T42p and bluetooth bootup issue - SOLVED

[Patrik28]

Hello everybody,

My Thinkpad T42p has suddenly started to have some bluetooth power-up issues. I have had bluetooth allways on, but now the bluetooth indicator-led stays off every time, when booting to Windows XP.

I haven't done anything abnormal lately, no driver updates, or new programs. The bluetooth has worked about two years without problems.

When I open the wireless application control panel (Fn+F5), bluetooth seems to be activated. But the BT indicator-led is off and all external bluetooth devices will stay unworkable. I can get the bluetooth working by changing it off and then again on (from Fn+F5 panel), sometimes the change must be done many times.
If the bluetooth won't wake up, Windows shows a message: "USB device not recognized."

My Thinkpad specific model is 2373-KTU with Windows XP Pro SP3.

All hints are welcome to solve this problem. It is a little disturbing to use a bluetooth mouse, when you have to switch bluetooth manually on after every bootup. Hopefully the bluetooth-card isn't about to break.

Regards, Patrik

[RealBlackStuff]

Your symptoms point to a failing Southbridge, which needs reflowing/reballing.
See the second link in my signature for UK/Europe

[killer]

Before trying anything else you might wish to try this:

Shut down.

Power on and press F1 to go to BIOS setup.

I think it is F9 for reset default values. (If not F9 it will tell you which option.)

Exit and restart.

Let us know if this works. It worked for me.

[Patrik28]

It feels odd, that the motherboard would need reflowing, because the notebook has been in the same place (on a desktop) all the time. Nobody hasn't even lifted it since it was removed from the original package.
But everything is possible with computers, i guess.

Thanks for the repairing offer, but 100-200 euros (incl. shippings) is quite much cash to spent to an old notebook. And it feels a little unsure, if the reflowing fails after 90 days warranty. Sorry for my suspects, but I quess I need to start looking a new notebook, if the bluetooth breaks up totally. All onboard usb- and pcmcia-slots are in use, so external BT-cards won't help.

I'll have to try killer's proposal too. Then I could buy an used BT-card, they aren't badly priced on ebay (10-20 euros).

[RealBlackStuff]

It's not the moving (or lack of moving) or flexing that is the only cause.
It's the On/Off cycles that cause heating up/cooling down of the laptop all the time.
Eventually the little solder balls between motherboard and Southbridge chip may come "unstuck" or "unsoldered".
Same can happen to ATI graphics chips (but not to integrated Intel graphics chips).

[Patrik28]

It seems that the killer's fix didn't work.

Yesterday I tried put the notebook to the factory default settings, (aka format the hdd), but it didn't vanish the problem. I noticed too, that when the machine warms up a little, it is easier to switch bluetooth on. And in every (warm-)reboot, it usually stays on.

By the way, the system shows "Windows has stopped this device... ...Code 43" error, if bluetooth is not recognized.

So, this problem may occur from failing joints. But how the bluetooth connections can work without a single problem, when the notebook is warm? If the joints are weak, I guess, it should affect to warm use as well, like cutting BT signal etc.

[Raceboy]

When warmed up, SB chip and PCB will be closer to each other pressing the cracks in the solder joints to minimum thus enabling the BT card to work.

[RealBlackStuff]

Like Raceboy said.
Slightly exaggerated: the heat expands and the cold shrinks those solderballs.
Over time the expansion/shrinkage increases, eventually causing intermittent and/or loose contacts.

[Patrik28]

Ok, this problem was luckily due to the bluetooth card.

I've changed it to a new one, and now BT works like before.

No need to reflow mobo (yet)

BTW. Is there some differences between 27R1880 and 91P7315 BT/modem-cards?
Do they belong to different Thinkpad models? I just noticed, that the replaced card was 91P7315, but it seems to work same way.