Cisco DPC3939 router

[frankiek3]

A recent lightning storm took out a Cisco DPC3939 router (and a LG 50PJ350 TV), on to the Cisco DPC3939:

Symptoms: Ethernet ports dead, one with faint green light. Wifi broadcasting but no longer connecting.

Found this Ethernet IC that was getting very hot: Marvell 88e6172
Found that it's VDD was shorted to ground (0.21Ohms)
Started removing 5 capacitors that were shorted to ground connected to VDD.
All capacitors were good.
First attempt at removal used my small rework station, but didn't budge. Then removed with the Honton. Middle of the chip has a grounding plate soldered to the board. Chip tested bad. Board with no chip tested no short. Hopefully the only bad component.

Now on to find a replacement chip. Not a very popular IC, the schematics I got for the router have the pin layout. Otherwise no datasheet for the IC. Two authorized dealers (only for quotes) and alibaba. I'm guess the chip will be about $10

[ben7]

Re: Cisco DPC3939 router

Good luck, my sense is that if a company doesn't give out datasheets without an NDA or something like that, then you aren't likely to be able to get those chips in small quantities. They only want to do business that brings in big $$$


Hm, there is a dev board for it, "DB1-88E6176-1", but it seems that you have to contact them to get a quote. It probably won't be cheap xD

-Ben

[frankiek3]

Re: Cisco DPC3939 router

I had another DPC3939 that I was going to sell, now using that. I got them for $80,$85

I'm 99% sure that the surge came from the ethernet connected to a shutdown mac mini (and out it's hdmi)

I should say, I assume that the VDD_CORE should not be measuring close to ground. The one port with the green led faintly lit makes me think it is shorted on.
I guess I'll sell it for parts. if I can't source the chip. Thanks.