Sky-Watcher Motor Control Box For EQ5 Pro 20123

[Joharvey]

Hi All

Please could anyone advise if ,  a Sky Watcher Motor Control Box for EQ5 Pro product code 20123 is a direct replacement and would work with the Skywatcher EQ3 Pro Mount ? It looks identical !

Thankyou

this be a direct replacement for my EQ-3 Pro Motor Control Box ? it looks identical ?

[malc-c]

No they are not a direct swap out.  The hardware is the same, but the firmware will be different as the gearing of the mounts are different.  The EQ3 has a gear ratio of 715:1 with 35200 microsteps per worm revolution, whilst the EQ5 has a ratio of 705:1 and 31288 microsteps.... However the firmware can be flashed using the application and firmware from SkyWatchers website, using an EQDIR cable or the handset and a PC-Direct cable.  http://skywatcher.com/download/software/

It's a straightforward process to flash the firmware.   Naturally if you purchased an EQ5 unit, flashed it with the EQ3 firmware and you bricked it you would technically have voided the warranty....

Edited February 27, 2021 by malc-c

[Joharvey]

Many thanks Malcolm for that most informative information. I asked because the Sky Watcher Motor Control Box for EQ5 Pro product code 20123 is relatively easy to source but replacement for an EQ3 Pro is not ?

So for a Skywatcher EQ3 Pro Mount I  identified the file below as matching ?

Firmware: EQ3, EQ5 Pro Goto Mount, Version 2.07

Universal motor controller firmware for Skywatcher EQ3, EQ5 GOTO mounts.

 

 

Many Thanks Joanna

 

[malc-c]

You can rule the first unless the new unit has a USB port.  - It would seem that despite the differences in the mount the firmware is the same.  So in theory you should be able to just connect a new EQ5 box to your EQ3 and it should work right out of the box without needing any firmware upgrade.   It would make sense from a manufacturing point of view for both models to use the same unit.

I would love to know how the handset, or controller knows which mount is being used as the ratios are different... 

[Joharvey]

Many thanks again Malcolm for the information. So for a Skywatcher EQ3 Pro Mount the identified file below is a match. 

But as the Firmware is the same anyway it should work.

That's great. Thankyou Joanna

Firmware: EQ3, EQ5 Pro Goto Mount, Version 2.07

Universal motor controller firmware for Skywatcher EQ3, EQ5 GOTO mounts.

[malc-c]

I've been discussing this on a user group and the consensus is that there may be some subtle difference between synscan units made for an EQ3 and those designated for an EQ5 given the main gear ratio and different stepper motor resolution used.  The opinion is that a designated pin on the microcontroller will be taken high or low and the firmware looks to see the state of the pin, and if it's high sets the value of certain variables to suit the gear ratios for one type of mount, if it low then it sets the variables for the other....  

So to answer your question the two units might look the same, may contain identical boards apart from one or two components that may or maynot be present, and as such are not interchangeable. 

[malc-c]

I was half right.... 

 

Motherboard MC002 for EQ3 PRO GOTO (jumper in JP1 and JP2) / EQM-35 PRO GOTO (no jumper) / EQ5 PRO GOTO (jumper in JP2 position)

So  it uses jumpers to designate which mount the board is to be used with rather than resistors, which would make sense as it means only one production run is required and then the board can be set depending on the customers needs at the time of sale

[Joharvey]

Thankyou Malcolm that's fantastic information.

For a Skywatcher EQ3 Pro Mount , the Motor Control Unit Motherboard  MC002 for EQ3 PRO GOTO requires a jumper plug in JP1 and J2 creating the bridge.     JP2 is for the EQ5 PRO.

Thankyou Joanna

 

 

[malc-c]

You're welcome.

And yes, your board is the later revision (J) which has the two jumpers, which when both are in place designate the board as an EQ3 mount

Just as a point of reference, whilst these boards are quite reliable and can last for years, people have occasionally found an issue where the mount fails to respond and handset reports "Both axis no response".  If you ever get that issue don't throw the board away and buy a new one, drop me a PM as I have the means to reprogram the microcontroller and replace them as detailed in this thread

Most of the boards I've repaired have been damaged as a result of plugging in the wrong connector in the wrong port, and under normal use these boards last for years... 

[Joharvey]

Many Thanks Malcolm for all your help you have been a wealth of information, absolutely fantastic.

Yours Joanna 

[malc-c]

Ignore my message I just sent.  I read your other post and see that your original module was purchased new from FLO just a few months back, so return it and get a replacement under warranty.

[Mollusc]

Hi Malcolm

Thanks for that - sounds very reasonable

I will pass this on to our Committee (!!) and await clearance!

Cheers

 

Graham

[jif001]

I’d like to resurrect this thread if I may. 

I have an EQM35 and the dec motor stutters before starting up on rate 9, and doesn’t manage to move at all at most of the lower rates, basically just twitching, meaning it can’t track in dec. 

I suspected the motor so tried a new stepper only to find it sufferers exactly the same problem. I tried the dec motor on the RA connection and it worked fine, so the motor isn’t the problem. 

I checked all of the solder joints and cable continuity and it’s all fine. That leaves only the control module. 

Sourcing an EQM35 control module seems impossible, but I’ve found an EQ5 module in stock. So, the same question arises - could I replace my EQM35 module with an EQ5 module?

From this thread I’ve understood that the hardware is much the same with some jumpers configuring the mount type. Skywatcher does have EQM35 firmware available on their website. 

Before I blow £120 on it, is it likely to work?

Edited June 25, 2022 by jif001

[malc-c]

16 minutes ago, jif001 said:

Before I blow £120 on it, is it likely to work?

The $64,000,000 question.   Unless someone has done this before we can only speculate.   Googling EQ35M Motor Board throws up images of an EQ3/5 board, so you could assume that it would work in an EQ35M.  However it could be a case of a simple stock image being used rather than the exact one for the 35m.  If your synscan unit has a built in USB socket then that would suggest it used the newer boards based around ARM processors, so the images would be wrong.  Interestingly  one retailer uses the image above with the blue circles....( https://tavcso.hu/termek/MotherEQ3 ) thus proving the point that you can't go by images alone

Best advice would be to post up images of the PCB in your synscan unit (both sides if possible) and compare them to the EQ3/5 board above.  This will confirm which MCxxxx board it is.  However if the board is responding to commands and not giving any "no response" messages then the fault would appear more power related through the drive train rather than related to the Micro Controller.  It could be the supply you are using, or anything from a capacitor braking down to the actual driver chip.  What power source are you using ? - Does using a different supply of the same voltage but capable of providing more amps make any difference?  You could try reflashing the firmware, just in case this has been corrupted, but my gut feeling is that won't make much difference.

You could also drop OVL, the main importer and distributor for SW in the UK, an email and post the question to them.  If they confirm that the same MCxxx board is used in all three models then you might be able to obtain a spare direct from them or via FLO or RVO (other retailers are available  ).  How old is the mount.  Under consumer law you should expect an item to last a reasonable amount of time, regardless of any warranty offered.  If it's just outside the warranty period you may be able to have the mount repaired under consumer law through the retailer you purchased the mount from.

 

[jif001]

The PSU can deliver up to 10 amps and has been running this rig for about 18 months without issue. I have another 10A PSU on an EQ6R-Pro rig that I’ll try just to check though. A connected power distribution box reports 13v. 

I don’t know the retailer or the age of the mount as I bought it second hand. It’s given me good service until now. All I know is that it must be over 2 years old. 

I had a look at the board yesterday just to see if there was anything obvious (broken connection / evidence of a blown component) and there was nothing. When I found this thread I noticed that the picture you posted above (preceded by ‘I was half right’) is of the same board. 

The hand controller reports no errors. With nothing else connected the motors both operate, but the dec motor will only turn at high rates. At low rates it just twitches back and forth.

I’ll do a few more tests today to be sure it is the controller at fault (recheck the connections / try a different PSU /…). I’ll get some pics of the board too. 

RVO have the EQ5 unit in stock, but maybe I’ll try OVL first. 

Edited June 25, 2022 by jif001
Minor correction

[malc-c]

Re-reading through the thread (which I should have done to recap) it seems the same board is used in all three mounts, so yes the one RVO have listed should be a drop in replacement once the jumper has been removed.   I would suggest you try replacing the A3992SBT that relates to the affected axis, but sourcing them from a UK supplier is harder than finding hens teeth.  E-bay have some listed at around £10 each and may take 4-6 weeks for delivery...   Most UK suppliers such as Farnell don't have the DIP packages in stock, and the TSSOP packages have a 365 day lead time !!  

Looks like the only option is to look at getting a new replacement board

[jif001]

Tried a different PSU. No difference. Swapped the cables. Same. No connection problems. The issue must be with the board. 

Pics attached confirming it is the type you posted above.  However, as you can see, there is a jumper in place.

I think I’ll pass on replacing the IC - there’s no guarantee that’s where the problem lies, and my soldering skills are mediocre at best!

I’ll have a go at flashing the firmware. If that doesn’t work I’ll bite the bullet and buy the new unit, then report back here good or bad!

 

[jif001]

Here’s some video - first on rate 9 then on rate 2. When connected to the RA output the motor works normally. 

[malc-c]

That's certainly not sounding right.  The spooling up and down seems to be out of phase.  Fingers crossed flashing of the firmware sorts that out.  

It's certainly an old board. rer I circa 2010, which would suggest this is a board used in EQ3 / EQ5 as there is no jumper for the EQ35M.  You'll also notice that the driver chips on the later revision board shown at the beginning of the thread are the surface SOIC type where your board uses the older DIL through hole type.  Can you confirm the mount you purchased is indeed a EQ35M and not a  bog standard EQ3 ? - Do you know the history of the mount, and if the previous owner has replaced the boards. at any time.

I would drop Ian at RVO an email to confirm which revision their board is, and if it's rev J with the two jumpers then it should be a straight forward swap.

If you do end up replacing the board don't bin the old one.  I'm always after a challenge and it would be fun to have a play about and see if I can get to the bottom of the issue

 

[jif001]

It’s definitely an EQM-35. The M stands for ’modular’ meaning the dec axis can be removed completely turning it into a tracker (Star Adventurer style). As a last resort I can delete the dec axis altogether, although I’m hoping that because the dec motor runs at top speed I’ll still have something of a GOTO function on it. No idea about its history though. 
 

The firmware update is proving more problematic than I expected. Little did I know that the USB port on the handset can’t be used for that. I need a USB(FTDI) to RJ11 connector. The ‘Skywatcher’ labelled ones are (of course!) outrageously priced so I’m looking at cobbling one together out of an RJ11/RJ11 cable I have, and a USB(FTDI)/RJ45.  Just trying to establish the connections needed …

if I end up with a new board I’ll be happy to let you have the old one, but if you manage to fix it I wouldn’t mind having it back as a spare, just in case!

[bosun21]

He’s a photo of my new EQ5 pro control box. They are clearly marked as being EQ5 which never used to be the case. 
 

[malc-c]

You should be able to connect the USB cable between the handset and the PC as it has an in built serial port.  It should show up as a new COM port in device manager.  You may need to change the baud rate to communicate with the handset.  By default 9600 is the speed set, but the other to try is 115,200.  You also need to put the handset into a setting  called PC-DIREC which allows the firmware to be passed through the handset to the mount.

Once everything is connected and powered up the firmware uploader should detect the com port (or manually choose it) and then you should be OK to upload the firmware.

You do not need an  EQDIR cable between the PC and the serial cable from the handset.  Older version that do not have a USB port used a serial cable (that is normally supplied with the mount) and a true serial to USB adapter (ie ones that produce true RS232 levels)  to communicate.  DO NOT use an true RS232 to USB adaptor to connect between the PC and the Synscan unit.  You WILL blow the board for sure.  If you want to replace the handset with a connection to a PC then use the appropriate EQDIR cable

[malc-c]

7 minutes ago, bosun21 said:

He’s a photo of my new EQ5 pro control box. They are clearly marked as being EQ5 which never used to be the case. 
 

 

Your board is also the newest revision which uses the ARM ST processor.  The tell tail USB - B socket gives the game away.

[bosun21]

Have you tried a new hand controller?. Is the motor speed control switched and controlled by the handset or just the speed selection?. This would also account for the lack of error messages. Just a thought.

[jif001]

7 minutes ago, bosun21 said:

Have you tried a new hand controller?. Is the motor speed control switched and controlled by the handset or just the speed selection?. This would also account for the lack of error messages. Just a thought.

Yep. Tried the handset from my EQ6R-Pro. Tried both handsets and both cables in all combinations. No change.