APM 2.5 no longer communicates?

Hey folks,
I’m an admitted newbie with the ardupilot. Got quite far with it and finally started assembling my massive, custom built tricopter this week. When I first got the APM 2.5, I had the firmware installed for a tricopter and the whole thing was working awesome. Plugged it in to my laptop and had the GPS monitoring position while I walked around, accelerometers worked, everything.
Got it installed on the tricopter and powered by two separate BEC’s. It seemed to boot up fine, but yet when I had the laptop plugged in to monitor the setup, it didn’t seem to read any of the radio signals - that fancy screen in mission planner which showed the position of the joysticks showed no joy at all. I also couldn’t get it to do automatic calibration of the ESC’s, though that seemed to me that Ardupilot was doing everything right except passing on the signal through to the ESC’s for calibration.
It would not arm - at all. If I tried to manually arm in MP, I’d get “error: no response from MAV”

I found the note somewhere that AP might be stuck in a loop due to a bad calibration - this was quite likely, so I managed to get in through terminal and erase the EEPROM. I then attempted to reinstall the firmware which went without a hitch. However, it now will not connect through MP. It times out if I install the tricopter firmware. If I install the standard airplane firmware, it’ll connect about half the time. The other half of the time, it will time out as well. It always shows “Disarmed” and the HUD in MP won’t react in any way. I removed the AP from the tricopter and stripped everything off of it except for the GPS. Same problems.

Thoughts?
Thanks,
Ian

@ianjuby,
Since you are using two BECs to power the APM2.5, I assume that one BEC is powering the APM input power rail and one BEC is powering the APM servo/ESC output rail. If that is the case, then have you removed the J1 jumper to split the two power buses? The USB should not be connected at the same time as the APM output bus BEC if J1 is still installed.
Regards,
TCIII Admin

Yes, the J1 is removed. I wasn’t aware of the J1 jumper until I discovered that it wasn’t powering up when I only had the one BEC on the output rails. So since I had just cut off the + on the other two BEC’s, I used one of those to power the input rails.
But the problem I’m running into is even with everything disconnected - USB only, which did work before. Now I can’t connect to the APM at all. It times out.

TIA,
Ian

@ianjuby,
Have you tried using the Terminal Mode and the CLI to see if you can talk to the APM: copter.ardupilot.com/wiki/using- … apmcopter/
Also, some USB ports do not have sufficient current to supply a full up APM when it is connected to the GPS, external compass, etc. You might want to try using a powered USB hub.
Regards,
TCIII Admin

Hey thanks for the input,
Yes, terminal mode works fine. It’ll connect, I’ve erased the EEPROM and reset to factory settings in hopes that maybe it might fix something. I also unplugged the GPS and tried again, though it should be noted that this computer has those fancy high-power USB ports for fast charging of electronics and stuff, and the APM worked just fine on this computer and my laptop before.
Bizarre - I want to say there’s a failure on the board somewhere, but that makes no sense - com works for terminal, it does boot up and stuff. So that doesn’t make sense either - but alas, I’m getting nowhere fast. I may have to get a new board. :frowning:

Ian