T420 - replace modem with firewire port?

[kitor]

I'm thinking about replacing my x220 with t420. Found that some models had FireWire 400 port instead of modem - and as I use firewire frequently (ec adapter) and modem is useless, that would be a nice-to-have feature.
BUT it's hard to find one with firewire, at least in my country. The question is - do they have different motherboards, or it's just a matter of replacing this small board with USB & firewire connectors?

[brchan]

The modem and usb port on the back are actually connected to a small daughter board, which plugs into the mainboard. You need to get the firewire + usb version one and the cover (FRU 04W1604) and it should be plug and play. I am not sure what country you are in, but the small boards seem to be > $13 USD.

[kitor]

Thanks for reply,
Cover doesn't really matter, as I probably mod it to use big (6 pin) connector... it's much more durable. I'm more interested about this daughter board, is there any part id for it?

[brchan]

Couldn't seem to find an fru, but the part number seems to be 0A65198, judging by this result in ebay: http://www.ebay.com/itm/Lenovo-ThinkPad ... Sw7FRWZPWO

Note: I am in no way affiliated with the seller.

[rkawakami]

HMM reports that the I/O sub card for the T420 with USB and 1394 (FireWire) ports is FRU 04W1631. There are still a couple on eBay at the moment (albeit at a much higher price than what brchan referenced).