Odd Power LED Flashing on Skywatcher NEQ6 Pro

[Gib007]

Hello everyone, this is for a friend of mine having issues. He has a Skywatcher NEQ6 Pro mount and has had the electronics board on it replaced before. The issue he is having at the moment is the power LED flashing. This is a tell-tale signal of low operating voltage. When I used to have the same mount, I used a DC-DC Converter that produced a regulated 15V supply from my 12V Marine Deep Cycle battery. All was good and I never had problems, even with my CCD camera running off the same battery - the mount always received a clean 15V supply. 

My friend has the exact same setup though. A 12V Marine Deep Cycle battery that has been recently charged over 24 hours, with the same DC-DC Converter I used to use. Without anything else on the battery, just the mount, the power LED flashes constantly at the 15V setting. We've tested that indeed 15V is coming out of the DC-DC Converter by use of a multimeter. The battery's fresh voltage off its terminals is around 12.5V. Both voltages are stable so the mount is receiving a clean regulated 15V supply. Because of this flashing power LED, EQMod will appear to connect to the mount but the mount doesn't initialise so it doesn't respond to any EQMod commands (for slewing, for example).

My friend increased the voltage coming out of the DC-DC Converter to 17V and still nothing. Next, 18V - nothing. When we reached 19V or so, suddenly the power LED stopped flashing and the EQMod connected to the mount flawlessly and it worked. We confirmed the DC-DC Converter was outputting around 19V. Please keep in mind there was nothing else on the battery - just the mount!

Now, I'm aware these mounts' electronics boards are meant to take up to 15V maximum, hence the setting I used to use on mine that worked perfectly. I genuinely have no idea what is causing my friend's NEQ6 Pro to have this issue but I suspect it's his electronics board on the mount. We tried his mount with my own 12V Marine Deep Cycle battery, DC-DC Converter and cables, just to make sure it's the mount that's to blame. Mine are known to work as I use them often for imaging. 

Anyway, any pointers/suggestions would be fantastic as this issue is persistent. Thank you in advance!

[steppenwolf]

Can you please confirm that the voltages measured from the DC to DC converter were 'on load' not 'off load'?

[Gib007]

Can you please confirm that the voltages measured from the DC to DC converter were 'on load' not 'off load'?

The voltage measured from the DC-DC Converters (both, mine and his) were measured straight off the tip of the connector with a multimeter while the DC-DC Converters were connected to the battery. We couldn't measure the voltage when going into the mount due to not having access to the connector once connected into the mount. I do the same with mine though. I confirm 15V is coming from the tip of mine and just pop it on to my mount and it works. My friend is having no such luck though. 

[steppenwolf]

The voltage measured from the DC-DC Converters (both, mine and his) were measured straight off the tip of the connector with a multimeter while the DC-DC Converters were connected to the battery.

OK, this is not a reliable indication of the voltage being received by the EQ6 under load and it could well be that although the converter is working fine with your mount, your friend's one is drawing more current (load) than yours and the voltage drop is too high - there could be many reasons for this and not necessarily indicative of a fault as such. So much depends on the rated output of the converter because if it is on the edge of delivering the required current, a small increase in load could drop the on load voltage too low which is what I suspect is happening here.

Have you also tried powering the mount from a freshly charged 12V Marine Deep Cycle battery? If it is in good condition, this should have next to no voltage drop and should easily power the EQ6 with no flashing LED.

[Gib007]

OK, this is not a reliable indication of the voltage being received by the EQ6 under load and it could well be that although the converter is working fine with your mount, your friend's one is drawing more current (load) than yours and the voltage drop is too high - there could be many reasons for this and not necessarily indicative of a fault as such. So much depends on the rated output of the converter because if it is on the edge of delivering the required current, a small increase in load could drop the on load voltage too low which is what I suspect is happening here.

Have you also tried powering the mount from a freshly charged 12V Marine Deep Cycle battery? If it is in good condition, this should have next to no voltage drop and should easily power the EQ6 with no flashing LED.

Thanks for your help. You're probably right on the mark with this. Please note the DC-DC Converters being used produce regulated voltages however. Moreover, we've tried the mount on two freshly charged 12V Marine Deep Cycle batteries (his and mine, and I know mine works for sure as I use it regularly for imaging on my own equipment). 

Also, the power LED flashes even before we connect the mount to EQMod. As soon as you flick the on/off switch to on, it starts flashing. This is without slewing, without the SynScan Hand Controller, without EQMod or any activity whatsoever. It only stops flashing when we tweak the DC-DC Converter's output voltage to around 19V or more. 

[steppenwolf]

Also, the power LED flashes even before we connect the mount to EQMod. As soon as you flick the on/off switch to on, it starts flashing. This is without slewing,

The fact that your friend has already replaced the controller board is a possible indication of high current drain caused my a motor fault perhaps? I'd be tempted to remove the side-plate and pull each of the motor plugs off the controller board in turn (with power disconnected) and see if one of these is causing the problem - the only problem with this approach to diagnosis is that for the life of me, I cannot recall whether or not the LED flashes to indicate a disconnected motor!!! It has to be worth a try though.

[Tinker1947]

You can check the mount voltage on the handset, then slew the mount and keep a eye on the voltage out put on the handset.....

[Gib007]

The fact that your friend has already replaced the controller board is a possible indication of high current drain caused my a motor fault perhaps? I'd be tempted to remove the side-plate and pull each of the motor plugs off the controller board in turn (with power disconnected) and see if one of these is causing the problem - the only problem with this approach to diagnosis is that for the life of me, I cannot recall whether or not the LED flashes to indicate a disconnected motor!!! It has to be worth a try though.

That's a good suggestion. I will speak to him about it. He told me that he had to replace the circuit board because the mount wasn't giving power to the SynScan Hand Controller, so Ian King sent him a replacement circuit board. 

You can check the mount voltage on the handset, then slew the mount and keep a eye on the voltage out put on the handset.....

Yup, yup. We just didn't have the SynScan Hand Controller at hand. We were using EQMod all the time. Will try that tonight!