DSR 922 Motor Circuit bad

[beemerdoc]

Hey All,
I have a 922 that had the actuator lock up, and now the M1 and M2 terminals do not produce any voltage to move the dish. I took a peek inside, and I do not see any circuit protection for that. Is there any info out there that can help me diagnose and repair the circuit? I am a tinker of many things, and am not afraid of a VOM or solder gun.
Thanks for any help in advance.

 

[tvropro]

There is a TVS that is located on the actuator supply pcb that go bad. I believe the part # is CR104

Here is a link for the part:

1.5KE51CA-E3/54

You can clip one end of the leads if it is shorted to see if it restores operation. If it does get the new parts before using it for regular service.

The pictures are for the 920 and were found on the net.

 

[beemerdoc]

Thank you, Kind Sir!
I shall remove the cover this evening and see if that is indeed the culprit.
If I could figure out how to send a cold one across this screen, it would be for you!
Have a great day!

 

[tvropro]

Hope it's the culprit. The circuit seems pretty simple.

 

[beemerdoc]

Well,
RATS!
Removing the TVS diode did not allow the circuit to function. Would I be correct; one could use the diode check function on a VOM and get no passage either way? I don't. I did run into a Dinosaur TVRO guy here that is going to let me have some old 922s to play with, maybe I can switch out the entire rectifier board and get it back up.
I will keep digging.
Thank you again!

 

[tvropro]

Is there voltage at the input and output of the bridge? Is the bridge rectifier shot? The circuit is pretty simple. Vcc through bridge feeding a couple relays. A few protection devices too.

You should check the caps and other parts for any signs of short, value change etc. If your going to get another 922 with a known good board in it then I would do a swap. If that don't fix it the issue, it's looking like a logic control problem. If that's the case you would be better off to ship it to ATS. To answer your question about the TVS if it was shorted when you clipped it from the circuit the thing would work as long as the logic circuit is good.

One last thought... I seen this happen before, I don't know if you did it yet? If not do a master reset of the receiver. A clients system I worked on had a bad actuator. After we swapped it it wouldn't move so I did a master reset and eveything worked.

 

[beemerdoc]

Well, I did a master re-set, and nothing new. I swapped out the board and everything is fine now. Thanks for your help in the matter.
I will send the broken unit to ATS and have a spare for next time.
Here's to Health! :up