How to measure a 100/1000BASE-T transformer module ?

[Gabriel]

I have a router that all the lan ports + the wan port is dead.

How can I test the transformer modules to see if they are working or not ?
I have the Delta Lf9402 modules.


Thanks

[japlytic]

Re: How to measure a 100/1000BASE-T transformer module ?

Did the WAN port get connected to a phone line? Some people think the "internet" port is for the phone line, and many are not marked to warn people not to connect it to a phone line.
Ethernet transformers can be a bit hard to test, considering that the windings show as shorted at DC or low frequencies. I found that fact useful in tracking down a defective network port in our new house, and the cause was a wire (used for Gigabit) missing its target on the wallplate connector.

[Gabriel]

Re: How to measure a 100/1000BASE-T transformer module ?

I found this router in the garbage at work so I do not know what happend to it but it has had a hard life - https://www.badcaps.net/forum/showth...3177#post93177

I replaced the two blown caps but the lan and wan port was still dead.
I was up all night and removed and measured all the electrolytic caps but they were all fine. I did notice the ip101a ethernet transceiver was really hot, I will get one on ebay and see if replacing it helps.