Thinkpads Forum

Recently acquired a P9600 which was tested by the seller to upgrade a T400 with a P8400. The P9600 is known to be supported by the T400 platform.

After installing it and trying to power on the machine the LED panel lights cycle on and then off with a slight tick sound coming from the speaker within one second. Otherwise there is no response, no beeping, no fan spin.

If I reinstall the P8400 everything is fine. I am wondering if this is an outdated CPU microcode BIOS issue (currently 1.18) or there is something defective with the P9600? I want to believe the former but shouldn't it at least spin the fan if that was the case? I don't have a spare battery at the moment so can't safely upgrade the BIOS. Any help is appreciated.

If you enter your T400 model number into Lenovos quick path here you can look at the 'read me' file for the latest BIOS upgrade. You might want to read it and see what fixes and upgrades have been applied for the T400.

What BIOS version is your T400 flashed with?

1.18 and the newest is 3.20
There have been several microcode updates but I don't have a battery available to try.
Currently reading up on how to do it without one.

Just an update. Updated the BIOS manually without a battery without hitch. Only problem is the P9600 still does the same thing. Think the chip might be defective? Pretty sure the P9600 is compatible?

I do not advise doing the update without some sort of uninterrupted power supply. With that said- Good luck on your update! If it is a success post back because I will be wondering about it. Cheers