Dr_Ju_ju

I've not looked too closely, but I believe the RPi's themselves have an in-built sensor, so following theis may give you the info https://pimylifeup.com/raspberry-pi-temperature/

Yes, it may just be the temperature, I'm having issues with some Arduino focuser's not want to play ball, but if I spray some coolant on them they come back to life....  

Do you have a temperature probe within the RPi box ?  to at least tell you what your facing ....

Cut some decking into squares, and sink a 20-30 mm depression into the centre of each, for the foot spike....

click on this link https://pegasusastro.com/downloads/   then click on the 'software' tab for each of the devices you're after, then click on each of the software links.... you should then be prompted whether you want to run the software or just download it....

Start by tracing the circuit with a resistance/continuity tester & ensure that there are no obvious short circuits on the input and that the incoming 12v reaches the stepper driver chips and  what I expect will be a regulator providing approx. 5v to the control components.

If all appears to be ok, go ahead & apply volts to the board & re-check the incoming and regulated voltages.  

I don't have one, but what I suspect you think is a capacitor is actually an inductor, which might well have blown out if there was sufficient current trying to pass through it....

If you use the auto-focus routines, thay both software packages have, you should be able to re-focus on any filter change, plus periodic changes due to temperature variations etc.

How are you doing the update ??   following the instructions etc at http://www.skywatcher.com/download/software/synscan-v3-hand-controller-firmware/

If you have a scalpel, with a 10A blade, or even a 3d print nozzle cleaning wire, stiff 0.3 mm with a handle, and gently try running it around the button, to see if it releases the grain of sand...

As I replied to your other post, I'd recommend running Mate, which will allow everything to run, but I have to admit I'm having some issues getting LinGuider to work....

I run Ubuntu Mate, which just updated itself to 21.04, & all is running fine on a Pi4 ....  I used this as the source https://www.indilib.org/get-indi/download-ubuntu.html

Silly question, but why not install the ready compiled \ ready to go executables ??  

The ASIAir Pro, is basically a Raspberry Pi4 with a DC regulator to provide the 5.5 volts, required for the Pi and the additional output, while Canon cameras usually need 7.4 volts (both my 600D & 1100d use 7.4v), so you would need an additional DC regulator, to run off the 12 volt supply.    

try running them in a terminal window, not Ekos, to at least check that they work....

not tried it, but enter "shutdown now" or "sudo shutdown now"

As long as it focusses ok, you just won't be limiting the bandpass of the incoming light (https://www.firstlightoptics.com/zwo-filters/zwo-125-lrgb-filter-set-optimised-for-asi1600.html) which may or may not be affected by any specific light pollution you may have locally.... 

At home my mounts are usually power by the 12 volt output from a computer power supply, with no issues.....   When at Star Parties, I use a Maplin linear supply, which has an indent on the voltage control, that sets the output to 13.8 volts, and once again I've never seen any issues..... 

In no particular order:  D-Limonene, Evo-Stick Adhesive Cleaner, Isopropyl Alcohol....  But be careful as some of these are VERY volatile & will quite happily rot away other parts !!

Get a vacuum cleaner (Karcher ?), that can also be used for cleaning cars etc... 

First off which version of Windows are you using ?? 

Then start with the basics, after installing EQMod, & connecting your PC to the mount, open EQMod Toolbox, and in the Setup section "Driver Setup" you first check the Comm Port settings are as per the Windows, Device Manager, Ports settings...

If they are the same you should be able to drive the mount directly using EQMod....  

I would hope that SkyWatcher would provide a driver, that when you connect the PC USB port to the USB-A port on the mount, the mount would then be correctly recognised by the PC, but I'm afraid I can't find one....

So personally, I'd but a USB to serial adapter, and take it from there....

Regular printer cables won't work, you need to have a USB to 'Serial' adapter, as Paul linked to above, which when you have one, can connect to either the handset or directly to the mount (using the port that the hand controller plugs into...)

You must be using some form of interface adaptor between your PC & the hand controller ??  if so, have you set the hand controller into 'Direct PC mode' ?  

And you should be able to connect the device you have connected to the handset, direct to the mount, into the same port the the hand controller plugs into....  & the salesperson is an an idiot, any additional software is freely available....

So what software are you actually using to direct the mount ??   e.g. if you use something like CDC (https://www.ap-i.net/skychart//en/start) connected the mount to the mount does it drive it to the assigned target ?? 

Also try connecting your PC direct to the mount, not via the hand controller...     

Also, if you can, you can increase the throughput speed by partitioning the internal drive, especially my moving the pagefile to a dedicated partition and also a dedicated data partition....