Analog Discovery 2 possibly damaged, any ideas for how to debug?

[Chuankun]

Hi,

 I've been keeping my analog discovery 2 connected to my PC for forever, with also an external power supply (official one from Digilent) and things have been fine. I haven't used it recently, but just noticed today that it seems to be dead. There is an on-board LED which used to light up, but now is not doing anything. It doesn't get recognized by the computer (nothing in device manager). 

 I don't see anything obviously burnt. Any suggestions on how I can figure out why it died, and if I can possibly repair it? 

 Thank you!

[attila]

Hi @Chuankun

See the following posts:

 

[Chuankun]

Hi @attila,

 

 Thanks for pointing out the relevant posts! I'm following this step by step now and would greatly appreciate your further guidance. 

 I checked the ferrites, they seem fine (FB18, FB19 both close to 0 Ohms when unplugged, Vbus at 5V, GND is at 0V). 

I then checked the voltages. VPLL, VCCD, VPHY are all at 5V instead of 3.3V, so that's probably part of the problem. VCCORE and VCCA are at 1.8V. 

 

Now, what are the next steps that I can do? I didn't quite understand the USB power control diagram below. Specifically, I didn't manage to locate IC21 (ADM1177) on the PCB board. 

 

 Thanks again for your help!

[attila]

Hi @Chuankun

The USB controller could be damaged by high USB voltage. Make sure to look for a faulty/unregulated USB hub supply to prevent further problems.
You could try replacing the FT232H but likely other ICs on the board are damaged as well.

The ADM1177 is probably fine, this is rated up to 30V

 

[Chuankun]

Hi @attila,

 

 Thank you for your suggestion and I managed to solder a new FTDI chip on. Now the device is giving me some response, see the error message below. Do you have any suggestion on if this can potentially be fixed? 

 

 

 I'm also not sure if I soldered the FTDI chip all correctly - it's hard for me to hand solder that... 

Thanks again!

[attila]

Hi @Chuankun

The FPGA IDs are not read correctly over JTAG.
The USB controller soldering may not be good or other ICs are damaged as well, like the buffers or the FPGA.

 

[Chuankun]

Hi @attila,

 

 Thanks a lot for your help! Unfortunately I still couldn't get it back running. Gave up and got new one?