While 1 cell racing yesterday my P/T (AMB) stopped working,light wont come on.....is there a place to send it out for repair? or is it toast

You may not have enough voltage going through the system. Try hooking up a 4cell or 2cell lipo. If the light comes on then you know the pt is still working. If it is then you'll have to hook up a receiver pack or buy a booster to increase the voltage.

As far as repairing it don't know but you can have it cloned.

I had the a similar issues when I put together my 1 cell. When I put the car together with a Novak 4 cell GTB, spectrum and JR 3421 servo the led on the xponder would just bearly glow, with the lights off in my garage. I installed a TQ Voltage Booster worked great a couple weeks at the races.

I have read that quite a few folks are running with no receiver pack or booster but did not want to have any issues so I Installed the Booster.

it worked fine for the 1st few qaulifiers but in the main stopped working...car also seemed off......

Check for a high resistance wire connection, solder or crimp, I.E. receive wires from speed control, or wires to the speed control from the battery, resistance = voltage drop.
We are on the edge, could be the speed control BEC doesn't quite have enough amps at that low a voltage or a connection got dirty or loose. I would not think it is the transponder itself, could be but would not think so.

I would try meauring the voltage at the battery unconnected and then plug it in and check the battery voltage at the speed control.

Another tought, maybe a false change on the battery. If for some reason the battery did not charge, the volts would be low and the car would be slow and the transponder would be likely to not work. just my $.02

Rick I wished I knew about that.
1)What esc are you using
2)what Rx do you use
3)are you using a rx pack or a booster.
4)If you are using a rx pack is it the losi mini t pack if so I know if you are running an LRP esc you have to keep the Rx pack charged and this means charging it between rounds.

The reason I asked about the Rx is we had a guy with a gtb with a fast Rx system and it did not have enough voltage to run the amb trans it was very weak. I know of many myself included have used GTB's without anything and they where fine albeit I run a spectrum RX but for some reason this one would not work. The racer installed a TQ booster and problem solved. I am thinking the fast system requires a bit more voltage and does not leave enough for the amb.

Jim...Im using a 4 cell GTB....no reciever pack...(I run PCM..not sure if this draws more power?)...no power booster......Im waiting on Novak to release thier 'Smart Boost" wich is designed for 1 cell racing...It will act as a power booster and a lipo cutoff......I think Big Mike using the saen as I do and nothing else,,,I know he hasnt had any problems

TQ booster is cheap! may be a good fill in untill the novak comes out!

I suggest you atleast run an RX pack... I ran the booster until it fried then put the rx pack in... 180 mah losi 2c lipo... very small, light, but you need the weight anyway. have had no issues with it.