7921 Failure - Has MAC address D80000000401 ????

[asafayan]

We run WLCs with code version 4.2.130.0. Our 7921s run with code version CP7921G-1.3.2.

I have some 7921s that are failing. They hang at the Loading Network

Services stage of the boot-up process.

From the phone keypad, when I view the MAC address to attempt to troubleshoot the issue,the MAC address is listed as D80000000401. This is not a valid MAC address. The phone is not associated with an AP and therefore is not registered to Call Manager. I cannot find the phone by searching for that MAC

address in WCS.

[asafayan]

Opened a TAC case and got the following feedback:

CSCsm22589 Phone lost MAC address due to corruption in its (tiwlan_drv.o) file

Phone lost MAC or filled with bogus numbers.

[migilles]

That DDTS was unreproducible and believed this is not due to file corruption.

I would suggest to reboot the phone to see if it clears up. If not try to reload the 1.3(2) image and see if it clears it up.

If that still fails, would suggest to RMA that phone.

[asafayan]

Since the phone show some sign of physical damage on the antennae bump, I opened it up.

The antennae circuit board is attached the main circuit board with a relatively weak connector. By removing and reseating that connector the issue was resolved.

The phone reflected the actual MAC address. These phones are top heavy and often seem to drop right onto the antennae bump and I'll bet many of our RMAs could be resolved in this fashion.

We are considering replacing the 7921s with 7925s.

[migilles]

Not recommended to take the phone apart yourself.

To help protect the phone from frequent drops, I would suggest to look into the carry cases offered by zCover (www.zcover.com).

[asafayan]

hmmm...we own the phone and it's damaged. Exactly WHY can't I open it up?

We've had 7921s in production since they shipped out of the factory. We have approx. 1,000 in production and we experience a failure rate of approx. 2 percent.

Users hate Z covers. You cannot easily place a zcover in a docking station or a multi-port charger. We distribute them with every phone and very, very few users utilize them.

[migilles]

Just like any electronic device, if you open the case, you can potentially void the warranty.

Also there is risk you may damage something else in the process.

[asafayan]

Mike - the phone doesn't work and I'm not RMA'ing the thing. Any good engineer would want to know why it's not working.

So who gives 2 shits if I crack it open. The fact is - WHEN I RESEATED THE ANTENNAE CIRCUIT BOARD IT STARTED WORKING AGAIN!

We have a HIGH failure rate on these 7921 phones and they obviously CANNOT take a the 24/7 beating of a hospital environment. Otherwise we wouldn't be getting 20 of them returned every month that are non-functioning. And yes, many of them have been dropped...HELLO...they are essentially a cell phone. They get dropped.

[migilles]

If they are dropped repeatedly, then yes can cause damage to the phone. So if you expect many drops, then expect damage. If you want to help avoid that, then can go the carry case route. Or if you like you can look at the 7925G which is more tailored for your environment and a bit more rugged.