Roll Servo Offline

jnmeade

Active Member
Joined
Oct 9, 2011
Messages
305
Location
Eastern Iowa
I have SV42 pitch and roll servos. Pitch always works. Roll usually is listed in red as offline. When it does work it seems to work correctly. I have verified I have power and ground to the servo side of the DB9 plug. Tweaking, prodding, pushing ,etc. doesn't change anything.
In talking to Dynon, the feeling was a red offline indication in the configuration menu was typically a power problem, but mine doesn't seem to be power. Dynon said if it was a data problem on one of the two twisted pairs it was more likely to present as yellow with the offending pins called out. I never get that.
My next plan is to disassemble the DB9 connected to the servo to verify fully that the pins are correctly inserted and connected, just to lay the question of power to rest.

Any other experiences, knowledge or suggestions?

Again, on the rare occasions that it works it seems fine.
 

GKC Aviation

Member
Joined
Oct 4, 2020
Messages
97
Just be aware, that if you measured voltage with a multimeter, it doesn't mean there is enough current there to drive anything.
I've been caught with this before due to a high resistance through a crimp connector.
Multimeter told me 12 volts was there, but the radio wouldn't turn on.
Put a test light on it (like an incandescent bulb, not an LED), and you will see if it can draw current or not.
 

jnmeade

Active Member
Joined
Oct 9, 2011
Messages
305
Location
Eastern Iowa
I installed DSUB connectors near the servos and wires from there to the airplane were ohmed out OK. I didn't see anything wrong with the DSUB but didn't disassemble it. The plane has been down for several weeks and when I flew it yesterday it announced no roll servo on the ground but when I flew it the notice went away. I was working other issues so didn't pursue it.
The short answer is I haven't located a problem and my guess is it's still intermittent. I suspect a pin issue in the DSUB.
 
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