820-2936 - Ethernet never gets link.

[gcain]

Customer is a field technician, so no getting around not having Ethernet. /groan

The network card is detected and can be seen everywhere you would expect but it never seems to sense when a cable is plugged in.

I checked for continuity between 1,2; 3,6; 4,5. No pins are shorted to ground.

Any suggestions?

 

[dukefawks]

Bad connector? Plug in cable and check the pins on the other side like you did at the connector. 1-2, 3-6, 4-5, 7-8.

 

[gcain]

Continuity at the end of a Cat 6 is all good. :/

 

[dukefawks]

Didn't see you checked pins 7-8 in your first post. If that is all OK it may be a bad LAN chip.

 

[gcain]

I did check 7&8, just forgot to type them.

LAN Chip being U3900?


He is a field tech, always plugging his lan into various devices; maybe D4000/1 (ESD protection) are faulty. This is similar to what I find on USB in fact.
I'll measure / swap them quick and report back.

 

[gcain]

So D4000/1 is NOSTUFF.

Turns out R4000 was burnt out. I swapped it but still getting no link.

 

[dukefawks]

Chip is dead. Maybe transformers too.