Twitching servo

[Peter VintonParticipant @petervinton69315]

hi, I'm new on here and have a problem with my old Sanwa Dash 2 channel rc set. I've used it for many years with a rudder servo and sail winch on different scratch built models but recently the sail winch hasn't been working properly, just randomly twitching rather than driving in or out. I now want to use it on a Fairey Swordsman boat I've been building but when I checked the set I found that the rudder servo, while working fine on channel 1, twitches on channel2. So it looks like the transmitter or receiver is at fault. I don't want to connect it up to the ESC in this state, any ideas if it's redeemable or is it time for a new rc set?

Peter

[Peter VintonParticipant @petervinton69315]

[Dave MilbournParticipant @davemilbourn48782]

Peter

First check that the batteries for both the transmitter and receiver are fully charged. If they have been left idle for a long time they may even be duff, due to self-discharge. Then check that the wiring is sound. Black wires in particular are prone to a phenomenon known as black wire rot. Peel back the insulation a little way and check there is no discolouration of the conductors underneath.
Remove the back of the transmitter and check the soldered joints to the stick pots on both channels. If you can spray some switch cleaner into the pots then do so, and then give the sticks a good wiggle from one end to the other. Check that the aerial bracket is firmly screwed to the circuit board and that the telescopic aerial is also screwed firmly in place.
If none of this improves things then buy a new set; there's no point in flogging such an old horse.
Dave M

[Malcolm FraryParticipant @malcolmfrary95515]

What Dave said, but squirt some of the contact cleaner onto the RX pins for channel 2 as well. If the problem only happens on channel 2, it lets out a lot of the other stuff like power supplies since that has an effect on everything.

I've had pins go a bit wonky due to developing a dry joint in the RX, usually an old one that has seen a lot of swapping around. This needs the RX card digging out of its case to check the soldering on the underside.

[Peter VintonParticipant @petervinton69315]

Thanks for the advice. I've tried cleaning the transmitter pot, I'll try the receiver pins as well and if that doesn't work I'll bin it.

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