Hello,
I apologize if this is not the correct forum to post this kind of questions on. Please, let me know if there's a more suitable one.
To the topic - I've got a device built upon a MC9S08JM16 (a USB keyboard), which has a connectivity problem. When the keyboard is plugged into a computer USB port, it's not detected by an OS, and there's completely no USB interaction going on as can be seen by a USB analyzer program.
The microcontroller itself gets power and looks operational - I could dump its firmware and verfy it via USBDM. Also, it appears to be scanning the key matrix of the keyboard, as it should. The only problem is that the voltage on V usb33 is much less than 3.3v and there's almost no voltage on the USBDP (D+) and USBDN (D-) pins.
Is there any possibility this problem can be diagnosed and fixed?
If so, where do I start from and what should I check first?
