USB device not recognised (CY7C68014A woes)
Posted: Sun Mar 19, 2017 6:43 pm
I've been putting together a couple of boards but one of them is giving me jip.
One of them enumerates properly and the usb device shows up, the other does not.
There are no dry joints (that I could find, obviously). There are no shorts between any of the pins on anything anywhere, i've looked with a microscope and probed it with a meter.
I've replaced the CY7C68014A IC (actually I have CY7C68013A, but they're identical apart from power consumption it seems).
The only clue I have is that the oscillator doesn't seem to be running, I don't have a scope though so I can only see some voltages, but on the board that works the CLK testing point is at 1.6v (which makes sense I guess, if the meter is giving me an average) and in the one that doesn't it has 0v.
Pin 11 of the CY7C68014A has 3.3V (tested on the crystal's leg) but Pin 12 gets 0v.
If anybody has any insight it would be appreciated. I just can't find what's up with the bugger.
One of them enumerates properly and the usb device shows up, the other does not.
There are no dry joints (that I could find, obviously). There are no shorts between any of the pins on anything anywhere, i've looked with a microscope and probed it with a meter.
I've replaced the CY7C68014A IC (actually I have CY7C68013A, but they're identical apart from power consumption it seems).
The only clue I have is that the oscillator doesn't seem to be running, I don't have a scope though so I can only see some voltages, but on the board that works the CLK testing point is at 1.6v (which makes sense I guess, if the meter is giving me an average) and in the one that doesn't it has 0v.
Pin 11 of the CY7C68014A has 3.3V (tested on the crystal's leg) but Pin 12 gets 0v.
If anybody has any insight it would be appreciated. I just can't find what's up with the bugger.