10 replies to this topic

[Tavi]

Hi all,

 

A friend who own a Celestron Evolution 8 alt-az mount asked for help. He used a solar Lunt telescope and the mount works well for many hours in the Sun at an astronomy festival.. Altitude motor has stopped working. At home, he opened the mount and change motors connectors on the mainboard. The other motor stopped working, so the driver failed just on one channel. 

 

I've ordered the L293DD chip from a trusty supplier and replaced the bad one because I own a reworking SMD station.

 

After replacing the driver both motors worked for a while. I glued a small radiator on the L293 because it was hot when in use.

 

I didn't know how to use this kind of mounts, I tried it to bypass the alignment but failed. Just trying to move the alt and suddenly, the mount stopped entirely, including the hand controller. I've restarted it several times with no luck. With the main switch open the hand controller display an error message that it cannot connect, there is a tick sound and the LED blinks, also the HC display led blinks. With main switch closed nothing appeared on the display, just flickering. I tried different things to see what is wrong but nothing find.

 

I think the board is dead. It is replaceable? Can I order it from Celestron as a spare? I don't know how to troubleshoot it further, so please help me with suggestions what to do next.

 

Clear sky,

Tavi

[dave85374]

My Evolution board failed about two years ago and I took it to my dealer and he ordered the replacement board and installed it.  Celestron told the dealer it would also need a new battery.  Both items were replaced on warranty.

[mlord]

The tick sound is coming from one of the onboard switching power supplies (on the Evolution main circuit board).  It usually indicates a dead short circuit somewhere -- almost always the L293DD chip again!

 

Adding a heat-sink to the top of the chip doesn't help like one might expect -- I think the datasheet even says something about that, with it acting more as an insulator than a radiator.  Celestron themselves even tried it on one revision, and abandoned the heat-sink again after that.  There are specific requirements outlined in the datasheet for heat-sinking.

 

So.. swap the chip again.

 

Cheers

Edited by mlord, 22 June 2024 - 04:26 PM.

[mlord]

There is more information about the Evolution, and troubleshooting as well, back in the original thread here:  https://www.cloudyni...-a-look-inside/

[elwaine]

I recently purchased a package including the Evo mount, a C8 Edge (which I love), StarSense Camera (which I like), and a so-so tripod. 

 

The WiFi failures are driving me crazy, and Celestron support is not much help. I am using the latest firmware. Even in places where my Evolution mount is the only one for miles, and there are no other sources of electrical interference, the WiFi connection either spontaneously quits completely, or maintains it's WiFi output but disconnects from Sky Portal or Sky Safari Pro and presents an error message saying that the WiFi signal is good but the mount cannot respond to the software. I have to shut down and start the alignment process all over again. And then it is likely to fail again later on that night.

 

Public outreach is the main reason I bought the C8/Evo, and it's a real pain when I lose connection with the mount mid-session. So I decided to switch from Wi-Fi to the Hand Controller, only to discover that Celestron omitted a real time clock in the mount or in the HC, so time has to be inputted at the beginning of each session. Not that big a deal. But the HC only stores one location and I travel around a lot to do outreach at different locations. So I have to input that data as well.

 

Celestron's solution: buy a SkySync and plug it in to one of the Aux. ports on the mount. Yes sir. Why spend 50 cents on a RTC and enough memory in the HC to store several different locations when they can sell you a $10 RTC/GPS unit for $189? Thank you Celestron. 

 

Celestron is planning on releasing the Origin soon. It looks like it rides on an Evolution mount. I can only imagine what fun people will have with Wi-Fi failures during imaging runs. 

 

Larry

[Noah4x4]

I recently purchased a package including the Evo mount, a C8 Edge (which I love), StarSense Camera (which I like), and a so-so tripod. 

 

The WiFi failures are driving me crazy, and Celestron support is not much help. I am using the latest firmware. Even in places where my Evolution mount is the only one for miles, and there are no other sources of electrical interference, the WiFi connection either spontaneously quits completely, or maintains it's WiFi output but disconnects from Sky Portal or Sky Safari Pro and presents an error message saying that the WiFi signal is good but the mount cannot respond to the software. I have to shut down and start the alignment process all over again. And then it is likely to fail again later on that night.

 

Public outreach is the main reason I bought the C8/Evo, and it's a real pain when I lose connection with the mount mid-session. So I decided to switch from Wi-Fi to the Hand Controller, only to discover that Celestron omitted a real time clock in the mount or in the HC, so time has to be inputted at the beginning of each session. Not that big a deal. But the HC only stores one location and I travel around a lot to do outreach at different locations. So I have to input that data as well.

 

Celestron's solution: buy a SkySync and plug it in to one of the Aux. ports on the mount. Yes sir. Why spend 50 cents on a RTC and enough memory in the HC to store several different locations when they can sell you a $10 RTC/GPS unit for $189? Thank you Celestron. 

 

Celestron is planning on releasing the Origin soon. It looks like it rides on an Evolution mount. I can only imagine what fun people will have with Wi-Fi failures during imaging runs. 

 

Larry

Celestron WiFi has always been notoriously flaky through three generations of progressive (but limited) improvement. The issue is it uses the 2.4Ghz channel. Many of us gave up on Celestron WiFi years ago and switched to alternative solutions such as that described in my CN Signature. Even so, I had to purchase 5Ghz MESH extenders. 

 

My SkySyn GPS has been redundant ever since I switched to CPWI and control from a laptop, which takes Location, time, DST etc from Internet location services. Half the fun of Cloudy Nights is finding solutions to the many challenges put before us.

 

Don’t underestimate the sophistication and precision of a computerized tracking telescope. One fluttter of WIFi resulting in a “lost data packet” and the missed heartbeat means your alignment is dead. By contrast, if when watching a live streamed movie a few frames are dropped your eyes won’t notice. Frankly, WiFi is limited technology. My route using two computers and Remote Desktop means that if the WiFi drops out the mini-computer at the scope keeps going, so reconnection of the second computer (merely acting as a dumb terminal) doesn’t result in any lost data packets. Celestron WiFi is what it is and the hand controller is much more reliable. But if one wants reliable wireless remote control, there are many alternatives, mainly described in the EAA Forum.

[elwaine]

 Many of us gave up on Celestron WiFi years ago and switched to alternative solutions such as that described in my CN Signature. Even so, I had to purchase 5Ghz MESH extenders. 

 

My SkySyn GPS has been redundant ever since I switched to CPWI and control from a laptop, which takes Location, time, DST etc from Internet location services. Half the fun of Cloudy Nights is finding solutions to the many challenges put before us.

 

Phil, thank you for your thoughtful and informative remarks. Unfortunately, I have neither the knowhow nor the will to undertake the route you chose in solving a problem that Evolution mount owners should never have had in the first place. I was aware of CPWI before I purchased an open box SkySync (at a very good price), but I do not have a Windows based computer, and a SkySync, even at its original retail price, is a heck of a lot cheaper than even a modest portable Windows computer. Too bad (for me and others) that CPWI doesn't have a version that would operate on an IOS platform.

 

Overall, thanks to the superb optics in my copy of the C8 Edge, I'm still happy I bought the kit, even though I am angry at the bean counters at Synta for having chosen to nickel and dime their customers. Oh well. One can't have everything in life, can one? 

 

Larry

[rcooley]

I dunno, everyone has a different experience with their “stuff”. That’s why they have yelp, I suppose. I’ve had my Evo 8 since 2016, never really had an issue with the original WIFI until this summer when suddenly it wouldn’t access sky safari/sky portal. Put in a help desk ticket to Celestron, and two days later got an email from the tech person.  She sent me a step-by-step recipe to the wake the WIFI back up. Works perfectly again with both SS & SP.  Also… I’m with Dave85734 as far as using the Asiair to plate solve. That system in conjunction with my Evo is bomb proof as far as I’m concerned. And targets are always dead center, whereas when I used to do conventional two-star alignment it could be a bit off. With plate solve, my Evo slews robustly to whichever target I ask it to, whenever I ask it. It’ll slew up down, left right, meridian, horizon, and it’s always spot on. I was actually marvelling to myself the other night while EAA’ing various galaxies above me, just how solid this thing is. Just another person’s “experience” tho. Cheers…

[elwaine]

I dunno, everyone has a different experience with their “stuff”. That’s why they have yelp, I suppose. I’ve had my Evo 8 since 2016, never really had an issue with the original WIFI until this summer when suddenly it wouldn’t access sky safari/sky portal. Put in a help desk ticket to Celestron, and two days later got an email from the tech person.  She sent me a step-by-step recipe to the wake the WIFI back up. Works perfectly again with both SS & SP.  Also… I’m with Dave85734 as far as using the Asiair to plate solve. That system in conjunction with my Evo is bomb proof as far as I’m concerned. And targets are always dead center, whereas when I used to do conventional two-star alignment it could be a bit off. With plate solve, my Evo slews robustly to whichever target I ask it to, whenever I ask it. It’ll slew up down, left right, meridian, horizon, and it’s always spot on. I was actually marvelling to myself the other night while EAA’ing various galaxies above me, just how solid this thing is. Just another person’s “experience” tho. Cheers…

Thanks for the ASIAIR tip. Unfortunately, it doesn't help me because I am strictly visual and no longer own a camera.

 

As mentioned, I use my C8 Edge/Evo for public outreach. A few club members use SeeStars or other photographic means to show the public things that cannot be seen through one of my eyepieces. However, I am often asked if what is seen through one of my eyepieces is "real time." And judging by the length of time people linger at the eyepiece, as opposed to looking at photographic representations of what is in the night sky, there is a visceral component to visual astronomy that cannot be duplicated by astrophotography.

 

I once was primarily engaged in astrophotography. Visual is relatively new to me. But because of your suggestion, I read up on the ASIAIR and I like what I learned. I have to decide if I want to once again deal with the complexities of "component astro-imaging" (cameras, OAGs, back focus spacers, autofocus, Pixinsight, etc. etc, etc.), or do I want to buy one of the next generation of smart astro-telescopes which will undoubtedly come in larger apertures and with even better AI driven processing algorithms. - Like it or not, the "SeeStar Revolution" is changing our hobby.-- In the meantime, I've solved my Evolution mount problems by adding a Skysync. 

[Tavi]

@mlord,

 

Thank you for your answers. I read the other topic you had suggested (where the wifi related posts here should be moved). I de-solder the L293DD chip and try to power the board without it. The behavior is the same. I must check for other short-circuits, it is almost something else this time. I didn't see any overheating marks on any components. Unfortunately, this kind of troubleshooting is beyond my competence. I don't have yet the dual oscilloscope tester for testing parts in a circuit. 

[mlord]

When I was troubleshooting my own failed Evo, I pointed a thermal camera at it. This identified one of the 3-pin tab regulators as VERY hot. That was the 5V regulator, so I measured the in/out voltages there and discovered it was not working.

Swapped it, and it all came to life. There's a 3.3V regulator near it too, so check that while you are at it.