Celestron 127 SLT Problem

[john2y]

Hey guys, 

recently I've bought a new Celestron 127 SLT and I was really excited to try it out. First night was good but I couldn't align it. Second night I had no problem with alignment but after about one hour of tracking the Moon I wanted to change the tracking to Jupiter but the remote seemed to be stuck and I couldn't control the telescope at all. I turned it of and on again and when I tried to align it (using auto two star alignment) I've centered Arcturus and when the telescope started slewing to Vega it misted it and just continued rotating and again I couldn't stop it or control it other way. So another restart of the telescope and this time, the little display on the remote suddently turned off. Any time I switch it on is gets either stuck or moving uncontrollably. Basicaly my telescope went crazy and I have no idea how to fix it. Do you guys have any idea or should I just send it back for warranty repair?

I was using power brick to power the telescope and I had the batteries from the previous night still inside but I don't think that thats the cause of the problem.

[DRT]

Many of the problems experienced with these mounts are due to the power supply. I'd suggest you buy a new set of alkaline or lithium AA batteries (not rechargeable batteries as they have the wrong voltage) and try again without your power brick.

[Chris]

Hi John, what voltage and Amps is your power brick, also is it a regulated supply?

As Derek said, most issues are due to power supply.

[ronin]

That does sound very much like reports of low voltage/power at the scope. I get the impression that although rated at 12v that 12v is the lowest they will operate with, a small amount more is often beneficial but be careful as often no protection in the electronics.

For batteries I always use new ones and expect about an hour from them. Do not use rechargeables as they are 1.2v not the expected 1.5v. Not sure about shops where you are but here there is Poundland and I will visit and buy two packs of 6 high power batteries for mine - mine is 9v not 12v. At £1 a pack they are sort of ideal to put in use and then dispose of.

What appears to happen is the power drops but is sufficent to illuminate the handset and maintain the tracking rate. When asked to do any more then the scope just has insufficent power to perform the required action.

[Cosmic Geoff]

The symptoms are consistent with bad power. See the "GoTo FAQ" post for a solution.

 

[jambouk]

Make sure one of the rubber buttons isn't stuck slightly under the plastic caseing - this happened to me.

James

 

[john2y]

Thank you guys, I'll try it. I have 12V power brick so I'll just throw it away and use batteries. It didn't occurred to me that it could be the cause. 

[Geoff Lister]

I have a Skywatcher Skymax 127, so it should be similar to yours. I normally use it with a 12V 2A or 12V 1.5A plug-top supply without any problems. I have also used batteries, 1.5V alkaline, and, with a holder for 10 cells (instead of the standard 8) NiMH rechargeables.

I have done a few current measurements, and the mount takes about 90mA when static, 160mA when tracking, but 350mA when slewing.

If there is a poor contact anywhere in the supply chain, including the individual contacts for each cell in a battery pack, then the voltage is going to be lowest during that slew to Vega.

Don't throw away your power brick until you have checked all other possibilities.

Geoff