HEQ5 Pro - handset becomes unresponsive

[christiano]

Hi all,

I recently bought my HEQ5 Pro second-hand and it seemed to work fine. It has the SynScan handset which I upgraded to the latest V3 firmware, I think that’s the highest firmware it will support.

When in use, after a while pressing buttons just does nothing although after a several minutes it comes back to life, sometimes slewing for a while and once I had to switch it off as the OTA was going to hit the tripod!

I did lots of internet research and as I had been using a battery pack I changed to power the mount from the mains, but it still happened.

So I have two things to try but thought I’d see what you guys think:

1) I could clean inside the handset with isopropyl alcohol

2) I could try and keep the handset warm

Anything else?

Thanks in advance!

Christian.

 

[Varavall]

Hi Christian

If the problem occurs whilst the handset is in your hand, I would check the security of the cable connection at both the handset and the mount (I had a poor connection once), and maybe closely examine the cable for deterioration. Maybe that helps.

Adrian

[christiano]

Thanks; I’ll do that now. 

[AstroMuni]

12 hours ago, cadoran said:

When in use, after a while pressing buttons just does nothing although after a several minutes it comes back to life, sometimes slewing for a while and once I had to switch it off as the OTA was going to hit the tripod!

I did lots of internet research and as I had been using a battery pack I changed to power the mount from the mains, but it still happened.

Have you tried this in daytime inside your house? Does it still misbehave? That will help rule out if its because of dew or cold.

[christiano]

1 hour ago, AstroMuni said:

Have you tried this in daytime inside your house? Does it still misbehave? That will help rule out if its because of dew or cold.

Brilliant idea! I’ll try that now.

BTW I have checked the cable (I have an RJ45 cable tester) and it seems fine even if I move the wires around the sockets. Visual check okay too although where the block clamps over the cable it looks like the cable outer covering was slightly pinched, have hopefully put it back a bit better. Still tests okay after.

[Carbon Brush]

Yes by all means check obvious physical connections first.

But there is a potential issue with all of the handsets - not just Skywatcher.

The buttons are basically a bit of conductive rubber (yes it does exist🤔) that is pushed onto the printed circuit board to make the contact.
This is not a 'zero ohms' contact like a switch. The electronics is looking for a high resistance vs open circuit.
Several things can happen to make this go wrong. Just which mechanism comes into play depends on the handset.

First a dew problem on the circuit board. You get a bit of conduction on the mosit board - just where you don't want it.
The circuit can't decide wheher it is button on or off.
Make sure the PCB is clean and dust free. That makes condensation less likely - and less conductive.
Consider whether parts of the PCB could be better insulated. Though usually the (often green) solder resist takes care of this for you.
Connector pins may still be epxosed. Consider a bit of laquer here.

Second the conductive rubber degrades so a button doesn't always make contact. Though it is not often seen on decent quality kit.
The symptom here is that a button press is ignored. Or you have to push and waggle a key.
It is often accompanied by bits of button snadwiched between the circuit board and keypad - back to cleaning.
You can buy conductive ink to recoat the keys, but it is a temporary solutuon.

Third the printed circuit board is loose. It is not in close contact to the keypad.
A previous dismantler may have left loose screws, or lost some, or some case plastic may be broken.

Find yourself a clear table top and a pot for all the little bits that get lost and take the handset to pieces.

HTH, David.

 

[christiano]

1 hour ago, Carbon Brush said:

Find yourself a clear table top and a pot for all the little bits that get lost and take the handset to pieces.

Thanks; I’ll do that.

The mount (no scope etc.) has been switched on indoors for 90 minutes now, I’ve navigated to a number of targets and have not had any problem yet.

I’ll give it another hour or so then switch it off and take the handset apart!

[christiano]

The mount was still fine after 5 hours indoors (took the dogs for a walk).

Screwdriver next!

[bosun21]

Either the screwdriver or put a plastic bag over it when it’s not in use to prevent the dew ingress.

[christiano]

Sounds good 👍