[SOLVED]820-4924-A USB issue

[gadgetfix]

one of the USB ports not working. One of the diodes have fallen off. im trying to salvage one from a donor board but the closest thing i have 820-3462? Can anyone tell me if I could use one of those diodes?

thanks in advance

 

[jadao]

They seem close enough (5.3V-0.22pF), but are you sure this what's preventing usb from not working?
They act like transient voltage suppressor/esd and rf interference stuff...look for further damage, do you get 5v on L4605 pin 2 and check continuity on L4600 filter.

 

[dukefawks]

It should work without the diodes. Just for testing though, they should be installed again for ESD protection.

 

[gadgetfix]

Yes i should of mentioned. The usb werent working regardless - however I scratched one of these off by accident when poking around and also wanted to replace as pre-caution.

 

[gadgetfix]

hey guys. 5v present on L4605. continuity present on L4600 filter but port still dont work?

 

[dukefawks]

Diode mode on pin 5,6 of J4600? Check U4650 area, check voltage on pin 10. Did you check if J4600 is damaged?

 

[gadgetfix]

i was suspecting u4650 it looks good. j4600 looks good

j4600 pin 5,6 is .500 .505

on r4650 there is 3.42 - having said that i removed the u4650 and the only pin corroded is pin 10!!

LESSON learnt: dont be lazy - never underestimate under chips!

thanks duke!