Hey guys,I have an old Futaba Magnum Jr FP-t2pka radio transmitter. I last used it about a year or so ago and stored it in a climate controlled area.
This year I went to use it and placed good working batteries in it and found it doesnt work. I checked the batteries with a Digital Multimeter and all batteries are good. I flicked the power switch again and the voltage meter needle doesn't move. I tried the batteries in another transmitter and it worked. I went back to the non working transmitter and took the case apart. Plug the batteries into the slot and checked to see if I had power where the red and black wires are connected to the contacts. I do have power there. But this is where I need someone with electronics knowledge to lend a hand to guide me on how to check other things with the DMM to find out what went wrong with it.

Anyone that can help with this? I dont want to discard the piece as its for a vintage r/c car that I want to keep running a nicd pack through. I would like to use it as a project on how to fix something electronic. I looked for the schematic but cant seem to find it online. I suppose due to the age of it.

I found the manual here.https://www.manualslib.com/manual/378247/Futaba-2pka.html

 

I would try exercising the power switch numerous times. It looks like a slider type. Switches often have silver plated contacts which can form hard non-conductive surface compounds such as sulfides. Slide switches are usually lubricated with a light grease and the grease can cause problems with age (oil and soap separate leaving hard soap where it interferes). There are contact cleaners that can help, but they can also completely strip the lube. If a suitable replacement can be found, replacing a switch is sometimes the quickest and easiest solution.

You can confirm if the switch is making contact by measuring the voltage across the contacts. It should be zero (a few millivolts is OK) when ON and close to the full battery voltage when off.

 

Thanks Ill give it a try and seek the switch out.