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HEQ5 - Blown mainboard ?


malc-c
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Hi,

 

I have dropped Graham a PM but thought I would post my problem here as well just in case someone else can chip in (reading up on old posts it seems Graham's the guru when it comes to fixing things)

 

HEQ5 / SW200P in an ROR observatory.  Mount had its main board replaced in 2013, and has been fine until today.  It's powered via a 13.8v regulated bench power supply - Fusion unit

41DjgMxhlqL.jpg

 

The scope was last used a couple of weeks ago - a full slew to check that things were still Ok as it was left standing for around 4 months over winter as I was not able to use the scope due to an injury. It worked just fine.  Today I though I would take a look at the sun and powered up the scope, turned the PC on and connected the scope via EDMOD and CDC - the scope slewed and I was just making small alignment adjustments when I could smell that burning electrical smell, and thought it was the PC, so bent down to check and looked at the PSU to see if it something was drawing too much current - it showed just over an amp, and then the display on the PSU went out accompanied by a pop.

 

I then got a 12v 2amp wall block that powered an old router - confirmed it was supplying 12v and plugged that into the mount.  Switching on I get the usual clunck but no high pitched zinging from the motors.  Thinking I had blown the board I went to shut down the PC and have a cry.... but noticed that EQMod was still displaying positional data.  Powering down the mount resulted in the Time Out Comms failure message, powering back up and the positional data is displayed again.  I put up a post on SGL and Chris confirmed that if EQMod is displaying data, then it's communicating directly with the PIC micro on the mounts main board.  However any command to move the mount, via the PC or gampad fails.  So it would seem that the issue is probably in the driver side of the board.

 

Hopefully Graham will reply and know exactly what component has failed and how to fix it - I'm fairly capable when it comes to soldering.  I would be interested to hear from anyone else who's had a similar issue and if your (graham?) managed to fix it ?

 

Regards

 

Malcolm 

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Guys,

 

You probably already know it, but Graham is a genius.... he suggested I replace a couple of components, and as I had them in a hobby box gave it a go.... pleased to say that the board is now fully functional... just got to put the mount back together after tea....

 

Thanks Graham 

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  • 1 year later...

Sorry to bump up an old thread. I just came across this while searching for the same issue I'm having with my own HEQ5-pro. The error I get on my hand controller is "Caution: both axes no response". The EQMOD cables are also not able to communicate with the mount. I just recently started getting into this hobby and this has been a huge bummer for me, especially since it's the best time to photograph DSOs here in Canada. I see that replacing some components helped fix the issue, could someone please let me know which components might need replacing.

Also, wondering what might be causing these boards to blow up in the first place. In my case I was trying a new DIY eqmod cable (I already had a working one). I also left my mount outside in the backyard for few weeks covered in a plastic bag and it worked just two days ago. As far as I could tell the EQMOD usb cable was wired properly, can this even blow up the motherboard?

 

I would really appreciate it if someone can help me fix my mount.  Thank you!

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Hi there. 

I will send you the details of which components probably need replacing when I get home from work today. 

They are the 2 large black capacitors top left of the board next to the cable sockets. 

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  • 6 months later...

Sorry to bump this post.

 

I am getting the "No response - Both Axes" message on the SynScan unit on my HEQ5 mount.  I am 99% certain it is the main board. I'm quite happy around electronics but I do need a guide as to how to get at the main board.  Any guides out there?

 

Chhers

 

Phil

Edited by PP51
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Undo the 4 screws that hold the top cover on the mount.

Remove the cover and you will see the main board inside the mount.

Remove the wires from their clips.

Undo the mounting screws and lift the board out.

If yours has the fixed wires to the input board and cannot be removed via clips then undo the 2 screws from the cover where all the cables plug in.

Very carefully lower the cover and unplug the leads connected to the mother board.

Be very gentle with it as the solder connections on the input board are very small and fragile.

Edited by Graham
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Many thanks Graham.  

 

I have a slightly different screw layout on my HEQ it appears.  I bought it a couple of years ago from Rother Valley Optics and went for the version with the Rowan Belt Mod.  Not withstanding that there were three screws on non motor side and, once I had removed the belt drive cover (six screws) there are two further screws to remove to remove the top cover.

 

After that it was fairly straight forward.  A few photos on the camera to remind me where the cables went I removed both motors, replaced the main board and re-assembled.  All-in-all about 45 mins.  Back working again.  Can't see any obvious problems on the original board - no sign of burning or smells.  No obvious way of testing it as far as I can see.

 

Once again - many thanks

 

Phil

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If it has had the belt mod it would be different.

The 6 screws and the extension piece is part of the belt mod kit.

Glad you have got it sorted.

 

Did you try replacing the 2 caps I outlined in the original thread.

These are the normal culprits and will not show any sign of failure.

Edited by Graham
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Sorry I did not see that you responded to my original question Graham. Thanks for responding to it with help. I finally got around to replacing those two capacitors with 35v 470uf ones. However, I am still faced with the same issue and no other visible defects. Are there any other components that might be worth replacing? 

 

thanks,

Supun

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To tell you the truth I have a board here I have been working on for a couple of years on and off and I still cannot find out what is wrong with it.

I swapped it out for a new board and the mount works fine.

So the issue is on the board but can I find it can I heck.

I have swapped out most of the components on the board and it still refuses to work.

I will sort it out one day, it has become a challenge for me when things are quiet. 

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Thank you, I guess I will go the route of replacing the board. My concern is that I still don't know what fried it in the first place and I'm worried about repeating it again with the new board.

 

But if you ever get your old board working let me know on the off chance I'm having the same issue.

 

 

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Hi, an astro newbie here who had a disastrous night last night. My HEQ5 Pro mount (with belt mod) has stopped working with a 'Caution - Dec/Alt, no response!' error on the handset. The handset wasn't attached at the time as I had just finished using SharpCap for Polar Alignment and was attached to laptop via Prolific USB cable ready to use PHD2. I think I had a small short on the power cable from my battery pack to the mount as I saw a brief flash at the mount end. When I examined the cable, the wires going into the plug had slightly come out of their screw in contacts and so probably touched.  I fixed this, but couldn't then connect to the mount via EQASCOM on the laptop. So I plugged the handset in and got the above error message.

 

I have tried different power cables and handset cables and run off the mains as well as my battery pack but with no difference.

 

Is there any way the mount could have been put in a state which is recoverable by a software on the laptop or a hardware reset? I have reset the handset to factory settings but it's no different. Or is it the worst of my fears, that the motherboard will have been blown somewhere by the short.  I've opened up the case to find that the motherboard is secured by two screws in quite an inaccessible position.  Do I really need to remove the motors to take the motherboard out?  Any help would be really appreciated as I'm desperate to get started again.  

 

Many thanks in anticipation.

 

Martyn Jones

Edited by GeekTeacher Astro
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Yes you will have to remove the motors to gain access to the motherboard mounting screws

First thing I would check is the power socket.

Does the red led come on when you power up the mount.

Remove the 2 screws from the cover holding the sockets where all the leads attach.

Very carefully lower the cover taking care not to put any stress on the leads inside.

Edited by Graham
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Does the mount work using the handset ? If your eqdirect cable is the old prolific chipset I would look at getting a tdfi version 

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1 hour ago, Bottletopburly said:

Does the mount work using the handset ? If your eqdirect cable is the old prolific chipset I would look at getting a tdfi version 

Mount does not work on the handset David.

 

Quote -- "So I plugged the handset in and got the above error message.

I have tried different power cables and handset cables and run off the mains as well as my battery pack but with no difference."

 

 

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My handset has a USB PC interface (rather than the older RS232 interface) and I get that message when I connect the handset to the PC before turning on the control unit power (the handset is powered from the USB bus under that condition). So, if your handset is being powered soley from the control unit then it doesn't sound like a power supply problem, rather a fault causing a failure of the serial comms interface between the handset and controller, but without a circuit diagram, your guess is as good as mine.

 

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Just noticed that your problem seemed to have occured after a short on the power supply (3 different threads in this post). The only thing I can think of is if the circuit has a linear regulator that drives a significant capactive load, then a short on the power supply would reverse bias the regulator which could result in its failure (some types have internal protection, others require external protection to be fitted). Just a thought ...

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  • 4 months later...
On 18/05/2020 at 12:45, Clive said:

My handset has a USB PC interface (rather than the older RS232 interface) and I get that message when I connect the handset to the PC before turning on the control unit power (the handset is powered from the USB bus under that condition). So, if your handset is being powered soley from the control unit then it doesn't sound like a power supply problem, rather a fault causing a failure of the serial comms interface between the handset and controller, but without a circuit diagram, your guess is as good as mine.

 

 

 

It would seem this was my issue. I plugged it into USB first. I unplugged it for a bit and when I plugged it back into mount, all seems well. Thanks 

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  • 1 year later...

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