quick point to clarify - if/when I try a reinstall, SHOULD I
see occasional upgrade progress messages and a "completed message" (or
beep) on the display (given a "normal" update process)? 

Mike here: Hi from my observatory.
Normally the AutoStar will do a reset at the end, and so beep. Other progress messages are iffy. Best to watch the clock. Or use StarPatch, which does the installation in WAY less time than Meade's program.


Great thanks -
PS - LNT battery dead as doornail- 0 volts - lowest reading I've ever
seen. That should fix the time setting.  Good seeing.
Mike here: Good you found that culprit.
Thanks. Temp getting cold. Now 37F and going down.

Subject:	Quality of new ETX 90
Sent:	Tuesday, December 18, 2012 19:50:05
From:	Steve Brown (
I am intrested in buying the latest model of the ETX 90 telescope
($400.) Is the quality of the new scope as good as the previous model at
the new low price? what are the changes? Thank you.
Mike here: I don't have one so can't speak about it. Perhaps those who have the model will chime in.

Subject:	Hi From Max
Sent:	Tuesday, December 18, 2012 12:47:34
From: (
Just wanted to say that I've returned to the Mighty ETX. After operating
telescopes bigger than 3.7meters and owning my own 16-inch dob, 130mm
triplet and 10-inch SCT along with an AT-66 (that describes my current
stable of scopes), I have returned to the Mighty ETX.

Yes, I'm about to take it out at work and show my colleagues the Sun,
Sol, our home star. Except now my ETX is deforked, as I won't own forks,
I used GEMs. Looking forward to hearing from you. Also, I'm a POD head
and have published extensively in ATT and other rags.
Max Corneau
Mike here: Glad to hear the ETX gets some use! I love ATT. Only been a subscriber for a couple of years. And of course, love my SkyShed POD.

Subject:	ETX 80 and DSLR
Sent:	Monday, December 17, 2012 20:11:54
From:	Stephen Olson (
Long time. Hope all is well. Have not used my ETX80 in ages. Decided to
add my Canon DSLR to it for fun. I have a link to my facebook page. I
tried to look for you, but no luck. Here is a link. Hope you can get to
also here is a link to my page so you can friend me!! Also any telescope
people that would like to be friends would be great!
Stephen Olson.
Mike here: Hi from my observatory. I'm imaging Ceres right now with my DSLR.
I'm not on Facebook. Too many security issues there.

Subject:	Re: Testing ETX Motor Function Without Autostar
Sent:	Thursday, December 13, 2012 16:28:00
From: (
Did we established the regulator was OK?

If not a simple test is to connect a DVM ( Digital Volt Meter) from the
center lead to the left lead and you should get system voltage, (about
12 volts).
Next connect the DVM from the center lead to the right lead and you
should see about 5 volts.
If it passes this test, as Dick said "look elsewhere".

Subject:	ETX-90 power supply question
Sent:	Tuesday, December 11, 2012 17:35:02
From:	Snuffy Smith (
I owned an ETX-90 for about three years until Hurricane Katrina washed
it away.  I am now about to purchase another one and I have a question.

I had an AC power supply for my now-gone ETX-90 -- plugged it into 115
AC and it put out the correct voltage for the ETX-90 with a plug that
matched the external power jack on the ETX-90.

What voltage is required for the ETX-90?

Regarding the plug that plugs into the ETX-90 external power jack:  How
is it polarized?  Is the shell NEGATIVE and the interior connector
POSITIVE or is it reversed with the shell being POSITIVE?

Mike here: Power requirements for the new ETX-90 are the same as for your old one. Central pin is positive.

Subject:	re: Testing ETX Motor Function Without Autostar
Sent:	Saturday, December 8, 2012 17:22:39
From:	richard seymour (
> I would ask you if you know if simply "jumping" the 7805 into the circuit
> **with the existing (blown?) regulator still in-line** would be safe for
> the components.

I wouldn't blindly do that...

If the regulator died in an "open" state, it might work (note: "might", see below).
If the regulator died in a "shorted" state, (and there are three "short" paths possible),
such a test could quite possibly damage things worse.

Even in the "open" state, we don't know what the 5v snubbing circuit of
the old regulator would do when it saw the (perhaps a tiny bit higher)
5v of the new regulator... would it try to shunt it to ground?

At the very least, I'd try to ohmmeter the old regulator to assure
myself that it's not a "dead short" between any two of the pins.
Switching to the meter's Voltage scale, I'd apply a momentary bit of 12v
while watching the 5v output (looking for anything from zero to 12v to
come out the "5v" end).
If it put out 5v, then i'd investigate elsewhere for the failure.

Only if all of the above assured me that there were no shorts, and 12v
in produced zero out, would i think of straddling the old with the new. 
And i'd still fret about it.

good luck


From:	steven flick (
Richard (and Mike) -

Agreed - thanks for reply.  Good to hear from the foremost authority.

I've since gotten the proper stuff together for a "standalone" autostar
test (thanks to Mike's site) and concluded that the regulator was
working solidly (9v in - 5v out) - it's something else that isn't. 
Close to throwing the towel in, but still pondering what I can test on
the board - no doubt power is getting to (and leaving) the regulator, so
wondering how the thing could be totally dark - anything you might
suggest (IF you have time) is appreciated.  My meter's resistance mode
is currently blown, (don't ask - replacement on way), but the top
capacitor showed 9v (as I recall), while the bottom one read something
negative (with power applied and polarity correct).  Little confused
about that, but don't really fathom the world of C's anyway - figured
something must be better than nothing.  Could crystal possibly be messed
up?  More likely IC shot or something.  Tried soft reset - zilch.  I
don't *see* any continuity issues anywhere - perhaps you know of some
other usual suspects (beyond VR) to inspect.  (FYI - it is "newer style"



From: (
Sorry, I've been away awhile. I your Autostar totally dead? If so
respond and open it up.

And more:

The 5 volt regulator on your autostar (Audiostar?) is labeled as 

It is a 3 pin component. Download the datasheet and check the voltages.

I have an older autostar and obviously there were revisions to the
circuit board which placed the regulator in a different position.

Let me know.

Mike Amonett


Thanks Mike - did manage to test this already - the reg. is a-ok - still
working on it.


Subject:	ETX-90 slipped baffle
Sent:	Friday, December 7, 2012 08:45:43
From:	Ralph D'Andrea (
I have recently acquired an ETX-90 with a slipped baffle.  I did this
knowing that Meade no longer fixes them and I would have to do the job

I have thoroughly searched your site and other sites and have found
plenty of information about how to re-attach the baffle (epoxy, RTV, 3M
Command, etc) but there is precious little good information on how to
remove the baffle safely.  It is REALLY stuck on there.  Once that is
done, there is the problem of removing the adhesive from the corrector. 
I have seen "roll it off with your fingers" and "use the adhesive still
on the baffle to pluck it off."  Do you have any additional guidance or

Regarding re-attachment, I am currently leaning towards cutting my own
ring out of a 3M Command strip as it seems to be the safest adhesive to
avoid tarnishing the secondary spot.  My first choice was aquarium
cement but I am a little worried about the acetic acid it liberates
during the cure.   Any opinions?

I wish Meade still supported these old scopes.  I would have willingly
spent $75 and shipping both ways.
Mike here: The articles on the Helpful Information: Telescope Tech Tips page is all the information available. And yes, avoid any acid or materials that could outgas and coat the optical surfaces.

Subject:	New model of ETX 90 3514-04-15
Sent:	Wednesday, December 5, 2012 02:05:19
From:	Mike Corley (
Have you received email from any one else who has an ETX90 model
3514-04-15?  My grandson took the bottom section of my brand new
telescope, but did not document or photo what he was taking apart.  Now
I have a small box full of parts and no idea how they go together.  I
have talked with Meade, they were of no help what so ever.  They claimed
they could not even tell me the name of the company in China that build
the telescope, much less provide any documentation.

Mike, I am in real trouble at this point.  I can't really blame my
grandson for possessing such a strong curiosity.  For a twelve year old,
he uses tools rather well.  He just needs to learn to document what he
takes apart so that he can put it back together.  I am hoping some other
owner of this telescope would be willing to help me figure out how to
put this scope back together.  After all it has not yet even experienced
"first light".  I must repair it!   There is a small pop out round area
on the bottom.  I need someone to pop this out and make a detailed
photo/drawing of how things go together.  Then if possible, the bottom
cover needs to be removed so that the internal workings can also be

PLEASE Mike, help me find someone that can help.  Otherwise I am going
to have to purchase another scope, just to take apart careful and
document it's construction!
Steven Corley
Waller, Texas
Mike here: Any emails I receive in response to queries are always posted on the ETX Site. None have been received regarding your problem. You might contact Dr. Clay Sherrod for his Supercharge service; he could probably get it all back together as part of his service. Details on the "Supercharge Service" page linked from the ETX Site home page.

Subject:	Testing ETX Motor Function Without Autostar
Sent:	Tuesday, December 4, 2012 13:38:41
From: (
This is in response to the question posted on your site 12-04-12.
"Testing ETX Motor Function Without Autostar"
If he can open the autostar there is a minature 5 volt regulator (looks
like a 7805 TO220 but smaller).
It's solderd in there kinda sideways.
Reverse polarity will blow this for sure. He needs to look for a bubble
in the center of it, if so repace it with a standard 7805 regulator in a
TO220 package; it's a little larger but it will fit!
I fixed my autostar like this.
Mike Amonett


From:	steven flick (
Good stuff - thanks much to both of you.

Since no good deed goes unpunished, would like to get a little more down
in the weeds on it with Mike A. - if you have the time, Mike.

(Background: I've conducted the standalone Autostar power-up test that
Mike W. referenced in his reply [at least I *think* I did it correctly]
- no response at all from Autostar.  I've also, I believe, been able to
confirm that I am getting a 12v output from the mount out to the HBX

I've attached a couple of shots of the Autostar board FYI.  I happened
to have been looking at the VR you described anyway (I think), and,
kinda like all the other components I examined, there's no real evidence
of any "blowout" (or "bubble") there. (There is no center pin connection
to the VR, but the area looks clean, and I believe that's a ground pin
that might not be required in this application.)  I'm far from expert,
but I think that the lack of clear visible evidence of failure does not
necessarily mean the the regulator (or anything else) isn't "shot".  So,
based on your reply, I think that it might be worth spending $2 at Radio
Shack to test the theory.  As I'm dumb on these things, I would ask you
if you know if simply "jumping" the 7805 into the circuit **with the
existing (blown?) regulator still in-line** would be safe for the
components.  At first blush, my thinking was "it couldn't hurt," but, as
stated, I ain't no expert, so seeking opinion.  (I don't want to have to
chop out an original, still functional component for the sake of a test
if it isn't truly necessary.)  Also, I'm thinking maybe the 220
packaging might indicate more of a heat problem for the 7805 than the
original surface-mount VR - any issue?

Again thanks for assistance, Mike(s).

Steve F.

Subject:	Testing ETX Motor Function Without Autostar (?)
Sent:	Sunday, December 2, 2012 19:28:30
From:	steven flick (
Hello. First, I searched for this information on your extensive site for
quite some time but couldn't find - I truly hope I'm not being

I've managed to break my 125PE by misapplication of an external power
supply - let's call it "reversed polarity," although I don't think that
was exactly it.  Result: mount power light turns on - nothing at all
from 497 Autostar except (believe it or not) a very faint intermittent
"clicking" sound from speaker(?). (To be clear - sound is from the
Autostar, not the base). 

So - now time to troubleshoot.  The mount power light *seems* to point
to a fried HBX rather than the mount circuitry, but of course I'm not
sure if it's HBX, mount hardware, or both.  Opened up the HBX and found
nothing obviously amiss (though I'm not smart enough to test very much
in place, and really don't wish to chop out capacitors, jump things,
etc., in there prior to pinpointing the issue). So, my initial question
is - is there any practical way to confirm basic mount functionality
EXTERNALLY without Autostar? (Maybe adding a jack to the unused HBX cord
end and jumping leads?)  Other than that, would be looking at a base
dismantle/test, with which I have zero experience (though I will look
into any procedures that might be on this site).

FYI, I know of no one having a Meade to test my HBX on, and I am far
from any Meade dealer. Batteries are strong.  External power supply
still works fine with my Celestron.  I did perceive (imagine?) a slight
burning odor at the time of the problem.

Thanks much in advance for any suggestions-

-S. Flick  
Mike here: I suspect you did fry some component. Probably on the AutoStar but could be on the circuit board in the ETX. A possible test is to disconnect the AutoStar and then power on the ETX. If the ETX motors slew the telescope then the ETX side is possibly OK (unless the blown component/trace is something in the AutoStar connection circuitry). You can test the AutoStar by making an external power source for it and see if it comes on when not connected to the ETX. See the Helpful Information: AutoStar Info page.


Thanks for answer - powering up scope produces only power light - no
slewing at all. I'll check Info page for autostar external power -


Subject:	My corrector lens cell is loose....
Sent:	Saturday, December 1, 2012 21:39:40
From:	Daniel M. (
just tonight I had my dew shield on my ETX-125, but when I took it off,
the entire black piece and corrector lens cell began to loosen....and
the dew shield wasn't coming off. I did eventually get it off, but now
that the entire cell seems to be loose whenever I twist it, it scares me
as I hope I didn't knock the optics out of alignment. I didn't loosen it
until it actually came off, but it was able to be loosened if the cap
was on too tight. I tighten the cell as tight as I can to make sure it
never comes loose. So what is the best answer to this? Be careful when
taking on/off the lens cover? Will the alignment of the optics be off?
Thanks, Dan
Mike here: The corrector lens housing can be unscrewed (as you discovered). This can happen when unscrewing a dew shield, a screw-on solar filter, or even the aperture cover. Holding the lens housing while removing these usually prevents the housing from unscrewing. If it does come loose, usually retightening the housing is all that is needed. However, doing a collimation check "star test" is a good idea. For more on star tests and collimation, see the Helpful Information: Telescope Tech Tips page.

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