R40 : Upgrade from P4M to PM??

[clickpoint]

I've enjoyed my r40, so decided to get another one.
Bought a "AS IS" off ebay ... Interesting, machine.... R40 body with 15 inch screen! Someone must have changed screens

Product: ThinkPad R40 2681-C8U [change]

Operating system: All [change]

Original description: P4-M 1.9GHz, 128MB RAM, 20GB 4200rpm HDD, 14.1 XGA(1024x768) TFT LCD, 16MB ATI Radeon M6, 24x-10x CD-ROM, Wireless upgradeable(MPCI), Modem(CDC), 10/100 Ethernet(LOM), UltraNav, IEEE 1394, 8 cell Li-Ion battery, WinXP Pro


Added memory, plugged it in, NOTHING!!!! Lights flashed and then died. Took keyboard off, and noticed that fan was not plugged in, and that the screws were loose----- NO CPU

From above, the machine came w/ P4M processor... I have a 1.7GHz PM processor that I was going to upgrade my other R40 to.... could I use that processor in this machine??

Also, per manual "When replacing the CPU, you must replace the thermal pad FRU 5022BZ4023A also" ---- What is the thermal pad? Is that what IBM uses instead of thermal paste (eg artic silver)?

Thanks for the help

[pianowizard]

From above, the machine came w/ P4M processor... I have a 1.7GHz PM processor that I was going to upgrade my other R40 to.... could I use that processor in this machine??

Nope.

[clickpoint]

From above, the machine came w/ P4M processor... I have a 1.7GHz PM processor that I was going to upgrade my other R40 to.... could I use that processor in this machine??

Nope.

what would be the slowest and fastest processor that I could use in the laptop?

[underclocker]

Bought a "AS IS" off ebay ... Interesting, machine.... R40 body with 15 inch screen! Someone must have changed screens

Actually, upon occasion the info on the IBM website is incorrect. Unless the cover is much larger than the base, meaning the latches don't work properly, then there wasn't a switch, just an IBM typo.

R40's went up to 2.4GHz, but a 2.6GHz might work, like on A31's.

Good luck.

[wolfman]

Also, per manual "When replacing the CPU, you must replace the thermal pad FRU 5022BZ4023A also" ---- What is the thermal pad? Is that what IBM uses instead of thermal paste (eg artic silver)?

Basically yes, it's a termal interface material between the CPU and the heatsink/fan. As long as the base of the heatsink makes good contact with the CPU you could use pretty much any of the available thermal compounds / pads (IMHO).

[clickpoint]

Bought a "AS IS" off ebay ... Interesting, machine.... R40 body with 15 inch screen! Someone must have changed screens

Actually, upon occasion the info on the IBM website is incorrect. Unless the cover is much larger than the base, meaning the latches don't work properly, then there wasn't a switch, just an IBM typo.

R40's went up to 2.4GHz, but a 2.6GHz might work, like on A31's.

Good luck.

Yes the cover is much larger than the base!

[hoplite]

You should post some pics!

[AHuan]

I tried upgrading a processor in an r40 once... it's not hard. Use a drop of thermal paste (the "arctic ice" website has good instructions) instead of the thermal pad - thermal pads are basically for manufacturing convenience. I found out half way through the upgrade that the p4 I pulled out of another laptop was actually a desktop processor and the heatsink didn't fit.... but I reassembled it and it all worked....
BTW, this was an r40 with a celeron m 2 Ghz. I recommend you find out what chipset your motherboard uses, then go to the intel site and look up the chipset. That will tell you what processors are probably supported - and besides, I noticed PMs are actually only about 30 bucks on ebay so it might be worth a shot if the chipset supports it. Make sure you get the type without a heatspeader - the heatsink will not fit otherwise, though you can actually remove the heatspreader yourself, I think it might be difficult.

Who said a PM couldn't be used? Are you sure?

[pianowizard]

I recommend you find out what chipset your motherboard uses

There are R40's with P4-M and those with P-M, which use Intel chipsets 845MP and 855PM respectively.

[clickpoint]

I recommend you find out what chipset your motherboard uses

There are R40's with P4-M and those with P-M, which use Intel chipsets 845MP and 855PM respectively.

How do I find out what "chip set" is used on the motherboard?

[wolfman]

The easiest way to do this (may be others just as easy) is to use CPU-Z (google for it, it's freeware). It's a very small application that will give you a descent amount of processor, ram and motherboard detail including your motherboard chipset.

[Temetka]

How can he do that? His system is non-functional until he adds a CPU, thus bringing us back to where he is trying to figure out which one he can use.

My guess would be to pull the HSF and check around that area for the northbridge chip and check the markings on it.

[Terrahawk]

One way you can use to tell if your CPU will work in your R40 is to simply try to put it in. A Socket 478 Pentium-M (Banias or Dothan) will simply not fit into a Socket 478 socket designed for a Pentium 4-M. The key pins in the corner are a different pattern.

Also, a R40 with a Pentium 4-M or Celeron simply cannot use a Pentium-M or Celeron-M of any variant, and vice-versa. The reason is detailed quite simply in the datasheets for CPUs (which can be downloaded from Intel) - the pinouts are completely different.

[clickpoint]

OK>> ordered P4-M 2.0GHz from ebay $24 ; put in memory and ......... nothing on screen

Though works w/ VGA output ; booted up LINUX w/o any problems....

Now the screen --- 15" screen ; can barely make out SPLASH on boot up ; inverter vs cable vs backlight ?? Where to start first?

[jamiphar]

....Now the screen --- 15" screen ; can barely make out SPLASH on boot up ; inverter vs cable vs backlight ?? Where to start first?

You can make out the screen, but it's very very dim?

If so, this narrows it down to a few possibilities: 1) You may have a loose/broken cable to the inverter. 2) Could have a bad inverter. 3) The backlight's burned out.

I would suggest checking the inverter cables first, since it won't cost you anything. If the connections are good and you still have the same issue, then I would swap out the inverter. If this still doesn't solve it, then you need to get a new CCFL backlight and replace the old one.

One more thing to try before spending money; try pressing the the lid closure switch repeatedly (a pen or a paperclip may help) and see if there's any difference on the screen. I've heard of dirty switches getting stuck, thus keeping the backlight from turning on when the lid is opened.

[clickpoint]

....Now the screen --- 15" screen ; can barely make out SPLASH on boot up ; inverter vs cable vs backlight ?? Where to start first?

You can make out the screen, but it's very very dim?

If so, this narrows it down to a few possibilities: 1) You may have a loose/broken cable to the inverter. 2) Could have a bad inverter. 3) The backlight's burned out.

I would suggest checking the inverter cables first, since it won't cost you anything. If the connections are good and you still have the same issue, then I would swap out the inverter. If this still doesn't solve it, then you need to get a new CCFL backlight and replace the old one.

One more thing to try before spending money; try pressing the the lid closure switch repeatedly (a pen or a paperclip may help) and see if there's any difference on the screen. I've heard of dirty switches getting stuck, thus keeping the backlight from turning on when the lid is opened.

Repeatedly pressing switch didn't help.....waiting for new inverter

[clickpoint]

Well.. it's been a while...

I got a new inverter and it DID NOT WORK... not what I hoped for...
so now I need a new LCD (me thinks) or backlight >>> got another 15" (told XGA, but actually SXGA+) -- but now I don't have the right cable. UGH!

Ordered cable (but not sure if SXGA+ would work on my machine w/ 16mb).... plugged it in, and NOTHING!!!!!!

What is going on???? "LIGHTNING BOLT HITS" ---- why don't you try the LCD on the other R40?

IT WORKS!!!!!!! (Why didn't I do this earlier)????

SO why doesn't it work on the other R40??? I decide to take it apart to see if anything is loose, etc....

Take it all part, don't see anything obvious...

Let's try the LCD again with covers off .... IT WORKS now!!!!!

Culprit ----- Lid closure switch was bent, and kept the switch pressed. Bent it upwards a little, put everything back together again, hit the power button --- SPLASH SCREEN!!!!

If only I had done this before.... would have saved quite a bit of $$$$..... but would have missed out on the learning experience.

Popped in HD, ran recovery CDs, no-1802.com + intel 2915 from old dell laptop and now I'm surfing away on my 15" screen on 14" base!!!!