can you help me narrow this problem down??

[sivioke]

So I dug out my old RC truck the other day, its a losi lxt, it has a Futaba FP-r112je reciever, a fatuba MC210 speed control, and a magnum Jr. remote, any way it has been sitting for a few years and I was bored so I dug it out cleaned it up and charged the batteries, it ran fine for a couple of runs but there was no reverse. I fiddeled with the speed control to try and get reverse but to no avail. In the process the car started behaving eraticly. The steering servo will just start twiching, the cars motor will turn under its own will and still no reverse. The wierd thing is when I touch the cars antenna to the remotes antana, all the twitches and erratic behavior stops and every thing starts to respond except for reverse. I think this is strange since 15 minutes before I was racing it in the street. I have followed the speed control directions to a T and know that it is set up properly, at first I thought it to be speed control causing interference or something because reverse is out, but now not sure since I can put both antennas togeterh and it responds fine. So my questions are:

1. Whats is screwed up??? Remote? Reviever? ESE?

2. How can I narrow it down?? I do not have access to any spare parts

Thanks for the help

[tylerbac]

First, change out all the AA batts. Second, check all the solder joints (you said it has set for a long time). Recharge the NiCd Pack and reset the ESC when the pack has full juice. Check to make sure the crystals in the radio and receiver are plugged in all the way (do this with all power off). Use some canned air to spray out receiver and esc. Check motor, make sure brushes are still in good condition.

[highroller]

Maybe setting all that time one of the parts (circuits) in electronics could have corroded if they were subjected to extreme temperature changes or high humid conditions. My hunch is that a circuit in esc has corroded or gone bad the reason you have no reverse (even after resetting esc), iratic servo and motor operation. If you can open the cases of esc do it, and carefully look at the circuits or circuit board for corroded or dark areas. Also check the connectors, plugs on battery pack, esc those may be loose or corroded.

[BCSavage]

crystals?

[sivioke]

Thanks guys I really appreciate the help and the solution!! So like I was advised I checked all the solder points - GOOD then I split open my remote, reciever and esc, then took a can or compressed air and blew all the dust out put it back together and tested it out and can you believe it???? It took me back 10 years, like I just put this thing together !!! You guys rock not only 'cause your smart but also because you saved me from by new electronics! Thanks

[BCSavage]

lol, I like hearing when things work out cheaply :D

[cepwin]

Crystals are how the frequency are controlled on the transmitter. When I got a ham radio license back in the early 70's beginning hams were required to use crystals rather than a VFO (variable frequency occilator (sp?)) in order to prevent them from transmitting in an illegal frequency. Given that the RC transmitters use a very limited number of frequencies it makes perfect sence that crystals would be the frequency control technology of choice. Hope this answers your question BCSavage.

[BCSavage]

lol, I wasn't asking what crystals were. It was a one-word question towards sivioke that maybe he should check his crystals :p he he he

[cepwin]

Well, I guess I've shown not only my age but my nubieness :)