HEQ5 Pro Power supply blew

[AlanP_]

Hi,

I finally received my HEQ5 Pro as it was held in customs for over 2 weeks (second hand). I set it all up and plugged it in, but the power supply connecting to the HEQ5 started to 'sizzle'. I then thought it wasn't connected right, so I made sure it was flush but then it blew. This was connected to mains.

I didnt have the 'on switch' flicked on my HEQ5 mount, so I dont think anythign was effectedf inside the mount thankfully. I think its just the box the power supply that blew. I should note, it was rattling a bit when I took it out of the box like something small was lose inside of it. In hindsight, I probably shound't have taken the risk. 

My question is, what is this power supply called? I looked it up but the cable for the HEQ5 mount seems to be different than the one I have. Does anyone know what this is? i'd rather buy something locally as there is a lot of problems with shipping into Ireland atm. 

 

[malc-c]

The mount has been modified by the previous owner.  The standard power connection uses a conventional positive centre female connector.  The thing is that the connector is keyed and if he's been using the mount then there should be no reason for the PSU to blow unless the wires have come away in shipping and ended up shorting inside the mount housing.

The only way to find out of the PSU hasn't fried the motor board is to undo the two screws from below that hold the assembly to the mount and see where the previous owner soldered the wires to the PCB.  If he bypassed the switch then you might have a fried board.

If you can post a picture of how that socket has been wired it would help confirm or deny if further damage is a possibility.  

[fifeskies]

Hopefully the fault has not reached the motherboard.

 

If the output side of the adapter (ie low voltage cable and the "aviation" style 2 pole connector) remain undamaged they can be cut from the damaged supply.

These could then be used with any suitable bench type supply BUT be very careful about polarity.

 

An inline fuse is also a good idea to protect the mount , this can be added to the cable as also shown below.

 

Something like the Maplin supply shown below. (no longer manufactured).

 

 

Edited February 2, 2021 by fifeskies

[StevieDvd]

As Malcom has said, whilst I was typing. this is a user modification, changing the 2.1mm tip to the same connection type that the Skywatcher AZ-EQ5 / AZ-EQ6, EQ6-R and EQ8-R mounts use. It's known as a GX12-2 see https://www.firstlightoptics.com/search/for/GX12-2/

They are not unique to astro so you may be able to get them locally.  I'd be worried about the internal connection being OK and wired correctly even before using the correct cable from reputable suppliers like FLO. If you post a picture I'm sure someone can say if it's correct, and hopefully not blown.

 

 

[AlanP_]

40 minutes ago, malc-c said:

The mount has been modified by the previous owner.  The standard power connection uses a conventional positive centre female connector.  The thing is that the connector is keyed and if he's been using the mount then there should be no reason for the PSU to blow unless the wires have come away in shipping and ended up shorting inside the mount housing.

The only way to find out of the PSU hasn't fried the motor board is to undo the two screws from below that hold the assembly to the mount and see where the previous owner soldered the wires to the PCB.  If he bypassed the switch then you might have a fried board.

If you can post a picture of how that socket has been wired it would help confirm or deny if further damage is a possibility.  

Sorry, what two screws do I open? Not sure what the assembly is!

[AlanP_]

39 minutes ago, fifeskies said:

Hopefully the fault has not reached the motherboard.

 

If the output side of the adapter (ie low voltage cable and the "aviation" style 2 pole connector) remain undamaged they can be cut from the damaged supply.

These could then be used with any suitable bench type supply BUT be very careful about polarity.

 

An inline fuse is also a good idea to protect the mount , this can be added to the cable as also shown below.

 

Something like the Maplin supply shown below. (no longer manufactured).

 

Thanks for the feedback. I may just use the modification that the previous owner did as I dont want to mess with too many things! Hopefully its not fried...

 

36 minutes ago, StevieDvd said:

As Malcom has said, whilst I was typing. this is a user modification, changing the 2.1mm tip to the same connection type that the Skywatcher AZ-EQ5 / AZ-EQ6, EQ6-R and EQ8-R mounts use. It's known as a GX12-2 see https://www.firstlightoptics.com/search/for/GX12-2/

They are not unique to astro so you may be able to get them locally.  I'd be worried about the internal connection being OK and wired correctly even before using the correct cable from reputable suppliers like FLO. If you post a picture I'm sure someone can say if it's correct, and hopefully not blown.

 

 

Cheers Stevie. If its not fried i'll get them locally. When I get it open i'll post a pic.

[malc-c]

Alan,

The assembly that houses the handset connector, power port, switch etc is attached to the mount by two M3 screws that can be found in recessed  holes in the underneath of the housing.

[malc-c]

Fingers crossed the connector is wired to these terminals

[AlanP_]

Here is what it looks like.

[AlanP_]

Here is the backside of it also

[malc-c]

Alan, can you undo the two screws that hold the PCB in place and lift out the board a little as it's not clear how the owner wired in the new port.  It's still not clear.  

[AlanP_]

9 minutes ago, malc-c said:

Alan, can you undo the two screws that hold the PCB in place and lift out the board a little as it's not clear how the owner wired in the new port.  It's still not clear.  

Are these any better malc? I don’t know i can pull it any further bad it’s connected to the port. 

[AlanP_]

I should note, the guy I bought it off had used it with this connection and setup for months without any issues.

[malc-c]

Looks like he desoldered the standard socket to make space and then soldered two overly thick wires (looks like RED for positive and Brown for negative) direct to the board where the old socket terminals went.  Which should mean that with the switch on the mount in the off position there would be no power fed through to the main motor board.  

Sorry you had to pull the mount apart, but at least it confirms things.

[AlanP_]

2 minutes ago, malc-c said:

Looks like he desoldered the standard socket to make space and then soldered two overly thick wires (looks like RED for positive and Brown for negative) direct to the board where the old socket terminals went.  Which should mean that with the switch on the mount in the off position there would be no power fed through to the main motor board.  

Sorry you had to pull the mount apart, but at least it confirms things.

So in other words its all ok? Is the mobo fried?

No worries at all Malcolm, I appreciate you helping me and I was worried something was wrong on the inside and like you said, it things out. 

So, what do I do from here if the mobo is ok? I was trying to find a power solution online but I dont know what to do. This was connected to mains and its what I had planned to do.

[malc-c]

Alan,  It could be just a coincidence, something may have happened in transit, or something else that caused the PSU to blow....you may never get to the bottom of things. 

IMO your main motor control board (MCB) should be fine.  IF the switch was in the OFF position then no power was fed to the MCB.

Right now, with that board off you can trace the positive from the PCB to the pin on the socket and then rewire a new 12v 2.5A power supply  using the same type of two pin plug that Steve linked recommended.  

If you have a digital test meter you could put it on continuity and place the test probes between the two pins on that socket and see if it beeps - If it does then there is a short and the connector would need to be rewired, otherwise plugging in a new PSU will result in it too going pop.  It only needs a stray whisker to cause a short.  Chances are its sound, but just for peace  of mind I would check each stage out before finally throwing the on/off switch

[AlanP_]

I checked the inside of the power box and that’s what definitely blew, as you can see by the picture.

the switch was 100% off. 
Would it be possible for me to just buy a new cable altogether? Not sure if this would work, but if I got this cable: https://www.firstlightoptics.com/astronomy-cables-leads-accessories/lynx-astro-silicone-power-cable-21mm-dc-socket-to-gx12-2-dc-jack.html

And then connected it with thishttps://www.firstlightoptics.com/batteries-powerpacks/lynx-astro-12v-dc-5amp-low-noise-mains-power-supply.html

Would that work? I'd rather avoid doing any wiring myself as I wouldn't be confident with it at all. 

Edited February 2, 2021 by AlanP_

[AlanP_]

Also, is that just a laptop power supply or is it different? I wonder can I pick up one locally.

https://www.firstlightoptics.com/batteries-powerpacks/lynx-astro-12v-dc-5amp-low-noise-mains-power-supply.html

[malc-c]

Alan,

If the two are compatible (best talk to FLO, but they seem so) then yes that would work...., assuming that the socket the previous owner has fitted has been wired the same way as the leads.  IE if the previous owner wired positive to the right pin (as viewed from the front when the assembly has been refitted to the mount) and the supply and cable has the positive feed on the corresponding connection on the plug, then it would be a direct plug and play option.  If the new cable and power supply has it reversed then you would need to rewire the connector on the mount by swapping the wires over..

If you have any doubts then just replace that assembly with a new one  From Microglobe for £39 which has the stock power connector that PSU you linked to would plug straight into.  The choice really is yours, and your ability to test and make any changes that may be required. 

[malc-c]

2 minutes ago, AlanP_ said:

Also, is that just a laptop power supply or is it different? I wonder can I pick up one locally.

https://www.firstlightoptics.com/batteries-powerpacks/lynx-astro-12v-dc-5amp-low-noise-mains-power-supply.html

A lot of laptop PSUs are around 19v.  Some netbooks use a 12v supply ( I use one for my own HEQ5.  It came from an old Asus A900 netbook that developed a fault).  So long as the PSU outputs 12-14v dc it is fine.  Ideally needs to be 2.5A minimum 

[AlanP_]

1 hour ago, malc-c said:

Alan,

If the two are compatible (best talk to FLO, but they seem so) then yes that would work...., assuming that the socket the previous owner has fitted has been wired the same way as the leads.  IE if the previous owner wired positive to the right pin (as viewed from the front when the assembly has been refitted to the mount) and the supply and cable has the positive feed on the corresponding connection on the plug, then it would be a direct plug and play option.  If the new cable and power supply has it reversed then you would need to rewire the connector on the mount by swapping the wires over..

If you have any doubts then just replace that assembly with a new one  From Microglobe for £39 which has the stock power connector that PSU you linked to would plug straight into.  The choice really is yours, and your ability to test and make any changes that may be required. 

Hmm, I might ask him just to be safe. 

Appreciate the help Malcolm. I'll keep you updated.

[malc-c]

It's a shame you are so far away otherwise I would have suggested a socially distanced meeting so I could take a look for you.

If  you want a belt and braces approach you can always disconnect the MBC from that AUX PCB  by removing the connector on the MCB  - the connector indicated connected to the MCB socket as indicated.  This would prevent the MBC from being blown in the event there is a short on the AUX PCB or the socket itself when you power on 

To access the MCB it's simpler to show you this video then describe it

https://youtu.be/hdS5Hisgats?t=94

Keep us posted, and sorry to hear that the experience of getting an HEQ5 hasn't been so sweet  - They are great mounts

Personally, if it were me, and I didn't have the confidence or ability to sort out the wiring I would just replace the complete power / handset / ST4 assembly with the one from Microglobe and get a suitable 12v PSU.  Granted the stock power connector can have its issues over time (often due to the weight of the cable hanging down), which is why some people opt to do the modification you've encountered, but mine has been permanently attached to the mount for 10 years and I've had no issues 

Edited February 2, 2021 by malc-c

[AlanP_]

15 hours ago, malc-c said:

It's a shame you are so far away otherwise I would have suggested a socially distanced meeting so I could take a look for you.

If  you want a belt and braces approach you can always disconnect the MBC from that AUX PCB  by removing the connector on the MCB  - the connector indicated connected to the MCB socket as indicated.  This would prevent the MBC from being blown in the event there is a short on the AUX PCB or the socket itself when you power on 

To access the MCB it's simpler to show you this video then describe it

https://youtu.be/hdS5Hisgats?t=94

Keep us posted, and sorry to hear that the experience of getting an HEQ5 hasn't been so sweet  - They are great mounts

Personally, if it were me, and I didn't have the confidence or ability to sort out the wiring I would just replace the complete power / handset / ST4 assembly with the one from Microglobe and get a suitable 12v PSU.  Granted the stock power connector can have its issues over time (often due to the weight of the cable hanging down), which is why some people opt to do the modification you've encountered, but mine has been permanently attached to the mount for 10 years and I've had no issues 

Your very good Malcolm, appreciate the gesture.

Is there a way to check which wire is positive and negative? Then i'd be more comfortable ordering a new GX12 cable and power brick from FLO and making sure they match up. 

If not, maybe im just better off using a enw one from microglobe.

[malc-c]

You're welcome, like I said, shame we're so far apart.

The best way is with a digital voltmeter / tester.  Place the test leads into the output from the cable when the plug is held in the same orientation as it would need to be to be inserted into the mount.  If it shows -12v then remove the test leads and swap them over  so it reads 12v.  The red test lead indicates the positive supply from the cable.

To confirm that the previous owner used the same sort of cable, change the test meter to the continuity setting, place one of the test wires on the positive pad on the PCB as I indicated above, and the other on the same pin that corresponds to the +12 output form the cable.  If it beeps (or shows 0000 on the display) then it confirms the wiring is OK.  I would also try checking continuity between both pins on the connector fixed to the mount.  If that beeps when you touch both pins then there is a short in that old connector which will need replacing (along with the wires to the PCB)  otherwise you will risk blowing the new power supply as well.

The reason I mention testing the existing wiring is because something shorted somewhere which caused the supply to blow.  The previous owner has used wire that IMO is way too think.  If you look at the wires from the PCB, to the J1 connector that attaches to the MCB as indicated, the brown wire is the 12v feed, and is more than capable of handling the 2 - 2.5A draw when both motors are slewing a balanced rig.

If you are not confident, do you have a mate who is electrically minded, even someone who tinkers with cars should be able to do these checks and even remake the solder joints if needed?

Edited February 3, 2021 by malc-c

[AlanP_]

15 minutes ago, malc-c said:

You're welcome, like I said, shame we're so far apart.

The best way is with a digital voltmeter / tester.  Place the test leads into the output from the cable when the plug is held in the same orientation as it would need to be to be inserted into the mount.  If it shows -12v then remove the test leads and swap them over  so it reads 12v.  The red test lead indicates the positive supply from the cable.

To confirm that the previous owner used the same sort of cable, change the test meter to the continuity setting, place one of the test wires on the positive pad on the PCB as I indicated above, and the other on the same pin that corresponds to the +12 output form the cable.  If it beeps (or shows 0000 on the display) then it confirms the wiring is OK.  I would also try checking continuity between both pins on the connector fixed to the mount.  If that beeps when you touch both pins then there is a short in that old connector which will need replacing (along with the wires to the PCB)  otherwise you will risk blowing the new power supply as well.

The reason I mention testing the existing wiring is because something shorted somewhere which caused the supply to blow.  The previous owner has used wire that IMO is way too think.  If you look at the wires from the PCB, to the J1 connector that attaches to the MCB as indicated, the brown wire is the 12v feed, and is more than capable of handling the 2 - 2.5A draw when both motors are slewing a balanced rig.

If you are not confident, do you have a mate who is electrically minded, even someone who tinkers with cars should be able to do these checks and even remake the solder joints if needed?

After thinking about it, i've decided to just go ahead and order that new part that you linked. I dont know enough about wiring, and its too expensive to be messing around with myself. So i'll buy that and get a new DC power supply from FLO. Really appreciate your help, i'll update this post when its (hopefully) working.