I recently purchased a used EQ3 Pro, it worked perfectly for 3 sessions and then started having issues with the RA motor, it was jittering and not slewing at low speed but did slew on rates above 7. To make things worse, it would only slew in one direction at higher speeds... I removed the stepper motor and swapped it with the dec motor to check if it was a stepper motor issue.
After fitting the Dec motor in place of the RA it did the same thing.
I opened the Synscan controller and inspected it and found this on the control board? Has anyone come across such an issue before?
Does anyone have a Synscan handcontoller i can borrow to troubleshoot my rig?
I'm in Roxburgh Park, Melbourne.
Any help would be much appreciated,
Thank you!
The images of the rest of the boards(s) would be more helpful for me to give you a better advice.
Your problem is definitely around stepper drivers (RA), because (to my understanding) other functionalities are OK, right?
It could be driver, it could be on-board connector, it could be corrosion on board. Or dried electrolytic capacitor.. list can go on.
I think video could be uploaded if you zip it first.. but the size limitation still remains.
Just an update, I picked a usb A to B cable on my home and connected the mount via EQMOD and Ascom, bypassing the controller all together.
The Synscan wasn't the issue.. I've taken a pictures of the control unit, I can't see anything obvious wrong with it.
Also uploaded a couple of videos of what it's doing.
I swapped the the ra motor with the working Dec motor and the Dec motor did the same thing?
That means motors are OK, it must be the connector on board or the driver IC.
One-direction slewing at only high speed may indicate one of the coils are not energized properly or at all..
I think it is time for a better and deeper look at this.. do you have any specialized electronics equipment, like oscilloscope ?
To replace this chip, specialized equipment is needed, I cant do it (it has a large cooling pad).
However, what can be done is to add this and bypass the faulty IC.. again, it requires steady hand and microscope.
On the attachment, RA driver U1 is a prime suspect, data sheet is on the website
No I don't have any electronic knowledge nor experience with this stuff, where can I take it to have it looked at?
Quote:
Originally Posted by bojan
That means motors are OK, it must be the connector on board or the driver IC.
One-direction slewing at only high speed may indicate one of the coils are not energized properly or at all..
I think it is time for a better and deeper look at this.. do you have any specialized electronics equipment, like oscilloscope ?
To replace this chip, specialized equipment is needed, I cant do it (it has a large cooling pad).
On the attachment, RA driver U1 is a prime suspect.
Data sheet is on the below link.
In case the IC replacement fails, there is an option - to replace the electronics with OnStep, it could be cheaper at the end of the day.
And of course, bypassing of the U1 with this module should be attempted first.
Hi Bojan,
Not really familiar with the options you've suggested, I dropped it off at the repair center in Ringwood today. Waiting to hear back from them.
EQ3 Mount Fixed-Stepper Motor Jittering at low speed
Hi Guys,
Just an update incase anyone else comes across such a problem.
After waiting weeks for the control box repair and then having to order a new one the issue I had was a simple loose cable connection that wasn't apparent due to the wire shielding
the issue I had was a simple loose cable connection that wasn't apparent due to the wire shielding
