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[RobbW]

Does anyone have experience with troubleshooting a Meade #494 AutoStar system? I think I may have killed mine. The last time I had my Meade DS-2130AT out was last Wednesday, April 21. At the end of my observing session, I used the controller to put my scope into park mode and turned it off. I brought my scope back inside and haven't tried turning it on again until last night.

My scope is powered by 8 AA batteries that are loaded into a pack and connect to the motor drive using a connector that you would find for a 9V battery. I don't like burning through batteries all the time. So I have been searching online for instructions on making a DIY power supply. I came across discussions on using a 12V jump-start battery as a portable power supply.

I bought a cigarette lighter adapter/cord and 9V battery connectors from Radio Shack last night. I rigged up the 9V connector to the end of the cord and proceeded to test out the PSU on my scope. I connected the cord to the scopes power connector and then plugged the power cord into the cigarette lighter outlet on the jump-start battery. I flipped the power switch on the scope to the "On" position and nothing happened. The red LED power light did not come on, the handbox controller did not light up, and the motor drive did not power up. I realized I must have the polarity of the 9V connector reversed on the fabricated power cord. I immediately turned off the power switch on the scope.

I disassembled the power cord and switched the wire connections on the 9V connector. However, this time I didn't fully reassemble the power cord electrical tape and the works. I only crimped the negative/black lead and left the positive/red lead unattached. I wanted to be able to very quickly test the power connection, but be able to immediately cut off power if need be. With only the negative lead crimped on, I reattached my power cord to the scopes power connector. I turned the scopes power switch to the "on" position. And very quickly, I touched the positive leads together and then separated them. The red LED power light had flashed on during this test. So I figured I had the polarities correct this time.

Anyway, I removed my power cord from the scope's power connector and proceeded to permanently assemble the power cord. After everything was taped up and ready to go, I reattached my power cord to the scope's power connector and turned on the scope. The power light came on and was steady, and the handbox controller turned on and the LCD screen displayed the AutoStar version info. Three seconds later, the handbox controller went black and the scope did not initialize.

I turned the power off and then back on again. The same thing happened. The controller lit up for three seconds and then went black again. I figured there must be something wrong with trying to use the jump-start battery as a power source. So I disconnected it and reinstalled the 8 x AA battery pack. I decided I would just use batteries until I came up with a usable solution to a portable PSU. With the battery pack reinstalled, I turned the scope's power on. The same thing happened as with the PSU. The handbox turned on and then went black three seconds later. This happened over and over with no resolution.

I have resigned myself to the fact that I must have fried my AutoStar controller when I had the polarity reversed the first time I tested the PSU. Drats!!! Anyway, I spent the remainder of the night searching for a replacement controller online. I have found a person on Craig’s List selling a brand new, in the box, never used #497 AutoStar controller. This is a better controller than the 494 I just destroyed.

I am currently making plans for a pickup of the new controller sometime within the next few days. However, in the meantime, I thought I would post my experience and see if anyone had any thoughts on whether my 494 controller truly is toast.

[RobbW]

Well, I'm set to pick up a 497 controller tonight. Can anyone confirm that the 497 controller is directly compatible with the motorized mount that came with the 494 system? Or will I need an adapter or a different cable?


Update
I just heard back from Meade support, and they confirmed the 497 will connect to my mount without any modifications necessary. So, looks like I'm good to go.

[Chicago Astronomer - Astro Joe]

Robb,

I just read about your electronic woes.

I really hate when this happens...and it has happened often over the years with various devices. I just undertook a Green laser operation...that resolved successfully...

How fortunate that you found a replacement controller...but let's hope that the damage just resides there...and not in the motor controls of the mount. The volts and amps need to be matched up to the amount the batteries provided and reversed polarities are never good.

Let us know the new developments with the new controller.

We are at the mercy of the electron.

[RobbW]

Thanks for the words of encouragement, Joe. But alas, it looks like it is not to be. I picked up the new #497 controller last night. When I got home, I took it out of the box, hooked everything up, and turned on the power. The 497 controller powered on, beeped after a couple seconds, displayed "Initializing...", asked me to press 1 for text in English, and then displayed the long warning about pointing the scope at the sun. When done, it asked me to press 5 to indicate I have read and understand the warning. That's when things took a turn for the worse. As soon as I pressed 5, I got a "Motor Unit Fault" error, and it told me that switching the handbox between scopes, low batteries, or an obstruction could be the cause of the problem. No matter how many times I turned the AutoStar off and then back on, I kept getting the same "Motor Unit Fault" error. Would you have any further suggestions? I know the AutoStar #497 is supposed to be compatible with all DS models, but could this one be different? The packaging the controller came in, and the controller itself, both say Meade #497 ETX Controller. Is it possible this is a #497 controller that is only for ETX models?

When I turn on the power, the controller lists the AutoStar software version as 2.0. Would updating the firmware make any difference?

[Chicago Astronomer - Astro Joe]

Robb,

"Motor Unit Fault"

Not good.

It sounds like damage to the mount.

Blows.

Get up to the mount, and see if you smell any thing burnt. A slight acrid odor is telltale of burnt out components. Accidents happen, but it's no consolation.

Been there.

Rechargeable batteries would have been ideal. I use "Eneloops". The best rechargeable batteries I have ever used, and last forever.

I don't have any advice on this matter on the failed go-to, but is the scope still able to slew manually? At least observations won't cease.

Tell me more.

[RobbW]

I took apart the whole mount tonight to look for any signs of damage. I couldn't find anything. I even tested the motors by applying power to their terminals directly from the battery pack. Both motors spun just fine. So the motors are okay. I do not see any burnt or melted areas on the circuit board. I checked to make sure there was nothing blocking the gear sensors near each motor.

I also used directions I found online to build a new HBX cord to connect the handbox to the mount. I wanted to test to make sure the original cord was not damaged somehow. Both cords performed exactly the same. Still get the MUF error.

I bought and installed new, fresh batteries. Still MUF. I took apart the controller to see if anything was loose or floating around in there. Everything looked fine.

I can't figure it out. The only idea I have left is that maybe the HBX firmware just needs to be updated. Unfortunately, the #505 cable I ordered to connect my HBX to my PC for the update is back-ordered. So it will be almost two weeks before I can test that hypothesis.

Yes, I can still slew my scope manually, meaning with my hands and not with the powered mount. So I can still observe. I just won't be able to track anything. The only concern I have about manually slewing is the potential for messing up the gears in the mount somehow by man-handling the scope.

Oh well, I think I'm going to grab my binocs and head outside for a bit before heading to bed.

[Chicago Astronomer - Astro Joe]

Robb,

Electrical problems are most frustrating.

The cord might indeed be bad, considering the motors are working, but I'm thinking perhaps some little rectifier or diode might be at fault in the mount's circuit board.

I hope it's just the cable...

[RobbW]

Unfortunately, I don't think it is the cable. I made a new cable from a Cat5 patch cord I had laying around. It performed just the same as the original cable. Still got the MUF error.

[Chicago Astronomer - Astro Joe]

Robb,

Damn.

I'm hoping your skills can bring this back from the brink.

[RobbW]

Thanks for the optimism, Joe! Tonight, I stripped the mount and motors down to basic components to make sure they were clean and moving freely. Everything appears to be in good working order, except that it doesn't... work! My last hope is that the 497 controller needs a firmware update, and hopefully, that will be all it takes. Unfortunately, it will be nearly two weeks before I receive the cables I ordered to be able to download and install firmware updates.

At this point, I think I'm resigning myself to having to man-handle my scope and manually point it to the targets I want to observe. It would have been nice to have an operating Go-To scope that could help me learn the night skies, but it seems vaguely comforting to realize that I'm going to have to figure it out on my own. The biggest disappointment is considering the time, money and effort I have put in to getting this scope up and running (or not running). By now, I probably could have purchased a brand new, in-the-box scope that would be just as mediocre as the used one I'm trying to fix up!

[Chicago Astronomer - Astro Joe]

Robb,

I have always used all-manual scopes.

Not that I'm against them, but it's just what came my way.

But, going manual forces one to learn the skies better and master the "Star Hop" technique to locate your targets.

I have enjoyed my astro buds who have go-to scopes, as it does make finding things faster and one can punch in many targets in a session. I dig fellow Chicago Astronomer Bill, who is masterful in locating objects quick and accurately just by using a star chart and star hopping.

What we have been doing recently is using the often over-looked setting circles...with good success. With a good star chart and R.A./Dec coordinates, targets are found pretty easy. And...with the C11 SCT...I have the "Astro Master" Digital Setting Circle accessory. I have yet to master it, but while playing around with the box, it does show me numbers, arrows and a host of other data that will make this season of observation a good one.

Sorry about your electrical mishap Robb, but perhaps it will nudge you in going all manual and learning the star hop better.

[RobbW]

Actually, I'm not all that against going manual and having to really learn the skies. I would prefer to learn them better. There are two main reasons I went with a GoTo scope: 1) I really want to get my daughter hooked on astronomy. But as anyone who has spent more than 5 minutes with a four-year-old will tell you, it's useless trying to hold their attention for more than 3 minutes! I wanted to be able to find targets quickly and easily for her sake; and 2) I care far more about the auto-tracking feature the GoTo mount offers more than the actual GoTo function. I hate having targets floating out of view and having to constantly jerk the scope over a bit to stay on target. I really dig the mount doing the working of keeping the target centered in the FOV.

However, now I'm kind of wishing I had gone with a scope/mount combo that would have been more friendly to manual use. It turns out that point #1 above really isn't an issue. What I had not thought about is the fact that by the time it is dark enough out to start observing, my daughter is (or at least should) be in bed already. Especially now that the skies don't go dark until later at night. I guess I was just relying too much on the "child astronomy education" justification to get my purchases past the wife that I didn't think about the practical applications of the scope.

Oh well, lessons learned.