SOLVED FV-1 short circuit

[xsaardo]

I wasn't getting any signal out of the FV-1 path on the dev board so I tested all the voltages and it seems like my 3.3V is shorted with ground with a 20 ohm resistance between them. Anyone have any tips on how to find the problem? I've already desoldered the 3 control pots/voltage regulator/EEPROM/C18 from the board since they all have physically close connections between the digital 3.3V node and ground. Not sure how to determine if my specific PCB or FV-1 chip are problematic. Thanks!

 

[p_wats]

Have you checked all your solder joints for bridges? Is your regulator socketed (so you could try another)? Did you solder the FV-1 yourself?

 

[xsaardo]

Just double checked all the solder joints but I've actually completely removed the regulator and the EEPROM sockets from the board. The FV-1 came presoldered on the board

 

[p_wats]

So there's still continuity between 3.3v and ground without those elements?

 

[xsaardo]

Yeah... my guess is a short between pins on the FV-1 or the traces? I've looked all over the chip though and can't seem to find the cause of the problem.

 

[p_wats]

In the past I've had sold bits resulting from desoldering stuff, etc. sneak their way between things. Do you have a magnifying glass or anything? Have you traced continuity with your DMM?

 

[xsaardo]

So.... as a last attempt I decided to desolder the FV-1 and USB interface chips - Turns out the USB interface is somehow causing this short... Thanks for your help though!

 

[p_wats]

Nice. Glad you got it sorted!