01-27-2012 11:15 PM
Has anyone tried installation of a sierra wireless MC7750 card on a X220 tablet? I've gotten hold of a MC7750 and intend to install it on my X220 tablet and try it with Verizon 4G network.
01-28-2012 07:13 PM - edited 01-31-2012 01:16 PM
I have not tried it, but I can tell you that most likely it will not work in the default configuration. Lenovo machines have a whitelist that checks to see if the WWAN card inserted into the machine is regonized and certified. If the machine doesn't recognize the card it will display an 1804 error. Since Lenovo doesn't yet sell these cards yet, it's unlikely that this card is on their whitelist.
Some people modify their BIOSes to recognize cards that Lenovo hasn't put on their list yet. I believe you can find such moded BIOSes here:
or alternatively maybe in the forums in http://www.mydigitallife.info/
There may be newer versions of the BIOS in the same forum, but I haven't checked in a while.
I've been waiting for months for Lenovo to support the MC7750, or another LTE card like it. I've been told by several sales people that "it's right around the corner". Pretty much hogwash so far. I haven't gone the step of ordering one of these card yet hoping that Lenovo will officially support it soon. Please post back though if you do end up moding your bios. I'm curious to know how well it works. Also read up on taping pin 20. Some people say it's necessary in addition to moding the bios.
01-28-2012 07:40 PM
Oh yes, one other thing:
You'll find upon opening your system that there are 3 antenna attachment points on the MC7750, but only 2 antennas dedicated for the WWAN card on the x220. You may have another separate antenna if you ordered the system without a camera and the extra WiFi antenna. I called Sierra Wireless to discuss this at one point and was told that the two outer antennas are for WWAN, and the central antenna is for GPS signal. I'm not 100% sure that I'm remembering that order correctly, but I am certain that my contact told me that one of them was dedicated to GPS. Assuming that you have the standard system with only 2 antennas, you'll have to choose if you want a better WWAN signal or getting a GPS. The WWAN should work fine with only one connected, but will be much less likely to have dropped packets if you have two attached for WWAN because it should combat a problem called frequency selective fading much better.
One other wrinkle: I'm not 100% sure if the WiFi antenna, or one of the WWAN antennas will work with the GPS. GPS signals are in the 1500 MHz range which is in between the 800-1900 MHz range that the WWAN card is designed to work in, but who know if the GPS component was designed to accept only a specific length antenna, or if it can work with a range of possible lengths.
You may want to experiment with attaching/detaching the antenna a bit. It is possible if you keep your keyboard slightly detached to get access to the WWAN card while the system is running.
Another possibility is to buy a separate antenna. That's a LOT of hassle though and requires disassembling the LCD. There are also antennas that supposedly can be placed in the main body of the laptop, but I suspect that they don't get very good reception given the noisy environment of the laptop.
01-30-2012 01:30 PM
Thanks for your tips. I'll try them out this weekend and will post back on how it went. I did install the MC7750 on my X220T - mine has only 2 antennas, so have not connected GPS, I connected the main and aux. I'll first try to get the card working and then try something for GPS.
01-31-2012 10:34 AM - edited 01-31-2012 01:17 PM
Did your x220T start giving you 1804 errors on boot after you installed the MC7750? If you installed the card then I'm surprised you can still boot without using one of the BIOSes mentioned above.
01-31-2012 12:39 PM - edited 01-31-2012 12:41 PM
Interesting. When you say that it isn't in the devices list, do you mean in "Device Manager". It would be under "Modem", "Network adapters" or "Other devices" I believe.
01-31-2012 04:28 PM
Yes, I had meant the Device Manager in control panel, the MC7750 does not appear under Network Adapters, Modems or Other Devices.Also it doesn't show up when I do a fn+f5. Also Mobile Broadband shows as disabled on Lenovo Access Connections. I think the BIOS has not reported the MC7750 as new hardware to the OS. Before I try the modded BIOS you had suggested, I'll also try installing the MC7750 on my HP and DELL latops to see if they recognize them. I can't wait for the weekend to try these options out :-) Simply can't find the time to try these during the week.
01-31-2012 04:42 PM
Yes, I agree that trying it out first on your HP would be wise. The fact that you are not receiving an error on boot makes me wonder if there is something wrong in the connection between the laptop and the card, and/or on the card itself. I did a quick search to find out if the x220 laptops had a different behavior from previous generations of machines and silently disabled the WWAN cards instead of halting on boot. The links I found though implied that people with x220's who had inserted other WWAN cards experienced halts.
Out of curiosity, where did you purchase this WWAN card? I may want to buy one myself if you are successful.
By the way, here is a more recent BIOS that I ran accross: