I upgraded my 42039 with rc functions by using a sbrick. Since 2 days the servo inside has wierd behaviour. When I steer to the left it gets stuck in the position. It should recenter after releasing the steering but it doesn't. It happens mostly under loaded, when the car is standing or driving on the ground. Sometimes even with unloaded suspension it happens.

Steering to the right works like a charm. Is there a way to fix it or should I call Lego for assistance?

Did you test the servo without any load? If it occurs only under load - there could be too much load / too much resistance or e.g. a beam "hooks in" somewhere so that it can´t get back to center. Another simple guess: a damaged cable which sometimes works and sometimes not (and drives you crazy ). If not, a phone call to the customer service is worth a try.

I know this problem, happened to my servos too. You have to take it apart and file the copper contacts and the metal pin what slides on them with a sandpaper. With time these copper parts gets covered with a layer of who knows what but it corrupts the conductivity. Same applies on rc buggy controller. I've done this on 4 or 5 rc controllers and 2 servos. All works fine. As a side effect it is possible that the treated device becomes slightly lauder.

OK brunojj I disconnected the servo from the steering same issue not cable related.

@Attika: sounds bad my servos are only 3 months old so I would step back from this treatment.

All in all I have to contact tlg support

I know, it should work properly with Sbrick, but have you tried with original Lego receiver, too? The same problem happens? (to all: How much does it count in customer service, if you use third party parts?)

Edited September 4, 20168 yr by Tamas Juhasz

I tested with a lego switch :) and counterchecked with another Servo so I could remove the SBrick as a culprit. I even thought about logging my bluetooth activity wile testing

Then they will send you a replacement servo, it's sure. TLG's customer service is the best.

Edited September 4, 20168 yr by Tamas Juhasz

I'll be callling them tomorrow. Only thing is the massive headache I get, when im thinking about removing the old Servo.

Ok! I called TLG-Support and explained my problem. There solution: Sending a new servo to me and I have to retoure the old one.