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


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8 hours ago, chaotic-one said:

 

Okay replaced the ferrite beads, still no go, looks like I lost the programming on the chip maybe

 

If that didn't work, take a look at the 1N4148 diodes on the TX lines of the PICs - If replacing those (see previous posts in this thread where I replaced some using through hole parts) you still get the "no response" message on the handset, or a time out using EQMOD and a EQDIR cable then yes I would agree, the UARTs on one or both 16F886's will have been blown, and replacing them with a reprogrammed PIC would be my recommendation.  Hopefully you'll have more luck than I have at sourcing replacements at non inflated prices due to the global shortage.  I had to resort to contacting Microchip in order to get the last pair of controllers, which took 6 weeks to get to me from the UK.

Quote

also do we know the pinout for the hand controller programming cable, which we did not receive with our purchase?

The RJ11 port is a normal standard serial (RS232) port.  The TX/RX pins are given as 

pinout.png.b9ce5824f286222dddf924fba738dde3.png 

Note that you will need a standard RS232 to USB adapter if your computer lacks an old style serial port - If you use a 5v TTL serial to USB adapter it may not work as the handset is expecting +/- 12v rather than 0-5 signals

A little googling found the pinouts for the Skywatcher serial cable that normally gets shipped with the mount

spacer.png

 

More info

Edited by malc-c
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On 08/11/2021 at 16:28, malc-c said:

If that didn't work, take a look at the 1N4148 diodes on the TX lines of the PICs - If replacing those (see previous posts in this thread where I replaced some using through hole parts) you still get the "no response" message on the handset, or a time out using EQMOD and a EQDIR cable then yes I would agree, the UARTs on one or both 16F886's will have been blown, and replacing them with a reprogrammed PIC would be my recommendation.  Hopefully you'll have more luck than I have at sourcing replacements at non inflated prices due to the global shortage.  I had to resort to contacting Microchip in order to get the last pair of controllers, which took 6 weeks to get to me from the UK.

The RJ11 port is a normal standard serial (RS232) port.  The TX/RX pins are given as 

pinout.png.b9ce5824f286222dddf924fba738dde3.png 

Note that you will need a standard RS232 to USB adapter if your computer lacks an old style serial port - If you use a 5v TTL serial to USB adapter it may not work as the handset is expecting +/- 12v rather than 0-5 signals

A little googling found the pinouts for the Skywatcher serial cable that normally gets shipped with the mount

spacer.png

 

More info

Thanks for all the info Malcom

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  • 2 months later...
  • 2 weeks later...

During the week I was contacted by a member who had inadvertently blown there MC003 board on their goto Dobsonian, and after some discussion as he was in a reasonable travelling distance we agreed to meet up yesterday and I attempted a repair whilst he waited.  Gus brought everything I needed and after a quick chat I set to replacing the PICs I had already programmed.  Gus kept my 18 month old German Shepherd amused playing ball whilst I replaced the two PICs and then tested the repair with the handset, which pleasingly displayed the firmware version rather then the no connection error message.

Gus not only covered the cost of the components and something for my time and expertise which was nice, he also gifted me  a SVBony 105 planetary camera that he apparently had no use for having upgraded.  The generosity of the members I have helped on this thread has really astounded me.  I spent a good couple of hours talking to Gus whilst drinking tea, and he is a real gentleman.... It was nice meeting a fellow SGL member, and being able to get his scope back in action.  I moved away form Luna imaging several years ago, but receiving this camera has encouraged me to swap out the dSLR and give it a go if the weather improves before the moon reaches full. 

I've lost count of the number of scopes that have got a new lease of life curtesy of this thread, but I'm pleased to have been involved in it.  The look on Gus's face when the handset came to life made it all worth while :)

 

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So, imagine the scene, I got a USB lead for my 200P flextube goto as I wanted to avoind having to connect to the synscan app at startup, I got the wrong lead and fried my board. Firstly I tried to contact the manufacturer and various vendors and was told that replacement boards are simply not available. I looked at what alernative options I might have, fitting stepper motors, building something with a Raspberry PI but all left me disheartened. 

Then I found this thread and via this thread the amazing person that is @malc-c After a brief PM session it transpired that Mal would attempt to fix my board for the perfectly reasonable price of £60 parts and labour. Even better he lives 40 minutes from my house. To put this into perspective, Mal rescued my attractive paper weight of a telescope back to a functioning device again. He was able to do this while I waited and played with his lovely dog Juke.

It is events like this that remind me what a great bunch of folks there are involved in this pastime that we all share. 

Can you imagine how many hours Mal has devoted to figure out how to repair these boards? The £60 fee that he charges is not enough because effectively he is saving those of us that need this service retail cost of a new base. The £60 he charges is non returnable as you are paying for his time to perform the repair. There is a chance that the board may be beyond repair but in my case he was able to program two new pics and fit them to my board in an hour. @malc-c I dont have the words to express my gratitude, thanks mate.

So here is my other child back to working again 🍻🎉

 

THANKS MAL

 

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2 hours ago, malc-c said:

During the week I was contacted by a member who had inadvertently blown there MC003 board on their goto Dobsonian, and after some discussion as he was in a reasonable travelling distance we agreed to meet up yesterday and I attempted a repair whilst he waited.  Gus brought everything I needed and after a quick chat I set to replacing the PICs I had already programmed.  Gus kept my 18 month old German Shepherd amused playing ball whilst I replaced the two PICs and then tested the repair with the handset, which pleasingly displayed the firmware version rather then the no connection error message.

Gus not only covered the cost of the components and something for my time and expertise which was nice, he also gifted me  a SVBony 105 planetary camera that he apparently had no use for having upgraded.  The generosity of the members I have helped on this thread has really astounded me.  I spent a good couple of hours talking to Gus whilst drinking tea, and he is a real gentleman.... It was nice meeting a fellow SGL member, and being able to get his scope back in action.  I moved away form Luna imaging several years ago, but receiving this camera has encouraged me to swap out the dSLR and give it a go if the weather improves before the moon reaches full. 

I've lost count of the number of scopes that have got a new lease of life curtesy of this thread, but I'm pleased to have been involved in it.  The look on Gus's face when the handset came to life made it all worth while :)

 

It is actually an sv205 it is this one @malc-c https://www.svbony.com/sv205-astronomy-camera 🙂 thanks again mate.

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14 minutes ago, gusisin said:

It is actually an sv205 it is this one @malc-c https://www.svbony.com/sv205-astronomy-camera 🙂 thanks again mate.

😲 Wow - !!

Thanks once again Gus.  I think we got lucky on the repair in that it didn't involve further troubleshooting after the PICs were replaced...They don't always go so smoothly !!

Just wanted to add that the £60 quoted covered return post via next day special delivery, and even though I offered a lower price as he was bringing the kit with him he still insisted on paying the £60. - Which was really decent of him.

That's a lovely looking rig you've set up and just please to see it action again 

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  • 2 weeks later...
On 13/02/2022 at 15:21, malc-c said:

😲 Wow - !!

Thanks once again Gus.  I think we got lucky on the repair in that it didn't involve further troubleshooting after the PICs were replaced...They don't always go so smoothly !!

Just wanted to add that the £60 quoted covered return post via next day special delivery, and even though I offered a lower price as he was bringing the kit with him he still insisted on paying the £60. - Which was really decent of him.

That's a lovely looking rig you've set up and just please to see it action again 

Did you manage to try out the camera yet? The board is going strong now I just have to work out PHD2 calibration for the mount, haha

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Hi,  Nope not had a chance to yet.  Most of the planets are too low down for me and are morning objects.   Was waiting for the Moon to come back around, and then give it a whirl.  I also injured my back again last week, which makes for opening the observatory rather tricky...  But no doubt I'll get round to giving the camera a run at some point

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  • 3 weeks later...
On 27/02/2022 at 10:44, gusisin said:

Did you manage to try out the camera yet? The board is going strong now I just have to work out PHD2 calibration for the mount, haha

Well looks like tonight will be the first chance.... Combination of health issues and weather delayed things... tonight it's all come together :)

312556766_mooncapture.png.fd1ba566f261a31e15e3b7bf50e3cb44.png

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  • 6 months later...
On 08/06/2021 at 21:28, malc-c said:

Yes, the code protect registers are set in the binary files.  The process of using the PYTHON scripts as mentioned a few pages back to convert the BIN file to HEX and then using MPLAB to change the code protect bits and then re-export the HEX as an unprotected version is required.  But as the code includes the bootloader so the SW update software can recognise the board and upload the BIN file on the fly there should be no need to reprogram them, or try and read back the HEX form the existing PICs.

I was going to suggest using something like GSServer and a true EQDIR cable, but the mount isn't an EQ mount so that wouldn't work as it would still move the scope in strange directions.  

Just in case there was some corruption in the file, I've run through the routine again and produced the attached....  Don't be put off by the MC004 reference - that was due to the previous repairs - there is only one version of firmware for goto dobsonian scopes and that's the 2.09 file, which this was based on.

MC004Final.hex 46.48 kB · 30 downloads

Hello brother

I had the same problem at my skywatcher dob8 with goto(plugged the USB to RJ12 cable from PC into mainboard),but i found the "D3" in my board(photo below)was burned,do you know what is this IC and what is it's size or parameter?

I'm very very very thank you

image.thumb.jpeg.5de9b0797964e3c91df8af3fa3b76998.jpeg

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D3 is a diode that is used in the communications circuit.  A 1n4148 signal diode should do the trick.  If surface mount devices are a problem just bodge it with a through hole variant

Edited by malc-c
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21 hours ago, malc-c said:

D3 is a diode that is used in the communications circuit.  A 1n4148 signal diode should do the trick.  If surface mount devices are a problem just bodge it with a through hole variant

thank you very much,I will buy a new diode

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  • 4 weeks later...

Just to update this thread with another success.  @younghome contacted me via PM for some assistance and over the past few weeks has obtained, programmed and replaced the faulty PICs on the two MC004 boards.  There were a couple of issues that had both me and @ozarchie scratching our heads, but after the second attempt the handset finally communicated with the two boards and the mount is now working fine

 

 

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11 hours ago, DaveL59 said:

now we just need you to figure out a good way to replace failing displays @malc-c 😉 

That does seem to be the next most common problem.... It is sad that Synta forces people in to a position where they have to pay out a lot of money for a complete new handset for the sake of an LCD module that probably cost just a  few $$.  It would be nice if they offered spare parts at reasonable prices for the most common problems.  But I guess they wouldn't make money then.  I mean look at how may motor boards have been fixed by SGL members on this forum for a fraction of the cost of a replacement board or more as a lot of the Dobsonian owners would have needed a complete new base as the new boards are different.  And that is just one forum, there are similar threads running on forums in Europe and the US.

The problem with the display is that it is proprietary.  It may well have a common driver/controller, but the physical shape and size means that it can't be replaced easily with an off the shelf 16x2 LCD display.  If I ever do get a reply from Synta for the cost and process to obtain them then I will post details here 

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  • 4 weeks later...

  Hello everyone,

 First time posting only because of my very basic English but long time reader.

 Anyway, i have probably a silly question. Can I replace a MC003 board of my really old sky watcher autotracking dob with a MC001 board? I managed to blow the board and then damage it even further by letting a friend to try to repair it. The problem is that i can not find the Mc003 anywhere.

Thank you in advance 

Alex L.

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Alex, the two boards are physically different with the MC003 having what has now become standard RJ45 socket for a synscan handset which might make them impossible to swap out directly.  The similarities in component layout between the two boards would suggest that you could replace one with the other.  They both have the same PIC microcontrollers, both have similar connectors for the motors and similar motor drive chips.  However you would need to flash the MC001 board with the MC003 firmware as they are currently programmed with the mount parameters that they are designed to be used in, namely Skymax-127 SynScan AZ GOTO, Explorer-130P, which is not the same as your dobsonian.  Now in theory you should be able to re-program the MC001 with the MC003 firmware used for Dobsonians via the Skywatcher software,  however having never tried this I can't confirm if it works or if it ends up bricking the board.  The alternative would be to reprogram two PICs with the MC003 firmware and physically replace them.

The problem is, as you will have gathered by reading through this thread the new revision of the MC003 and MC004 boards are not backwardly compatible with older dobsonian mounts, so even if you find a supplier of the new revision the chances are it won't fit.  You could contact Skywatcher's Italian distributor to see if they can help.  Their address is 

AURIGA SRL

Via Quintiliano, 30, 20138 Milan, Italy

phone: +39 02-5097-780

fax: +39 02-5097-324

website: www.auriga.it

email: auriga@auriga.it

 

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  Hmm it looks like i am in a deadend, i can't even find information online about this scope. It's just too old and sold for just a short period. I have no hope of finding an exact board. And it's just too expensive to risk bricking a 180 euros board. 

  Maybe the wisest solution is to use the motors and encoders and try to build a go to system with Arduino. I need to study this thing. 

  Anyway! Malcolm, thank you for your time, really generous of you! Cheers 

 

Alex L.

Edited by Saul Goodman
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Alex, you're welcome.

I'm not an expert on these boards, there are people who have done a lot to reverse engineer them and work out the ways to convert the firmware into formats that can be programmed into new replacement microcontrollers.  But most of the motor boards of the same generation all have the same PIC micro controllers, the same stepper / servo motor drivers, and thus in theory could be programmed with any firmware listed on the SW website.  I've never tried it, mainly for the inconvenience of having to then replace the PICs should the board become bricked.

The OP of this long running thread was is a similar position, in that the physical size and characteristic of the new current motor board would not fit his dobsonian, so he would really need to buy a complete new housing in addition to the board, which was more than half the cost of a new complete scope.  As mentioned there are some physical differences between the MC001 and MC003, namely the lack of RJ45 sockets, and the interlink between the two boards.  My guess is that the scope that the MC001 is used with has a separate board with the handset and ST4 port on,  which then connects to the large header pin on the MC001, much like the HEQ5. 

If it were me I would see if the MC001 can be updated with the MC003 firmware, after all at the moment you have nothing really to loose as the scope doesn't work.  If it works then you (we) just need to work out how to interface a handset to the MC001 board and then that should resolve the issue.  The alternative would be to go the Arduino route

Which ever option you choose you need to weigh up the time and cost against replacing your old scope with a new one (or for a complete new mount/base)   

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  • 2 weeks later...

Stopping in to post another successful repair, thanks to malc-c, and some of the things we learned. This is the story of my old xt12g with synta mc004 Rev f motor boards. 

I had the dreaded "no response Azm axis" on the hand controller, leading to a blown pic on my xt12g Azm board (there was actually a hole burned in it). I'm in the US, so sending my board to malc-c would have been pretty costly, so he helped me through the process entirely. I ordered three 16f886's, a 28 pin clip in adapter, a pickit2, and some dupont connectors from aliexpress (tool about 3 weeks). 

I tested every component I could on the boards to make sure nothing else was broken, and couldn't find any other problems than the 16f886. I programmed all 3 pic's with the mc004 209 hex files from malc-c and went to work. I ended up lifting 4 pads from the pcb, lesson learned, don't pry up on the legs. I went back and clipped the legs with my 3d printer clippers, worked perfectly and cut clean. I removed the legs with my soldering iron and cleaned the pads up with solder wick. 

I jumpered the legs that were missing pads to the right connections, and luckily I didn't damage anything beyond that. 

Here's where we really started learning new things. The hand controller still showed the no response message, so back to troubleshooting. I used the uart tool on the pickit2 to try and communicate directly with the 16f886, but got no response. I took a day off at this point because I had been working for hours trying to figure out what I had mis wired to cause the problem. Then today, with the other board, I compared each pin voltage to ground and found that pins 9 and 10 were not working correctly on the new pic. Pins 9 and 10 are the crystal oscillator pins to x1. This definitely explained why I couldn't communicate with the board. I read through the 16f886 documentation to get some baseline knowledge of what I was looking for. I decided to hook the good board to the pickit2 just for fun, and got the 16f886 to communicate just fine. I couldn't read the chip code though because it is protected. At this point I noticed the configuration bits were different than what I had programmed to the new pic. After some reading, the bits set the functions of the chip internally and what pins do what. I decided to test it out, and reprogrammed the new pic with the Alt board configuration bits set. After flashing it, I got the chip protected warning, but I also got the right voltage on pins 9 and 10, me sing the oscillator x1 was on. Checked communication with the uart tool, and it worked, responded back with the firmware version I had flashed. I hooked everything up with the hand controller, and went to the main screen with no warnings! At this point I flashed the 209 firmware through the hand controller to make sure both boards were the same version. The  I tested both boards with the motors just to make sure before putting the scope base back together, both completely working again. 

Tldr: repair was very easy, the 16f886 had to be configured correctly when flashed to work properly. 

The 16f886 firmware hex file configuration bits were set to 3FFA 0700 initially, but need to be 2FA2 0500 to work on the mc004 Rev f for the xt12g at least. 

Thanks to @malc-c@malc-c and this thread that Google found when I ran the search a month ago. My busted xt12g is alive again!

Edited by jmdl101
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@jmdl101 Yes it was quite a learning curve as I had never had that issue with the MC004's before.  Thanks for documenting your experience, and I'm sure it will give others who stumble across the thread the confidence to give this a go if they are in the same situation with a handset reporting the dreaded "No response..." message.  You have also contributed an extra bit of useful information, by testing the OSC pins (9 and 10) with a DVM we can now confirm if the PIC is running with the external crystal rather then the internal 4Mhz one.

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Just wanted to update, my xt12g working better than I was expecting. Stayed on Jupiter for a couple of hours with only needing to bump it once or twice. 

I did learn another important lesson with the encoders, especially the motor encoder. If it can't "see", it won't work. I had accidentally pushed the encoder wheel in too far and it was touching the sensor, so I would push the arrow button but it wouldn't move, or it would jerk around instead of turning smoothly. Goto and high speed rates worked because it would move enough, but tracking and slow rates would not work. After taking it apart and setting the encoder wheel correctly, everything is working awesome. 

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