Problems with my FG085
Posted: Thu Jul 28, 2016 7:15 am
Ok, I suspect I may have caused some of these. As noted elsewhere, I managed to screw up the power switch, and then managed to strip the rings off the through holes for the switch installing the replacement. These may or may not have contributed to my problems.
Checking the schematics, I added a jumper from what I think was pin 6 (the pin closest to the corner the switch is near) to pin 1 of U2, and another from pin 5 (adjacent to pin 6) to positive output of DB1. Pin 4 is shown as disconnected. Since the unit powers on and mostly works ok, I believe those are right.
But the other pins I have no idea what to do with. I can see that I should run one line from the other output of DB1 to pin 2. But it's shown as being wired to the two sides of a pair of LED (D10), and I don't see anything that looks like that on the board. My guess was that that was a power/standby LED which is now gone, and those pins are unused..
Two problems.
1) USB isn't working. Both Windows and my Unix boxes see a device, but don't recognize it I did double check the soldering on the thing, and touched everything up, but that was no help. Beyond that, I have no idea where to start debugging this. Maybe tear apart a usb cable and check connectivity to the something on the board?
2) The servo header output is wonky. In the PWM modes, I get a solid PWM signal between Out and Gnd. But Vcc looks like a bad version of that signal, with a sharp rise line and a slow decay. For that matter, now that I think about it, I checked it with other waveforms, and the waveform is clearly shorted to the VCC output of the servo connector. I'll check for shorts tomorrow, but it would be nice to have pointers to likely places to look to start with.
Thanks.
Checking the schematics, I added a jumper from what I think was pin 6 (the pin closest to the corner the switch is near) to pin 1 of U2, and another from pin 5 (adjacent to pin 6) to positive output of DB1. Pin 4 is shown as disconnected. Since the unit powers on and mostly works ok, I believe those are right.
But the other pins I have no idea what to do with. I can see that I should run one line from the other output of DB1 to pin 2. But it's shown as being wired to the two sides of a pair of LED (D10), and I don't see anything that looks like that on the board. My guess was that that was a power/standby LED which is now gone, and those pins are unused..
Two problems.
1) USB isn't working. Both Windows and my Unix boxes see a device, but don't recognize it I did double check the soldering on the thing, and touched everything up, but that was no help. Beyond that, I have no idea where to start debugging this. Maybe tear apart a usb cable and check connectivity to the something on the board?
2) The servo header output is wonky. In the PWM modes, I get a solid PWM signal between Out and Gnd. But Vcc looks like a bad version of that signal, with a sharp rise line and a slow decay. For that matter, now that I think about it, I checked it with other waveforms, and the waveform is clearly shorted to the VCC output of the servo connector. I'll check for shorts tomorrow, but it would be nice to have pointers to likely places to look to start with.
Thanks.