AZ-GTI no power

[coldlamper]

I just got it setup. Did 1 star alignment then started slewing to another star. Synscan app lost connection then there was no power light. Wont turn on anymore. New batteries or power adapter make no difference. Is it DOFU? Dead on first use? 

[shropshire lad]

Was it on batteries or power adapter when it died?

 

[coldlamper]

Battery powered when it died.

[malc-c]

Does sound like the mount has died.  Is there any signs of movement on the connector where the power lead connects? - either way I would be contacting the retailer for advice on how to have it exchanged

[coldlamper]

I appreciate the replies.  Go figure but I got tired of messing with it and went to bed. Woke up tried it again and everything worked. Batteries and power supply.  Is there possibly some state the mount gets into where it just needs to be powered down for a while?  Trying to think of possible reasons for my experience.

[malc-c]

14 hours ago, coldlamper said:

I appreciate the replies.  Go figure but I got tired of messing with it and went to bed. Woke up tried it again and everything worked. Batteries and power supply.  Is there possibly some state the mount gets into where it just needs to be powered down for a while?  Trying to think of possible reasons for my experience.

AFAIK there is no shut off system.  The only cause will be a lack of voltage.  Batteries have a tendency to recover for a short period once their output has dropped, and the cold won't help.  My guess is that the output from the battery pack fell below the minimum that the mount requires under load, even when new batteries were installed.  - Best advice would be to use a suitable mains powered adapter

[david_taurus83]

I wouldn't use batteries on this mount as they'd die down pretty soon. Small 12v supply will be better.

[Shimrod]

7 minutes ago, malc-c said:

AFAIK there is no shut off system.  The only cause will be a lack of voltage.  Batteries have a tendency to recover for a short period once their output has dropped, and the cold won't help.  My guess is that the output from the battery pack fell below the minimum that the mount requires under load, even when new batteries were installed.  - Best advice would be to use a suitable mains powered adapter

I would have suspected the batteries as well, but @coldlamper also mentions no success switching to a power adapter when the AZ-GTI stopped working. I'd assume the external power supply would override power draw from the batteries and there is nothing in the manual that says remove batteries before using an external power source.

[AstroNebulee]

I would agree with most here.  I've ever used batteries in mine. At first I did use a talentcell battery pack from amazon and powered the mount nicely for several nights in a row costs around £50but worth it for portability. I now power it all via a 12v 5a mains supply to power the mount AAP and camera. When plugging in the external power source you would of thought it should override the batteries as @Shimrodsaid. Maybe the batteries need to be out before a separate external supply is connected, though I've never tried. 

[coldlamper]

Well experimenting some more I noticed I couldn't slew with the power adapter. Tried a new power adapter and everything seem to be working as expected.  I'm not sure why I couldn't get the LED to come on the other night but perhaps my rechargeable batteries are slightly underpowered and as well as the power adapter so it's hit or miss on powering up.  Lesson learned.  The Az-Gti needs a good clean power source.     

[Carbon Brush]

Unless you measure, power adapters are black plastic lumps that may or may not work well. Leading to results like those you have reported.

May I suggest spending on a multimeter and some bulbs - filament type, not LED.
Buy a handful of car sidelight type bulbs. They are typically 5W or 6W. In other words about 0.5A on 12V.
Measure your adapter output voltage off load. Then start adding bulbs while measuring the voltage.
Read the adapter rating label and compare it to the results on the meter.

Some adapters give a very high voltage off load and drop significantly on load. These are best consigned to the bin.
Some adapters may not deliver what they say on the tin for various reasons. Again, to the bin.

Batteries are another source of problems. Not black plastic, but again unknown boxes if you don't measure.
If you are using AA cells, what sort? Good quality alkaline? Dodgy old stock from the corner shop?
If rechargeable remember that NiCd or NiMH are about 1.2V/cell vs 1.5V/cell for alkaline.
An 8 cell stack of alkaline is 12V, but NiMH <10V. Shutdown territory for some mounts!
Rechargeable sometimes have very iffy performance even from new - are they a known name?
Then all cells are going to give worse performance in the cold.

If you have bought a multimeter, and it has a high current range, like 10A, you can do a (nasty if extended) test on AA cells.
Just put the meter on the 10A range across the cell for a second or two.
The AA cell should deliver around 5A. The short duration load does not eat significantly into the battery capacity.
DO NOT try this test on a powertank or leisure or car battery! You may live to report the injuries sustained! AA cells only.

HTH, David.
 

 

 

[malc-c]

7 hours ago, coldlamper said:

Well experimenting some more I noticed I couldn't slew with the power adapter. Tried a new power adapter and everything seem to be working as expected.  I'm not sure why I couldn't get the LED to come on the other night but perhaps my rechargeable batteries are slightly underpowered and as well as the power adapter so it's hit or miss on powering up.  Lesson learned.  The Az-Gti needs a good clean power source.     

Most  of the standard type of rechargeable batteries (AAA to D cells) normally have an output voltage of 1.2v and not 1.5.  - So the 8 x AA rechargeable batteries will only give you  9.6v  which is well below the optimum 12v required.  Depending on the battery technology, the charge held may drop off suddenly, or the drop off is gradual.  But once each cell has dropped by just 0.262 volts it will be below the 7.5v minimum operation voltage that is stated for an AZ-GTi

Edited April 24, 2022 by malc-c

[fifeskies]

11 hours ago, malc-c said:

Most  of the standard type of rechargeable batteries (AAA to D cells) normally have an output voltage of 1.2v and not 1.5.  - So the 8 x AA rechargeable batteries will only give you  9.6v  which is well below the optimum 12v required. 

Since 8 x 1.2 volts is only 9.6 this makes rechargeable batteries replacing a 12v supply slightly tricky.

One solution is the easily obtained 10x battery boxes designed to overcome this , using a flying 12v lead to plug into the mount 

10 x 1.2 volts is of course 12v , just don't mix in any normal batteries with the rechargeable ones.

 

Edited April 25, 2022 by fifeskies