Can I fix my S-3801?

Okay some of my S-3801’s are very twitchy, and others aren’t. If I narrow the problem down to the servo, can I fix the twitchyness? I’ve heard you can take them apart and clean them but I sortof would like to understand more clearly what causes the twitchyness. If the Servo gets yanked around too much I figure it can’t be good, but I’d like to be able to fix it if I can so I don’t have to shell out big bucks for a new servo. Any info would be great.


should you decide to open the case, watch out for the big o-ring that seals the lower case cover. they are easy to damage.make sure it sits in the groove before you tighten the 4 screws

Hi John your twitchy servo can be down to a few things , most prob. is a dirty pot. in the servo these can be replaced by yourself or quite cheap to have it done by a service centre.
The next thing to check is the neg. /black wire from your battery to the switch and on to the receiver and to be just to be sure the servo lead as well.
Especialy if you sail in saltwater, what you are looking for is a black carbon deposit I.E. THE WIRE LOOKS BLACK AND WILL BE DUSTY WHEN SCRAPED below the insulation it is called “black wire” SYNDROME and is very common but more in transmitters that have been left with the battery plugged in and the transmitter not used for some time.
Also check or change your switch or remove it altogether and replace it with a good gold connector male /female.
Hope the above helps cure your prob. I would take a guess and say it is the pot. in the servo.

John,I had the same problem with a Futaba S-125 (3802 is now the equivalent). Took the servo apart and used “volume control cleaner” three times. One time did not do the job. Allow to dry or spray with camera lens cleaner air between each application. The “volume control cleaner” is from Radio Shack (about 1974) and they may not still carry it. That servo worked fine for another 3-4 years. Clyde

Thanks for the info. Will give these a try.

The AMYA website used to have a page on cleaning your servos to remove the twitchiness. But the site appears to be FUBAR. Not sure what’s happening over there…

If the AMYA site ever does come back up, do a quick search and you should find it. It comes complete with pictures showing you just what to clean and how to close it back up so that you do not damage it…

  • Will

Will Gorgen

Well, the AMYA site is back up.

Here is the link to the article:

Good Luck!

Will Gorgen

Thanks again!
God bless the internet!