What CPU socket is this? (laptop)

1607

Purchased a new motherboard for my ThinkPad T23 with an unknown BIOS password. Attempts to reset it - shorting the Amtel BIOS chip - did not work so a new motherboard was needed. Installed it but discovered the CPU socket does not match the old motherboard's CPU nor pictures of a T23 motherboard online.

I am hoping to get a full refund but I'd be grateful if anyone could tell me what CPU socket this is (on the motherboard with a "works" sticker on):

MS-DOS Manfred

It appears to be the "495-pin micro-PGA2" processor socket which was used by the Intel Mobile Pentium III as well as by the Intel Mobile Celeron.

1607

Thank you. Once I get refunded for the motherboard hopefully they'll let me keep it. I think it is a ThinkPad T20/21/21 motherboard whereas my laptop is a T23. Same layout except different cooler and socket.

*sighs* I might as well just grab another T23 for the cost of the parts I need...

WalkingContradiction

The zif socket says mPGA479m, so I'd assume it would work with gen2 P4 mobile chips. I've seen the same socket in an IBM think pad (model unknown), and it had some sort of P4 chip in it. At first I thought it was the same as the desktop socket that the gen2 P4 chips used, however the pin-pitch and overall Pinout is different.

Hopefully this helps,
TheWalkingContradiction

1607

WalkingContradiction wrote:

The zif socket says mPGA479m, so I'd assume it would work with gen2 P4 mobile chips. I've seen the same socket in an IBM think pad (model unknown), and it had some sort of P4 chip in it. At first I thought it was the same as the desktop socket that the gen2 P4 chips used, however the pin-pitch and overall Pinout is different.

Hopefully this helps,
TheWalkingContradiction

Thanks. As much as I'd love to hack a CPU onto this board I went ahead and paid the enormous sum of £7.20 to get another ThinkPad - this time a T20 - which is cheaper than getting a cooler and CPU for this board (coincidentally is also from a T20 so I guess I have a spare). If I come across a Pentium 4 mobile chip on eBay cheap I'll buy it and see what happens but the chipset seemingly only supports Celerons / Pentium 3 CPUs so I doubt it'd boot up. Worth a try I guess...

It's interesting how the ThinkPad T20 used a completely different socket to the ThinkPad T23 despite having almost identical CPUs (from the looks of things), identical board layout, and similar part numbers. They were both released at around the same time, too.

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As a side question, has anyone successfully removed a BIOS password from a T23 motherboard? In theory you can short two pins on the CMOS settings chip to bypass it on boot which is confirmed to work on the Z61m, T42, and even the T20, but the T23 has a much more complex 14-pin instead of 8-pin chip. Shorting the same two pins (by looking at a pinout on the datasheet) brings no results. The only other option is to solder a serial connection to the chip which could be a possibility but seems a lot of effort. However, it'd be good to get the laptop running again.