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Any ideas on repairing a (slightly!) blown motor board ?


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1 hour ago, Paul M said:

I love this stuff!

Much of the PIC malarky goes over my head but I was playing with electronics back in the 70's, 80's and 90's and used to really enjoy fault finding and repairs. 

OC71 anyone? More recently I've been watching the youtube series below, most likely wasted on you guys fixing this stuff but It's reawakened my interest in digital electronics.

Anyway, I really hope your work pays off. It's been a pleasure to follow.

 

 

Nice to hear that you've enjoyed following this thread.  

Whilst my interest in electronics started in 1978 ( when I started my electronics apprenticeship with BAe dynamics, so learnt to solder to ministry spec - although my eyesight isn't what it used to be), In my spare time I was making basic oscillators with BC10x transistors for my father-in-laws model railways, and then discovered 4000 CMOS logic  devices. It wasn't until the late 90's early 2000's that I started messing about with PICs...  Assembly is still way over my head, so when I found you could use BASIC that was the route I followed.  In the past couple of years I've now moved over to arduino and other devices that use that version of C++

Whilst I can grasp the basics, It's nice to have Archie onboard and contribute to expand my learning further.   His knowledge of SW protocol and communications really helps.

I apologies if I go slightly over the top with the posts in this thread, but hopefully it can be used as a reference for anyone contemplating a repair of their motor board.  However if they lack the confidence or ability I'm more than welcome to take on the challenge and increase that "goal score " :)

 

 

 

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Well I've just received a PM from the owner and he's a happy bunny... Yes it's four out of four guys Due to their personal commitments they haven't had the time to put the thing through its pace

Well it's been a busy morning... The SGL member with the damaged MC003 board had a change of heart and contacted me again to see if I would still be willing to attempt to repair  his board.  Natu

We'll it looks like we've scored another goal in extra time The first thing I did this morning was to re-flash the PICs with the same 209 hex file I originally used.  Now as the PICs were solder

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Hi Alan,

Though I trained in Oz, I started at 20th Century Electronics in New Addington, later Centronics Ltd.

My first 'valve' was a quadrupole mass spectrometer tube made by that company.

It was used to measure the exit gas in steel furnaces (originally used in guiding missiles) and my task was to modify it for use in intensive care and respiration.

All gone now unfortunately, but a great and interesting start to electronics.

Cheers

Archie

 

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18 minutes ago, malc-c said:

Nice to hear that you've enjoyed following this thread.  

It makes a change to reading post about pixel poking/peeking etc during this climatic aberration!

Having been raised from birth in my late father's amatuer radio "shack" I've genereally been more at home with analogue circuits but did once design and build an inverter to drive my Fullerscope's mk3 mount's synchronous AC RA motor. It (obviously) ran on 12v with a variable frequency AC output based on a 555 timer. The digital bit came from the crystal controlled frequency readout display. Dividers/counters, shift registers and 7 segment LED drivers etc. It had a joystick hand control to interrupt or increase the output and a potentiometer to fine tune the tracking frequency. It worked, although the output was anything but sinusoidal! Some analogue expert 🤣

I got inspiration for the digital part from the venerable Horrowitz and Hill book "The art of electronics". I could have made something of myself if I'd read it all the way through :)

I had an interview at BAe Preston in 1981, along with 300,000 other applicants for electrical/electronic apprenticeships. I took along a MW radio receiver I'd built on an pin board mounted in an open ali chassis. I loved it although my father said it looked like a seagull's nest. I think BAe agreed with father... "we'll call you...!"

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2 hours ago, Paul M said:

 

I had an interview at BAe Preston in 1981, along with 300,000 other applicants for electrical/electronic apprenticeships. I took along a MW radio receiver I'd built on an pin board mounted in an open ali chassis. I loved it although my father said it looked like a seagull's nest. I think BAe agreed with father... "we'll call you...!"

I would have thought that would have got you in straight away.  The only thing I had built at the time was a dodgy sound to light unit that had a high risk of shoving mains up the amps output if the transformer broke down ! - needless to say I didn't mention that at the time.  I enjoyed my apprenticeship as we had a supervisor that made sure I got a lot of experience in various departments, from the potting shop, the winding shop through to clean air labs where I worked on assemblies for the space and military projects.  I remember one department where a guy drew up a schematic on a sheet of note paper and I was tasked to build it.  A couple of hours later i presented a small bit of stripbaord with the components mounted and they hooked it up to power and a screen.  I had no idea what it was, nor what it would be used for, but whatever it was worked !! - I later discovered it was some form of upscaling circuit, similar to what you see when CSI zoom in to a pixelated image , press a button and it instantly becomes a detailed picture of the suspects car number plate :)  

Taking this slightly off topic, but this was my latest project

 

S2460004.JPG.d9f9b0aa578a0789889a0f823fafbc9e.JPG

 

I started this back in 2009, as a unit that had 4 pulse proportional thermostats in one box.  This latest uint has 9 independent stats, one of which is used for an incubator and sends the temperature and humidity over the wifi so it can be viewed in any other device (web browser) on the network.  I had a lot of help with streamlining my original code that was ported form PICs to the Arduino platform, but then you learn from example.  

This unit controls the heating for my hatchling snake rack and incubator.  I have two more units (without the screen on the left) maintaining the the environment in the nine vivariums housing my collection of pythons, boas and rat snakes.

Anyway, I think we've taken this off topic a tad.....  lets see what the owner of this last SW MC board has to report when he gets it back and tests it... fingers crossed it will be good news :)

 

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14 hours ago, malc-c said:

I've learnt a lot more about these boards, and how they work.

Haven't we all! It's been very enjoyable following this thread. Well done to both of you for persevering.

I currently have 2 new HEQ5 boards - 1 in service and 1 spare (don't ask - a logistics error on my part!) and 1 broken with 'both axis no response'. I swapped out the capacitors to no avail, although it always puzzled me how two power smoothing capacitors could possibly cause that error. If I get some spare time in the new year, I'll try to replace the PICs and get it back in service.

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1 hour ago, Padraic M said:

I currently have 2 new HEQ5 boards - 1 in service and 1 spare (don't ask - a logistics error on my part!) and 1 broken with 'both axis no response'. I swapped out the capacitors to no avail, although it always puzzled me how two power smoothing capacitors could possibly cause that error. If I get some spare time in the new year, I'll try to replace the PICs and get it back in service.

You have no choice now - the converted HEX file is attached :)

HEQ5b.hex

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Well I've just received a PM from the owner and he's a happy bunny... Yes it's four out of four guys :)

Due to their personal commitments they haven't had the time to put the thing through its paces, but it moves inup, down left and right as it should, which I'm chalking up as a result :)

Archie, thanks once again for all your assistance on getting to the bottom of this one... I think that if anymore boards need repairing checking or replacing the diodes might be the first thing to try, and then if that fails look at replacing the PICs as well.  I'll also request the owner to send the handset with the board in future so I can fully test the board before returning it.

 

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  • 2 weeks later...

Hello everyone, I am that happy owner  who sent this badly damaged MC-003 board to Malcolm and received it back in fully working condition :)  I wanted to make a video showing that everything is working as it should,  but unfortunately my smartphone is at repair center now, and the phone I am using now (old Nokia 3310) haven't got a camera :) But I have tested all the SynScan functions and can confirm that everything is just working brilliantly :)  Now just need to wait for clear sky to enjoy it lol :) 

I want to say a massive Thank You!!!! to Malcolm and Archie, for all they did to bring this board back to live :)  You are the magicians indeed!!!! :) 

Mihail

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  • 3 weeks later...

Following on from this thread Synta Electronics I struck up an conversation with the OP  before Christmas... well it looks like I have another MC004 board on its way to me for repair.... Could this be 5-0 :)

I'm hoping this one will be a straight forward swap out of the PICs for newly programmed ones... 

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Well, it 5-0 :)

The parcel containing the two MC004 boards, handsets and cables arrived this morning.  I confirmed the fault (usual - no response both axis).  Removed the PICs and replaced them with two new ones programmed with the 209 firmware.  It was then up to the Observatory to connect the boards to the scopes power supply and test.

P1019390.JPG.7f2b74253acc32ec51754a03020a69b2.JPG

 

Activated the switch and this time no such error.

I was able to press a few buttons and run through some of the settings

setup.thumb.png.1161435d4bf4f32783f3f0d1ed7317d8.png

 

So the kit was repacked and taken to the Post Office to return it back to the owner.  

Must admit this time round this was the smoothest repair so far.  No additional work to repair any lifted tracks etc... just a straight reprogram and swap out of the PICs :)

 

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  • 2 weeks later...

thank you all for this great thread.

I had two broken heq5 boards. for some unknown reason both got bricked suddenly after few months of use between a windows laptop and a raspberry pi.

I am using eqdir cable from FLO.

I Was able to purchase PIC16F886 chips from Aliexpress 10pcs for 10$ + the programmer for another $10. I repaired one of the boards and it is now working perfectly and will try to fix the other one and keep it as a spare.

One of the boards I purchased new from microglobe.co.uk and died four months after. Upon repairing it i found one of the chips to be not glued. there were scraping marks underneath the chip indicating previous glue remove and repair attempt. I don't know if it was done by SW or if item is refurbished and sold as new! I email microglobe twice asking for clarification but still no answer from them.

Screenshot_20210120_193301.jpg

Edited by Aot
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IMO that board had been repaired as was not an original.  All the boards I've repaired in this way have never had the PICs glued to the boards.  As soon as the legs had been cut the package fell off the PCB.

I tend to use RS components for the PICs.  Granted they are not as cheap as Ali Express, but then RS will have paid duty and VAT on them, and naturally are in business to make a little profit.  But they are still reasonably priced at Just under £2 each, and there is more piece of mind buying from them as they are quick to resolve any issues with shortages / delivery / or faulty products.  And for account customers deliver next day.

Glad to hear you managed to sort out the HEQ5 boards.  It's very rewarding and satisfying when you manage to give something a new lease of life and save some money in the process too

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thank you for your reply. I checked RS where i live. unfortunately they required a minimum order of 35pc of that specific chip which totals around 100$ to be customs cleared and delivered. Instead I went for this

 https//a.aliexpress.com/_mKgC5ZF

listing indicates it is an original. they seems ok so far but will see how long it will last!

It is true a very rewarding and satisfying experience for me. I had little knowledge with simple soldering and breadboards i learned few years ago from working with arduino projects. This repair was a whole new thing for me and i enjoyed it.

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Well I have a confession to make... In the course of messing about trying to repair a dead HEQ5 board that a member kindly donated after they had purchased a replacement I blew my own.... well sorta...

I actually blew the EQDIR cable which gave the time out message in EQMOD... but thought it was the PICs that had been blown, so removed the (perfectly good) PICs and replaced them with newly programmed ones... naturally I still got the same time out message with EQMOD as the fault was the cable and not the mount.  Unfortunately in my testing I left a hairline bridge of solder between two legs on one of the PICs which did then burn it out !  It wasn't until I started to test the individual components (EQDIR cable, small connection PCB with wire harness, and the the MBC) did I realise my mistake....

So now I'm waiting for delivery of another bag of 16F886's and an FTDI cable to make a new EQDIR cable.....

As a post note, the original board I was sent to play with was totally blown... Replacing the PICs on it had no effect (and yes after testing I was still able to use my own MBC OK - It wasn't until I incorrectly bypassed an Inductor that I blew my EQDIR cable !!)

I'll let you know how I get on  -  

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On 1/20/2021 at 19:42, Aot said:

thank you all for this great thread.

I had two broken heq5 boards. for some unknown reason both got bricked suddenly after few months of use between a windows laptop and a raspberry pi.

I am using eqdir cable from FLO.

I Was able to purchase PIC16F886 chips from Aliexpress 10pcs for 10$ + the programmer for another $10. I repaired one of the boards and it is now working perfectly and will try to fix the other one and keep it as a spare.

One of the boards I purchased new from microglobe.co.uk and died four months after. Upon repairing it i found one of the chips to be not glued. there were scraping marks underneath the chip indicating previous glue remove and repair attempt. I don't know if it was done by SW or if item is refurbished and sold as new! I email microglobe twice asking for clarification but still no answer from them.

UPDATE

microgloble.co.uk responded with the following:

"Please accept my sincere apologies for the delayed response. These motherboards are supplied to us by OVL. They're the official SkyWacher distributor in the UK. All items we sell are brand new and never opened. Please note that these motherboards are very delicate. They cannot be repaired once damaged, and they've no warranty"

 

It is now hard to clarify if the previous repair was done by SW or OLV!

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That's an interesting response, especially the bit about not being able to be repaired, we all know that's not the case 😉 . 

I don't know how they would go about justifying the no warranty in a court of law.  Having said that, in normal operation they should never go wrong.  It's only when the user connects a 3rd party device, or reverse polarity on the supply that these boards fail and thus any warranty that was offered would be null and void.  Maybe if SkyWatcher looked at adding better protection and isolation on the at risk components then we wouldn't see so many failures.  All I can add is that on the two HEQ5 boards I've changed the PICs on, all have fallen off the PCB once all the legs had been cut, none show any signs of adhesive being used to hold them in place whilst being soldered.

 

Update re: My HEQ5 board

My FTDI cable, connectors and 16F886's arrived this afternoon and after an hour I had my board back up an running.... 

If only I had thought about things logically there was no way my board would have been blown as it wasn't connected at the time.  Still we live and learn !

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I told them i repaired it and it is now working fine :)

i purchased my mount from BH and its board  had both ic glued. I bought it almost 12 month ago. I don't know if the glued ics is a new thing from SW or it is an old thing and they stopped doing it.

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Yes, maybe the glue thing is something new in the process.  Maybe SW are bonding their PICs to the board to prevent these sort of repairs, hoping that in the effort to remove them some of the traces or pads or vias get lifted as well, thus rendering damage to the board? 

Mind you, with the new revisions of boards (mainly with USB sockets) moving away from the 16F886 micro, these sort of repairs may become a thing of the past.  Personally I've not looked into programming the PIC32 or STM32 chips as I've not really had the need to use these devices.  What strikes me is the confusion that may result when someone with one of these new boards tries to update the firmware for the HEQ5 by using the current 2.0.4 firmware coded for the 16F886....

 

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  • 2 months later...
On 06/01/2021 at 13:43, malc-c said:

Well, it 5-0 :)

The parcel containing the two MC004 boards, handsets and cables arrived this morning.  I confirmed the fault (usual - no response both axis).  Removed the PICs and replaced them with two new ones programmed with the 209 firmware.  It was then up to the Observatory to connect the boards to the scopes power supply and test.

Activated the switch and this time no such error.

I was able to press a few buttons and run through some of the settings

So the kit was repacked and taken to the Post Office to return it back to the owner.  

Must admit this time round this was the smoothest repair so far.  No additional work to repair any lifted tracks etc... just a straight reprogram and swap out of the PICs :)

 

Just received this PM from the "customer" :)

Quote

I'm certain that I put up a review here but for some reason it doesn't appear to have been posted!

I received the 2 boards back from Malc-c  in double quick time,  the turnaround was incredible. The boards were fitted and for the first time in probably a couple of years the scope was back to full operational ability. Brilliant service Malcolm, many thanks,

It really pleases me when I read through this thread to know that I've been able to help five SGL members get their scopes back up and running.  But I'm gobsmacked to see this all started almost a year ago ! - where does the time go !!

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