ParkingLotLust
Member
Heya guys. Ive been working on building a bunch of boards based around an 18F2455. **broken link removed** *NOTE - the 100nF cap on Vusb has been changed to 220nF (also tried 470nF).
I flashed about five of the boards (flashed the bootloader with a PICKit 2, and the software using the bootloader jumper), and came back in about half an hour, and all of a sudden none would be recognized with USB. I tried all the boards and none were recognized. I tried a few brand new chips and they werent recognized. After a lot of painful troubleshooting, I found that Vusb wasnt producing any power. And yes, VREGEN was set to ON in the bootloader code.
Ive solved the issue by setting VREGEN to OFF and supplying 3v3 to the Vusb pin, but I would like to know why the regulator has died on these chips. Any ideas?
I flashed about five of the boards (flashed the bootloader with a PICKit 2, and the software using the bootloader jumper), and came back in about half an hour, and all of a sudden none would be recognized with USB. I tried all the boards and none were recognized. I tried a few brand new chips and they werent recognized. After a lot of painful troubleshooting, I found that Vusb wasnt producing any power. And yes, VREGEN was set to ON in the bootloader code.
Ive solved the issue by setting VREGEN to OFF and supplying 3v3 to the Vusb pin, but I would like to know why the regulator has died on these chips. Any ideas?