Blissard 359 Posted February 16, 2020 I recently scored a really nice vintage Futaba FP5-DN set but when I checked inside it was missing the battery, most of the time it's not a problem for box futaba radios because they all use the same battery. So I plugged the battery tray from another Futaba and the transmitter did not turn on even though the plug fits perfectly. After that I noticed that the battery tray has 2 wires only, but the transmitter has 3 wires coming from it. All other box radios of mine have 2 wires coming from the transmitter but the plugs still have 3 pins. Only difference is that the FP5-DN had rechargeable batteries. Do you guys think that the transmitter does not work because of the wire number ? Is it possible to get a custom battery made that has 3 wires if it's going to make it work ? There's a manual for it if it answers anything: https://www.instructionsmanuals.com/product/futaba/radio-control/fp5dn I don't have any electrical knowledge so I don't know what to look for. Share this post Link to post Share on other sites
scoobybooster 248 Posted February 16, 2020 Don't have any personal experience with this transmitter but from what i can read in the manual, this transmitter is designed for the use of 8pcs of rechargeable Nicads. saying: total voltage of the power source should be 9.6V. If you have a try with standart type AA batts, you should try with 6 cells ( 1.5V each -> 9.0Volts) to see if it starts. Or better try with rechargeable AA's then you can use 8 cells which provides you the correct voltage of 9.6V ( accus have 1.2V / each). Better keep your hands of the internal charging system as it is designed for 115Volts AC which is pretty obsolete (we have 220Volts for quite some time now;-) Good luck Share this post Link to post Share on other sites
Blissard 359 Posted February 16, 2020 26 minutes ago, scoobybooster said: Don't have any personal experience with this transmitter but from what i can read in the manual, this transmitter is designed for the use of 8pcs of rechargeable Nicads. saying: total voltage of the power source should be 9.6V. If you have a try with standart type AA batts, you should try with 6 cells ( 1.5V each -> 9.0Volts) to see if it starts. Or better try with rechargeable AA's then you can use 8 cells which provides you the correct voltage of 9.6V ( accus have 1.2V / each). Better keep your hands of the internal charging system as it is designed for 115Volts AC which is pretty obsolete (we have 220Volts for quite some time now;-) Good luck I have just tried 6 cells and 8 cells again but no power. I don't touch any power adapters that come from US anymore, I had few exploded before. Could there be some burnt parts inside the transmitter that I can be replaced ? Share this post Link to post Share on other sites
Blissard 359 Posted February 21, 2020 Does anybody have FN series transmitter here ? I was thinking that FN and DN series might be using same rechargeable battery so I can buy one just for the battery swap. It would be great if anybody have one and take a look inside to check the battery wires. Share this post Link to post Share on other sites
stu22 12 Posted February 23, 2020 Only think I can think of for the third wire is a temp sensor to prevent over charging, but would be very surprised to see something like that on something this vintage. Have you confirmed that the white wire, and the other contacts, are actually connected to the board somewhere and not there just because they pulled a part of the shelf that happened to have it? If it is connected to something you could try connecting it to the ground/negative on the battery under the assumption that the infinite resistance reading it is now seeing is causing it to not work. Share this post Link to post Share on other sites
Blissard 359 Posted February 23, 2020 3 hours ago, stu22 said: Only think I can think of for the third wire is a temp sensor to prevent over charging, but would be very surprised to see something like that on something this vintage. Have you confirmed that the white wire, and the other contacts, are actually connected to the board somewhere and not there just because they pulled a part of the shelf that happened to have it? If it is connected to something you could try connecting it to the ground/negative on the battery under the assumption that the infinite resistance reading it is now seeing is causing it to not work. I have just checked and all 3 wires are going to a small board and there are 3 other wires out of that board going to different parts. I will ask someone to try your recommendation next week, all I can do is change the batteries unfortunately. Share this post Link to post Share on other sites
Jamess 4 Posted March 25, 2020 It looks like an AA cell battery, but requires a few. If you have a battery at home, you can just put it in and try it out Share this post Link to post Share on other sites