T61p - few questions

[j-dawg]

Just bought a T61p; got some ?s about the machine.

1. Was the "two DIMMs" issue ever worked out? I want to know if I can use both DIMM slots or if I should buy a single 4GB DIMM, but I don't know if Lenovo ever fixed the problems with random crashes and shutdowns with both RAM slots filled. (it came with one 2GB stick in it, which passes memtest86+)

2. How important is the battery for heavy usage? I've been experiencing random shutdowns (20-40min) running on AC with no battery installed (battery is not functional). This only happens when I'm playing a video game (CS:Source). If I replace the battery, could I expect this to disappear? I noticed it when I was using the 65W power adapter, and I think it's become less frequent since I switched to the 90W, but I don't know for sure. Basically what I'm asking is, does anyone know if the computer draws from the battery under heavy load?

I did replace that one 2GB stick with a different 2GB stick and a 1GB stick and the problem didn't reappear over about an hour of play; that's not exactly bulletproof, but it might just be a RAM issue.


This thing is in good condition besides the battery and this shutdown thing. Ordinarily I'd not hesitate to ship it right back to the seller, but this is the holy grail of T61p's - it was made in August 08, after the whole inevitable-failure nVidia GPUs were no longer being installed. It's got the T9300 and the FX570M and it's huge as heck, and I really like it, so any help I can get to not send it back is greatly appreciated.

[rumbero]

1. Was the "two DIMMs" issue ever worked out? I want to know if I can use both DIMM slots or if I should buy a single 4GB DIMM, but I don't know if Lenovo ever fixed the problems with random crashes and shutdowns with both RAM slots filled.

Never heard about any such issue related to any T61(p). Where did you hear/read of any such issue? Do you have any information source on the web which you could share with us?
I have several T61's running each with either 3, 4 or 8GB RAM, always with both banks used, and never ever ran in any problems.

Besides faulty RAM modules, random shudowns might also be caused by faulty batteries. According to your statements your machine came with a bad battery, so better try to replace it with a known good one.

2. How important is the battery for heavy usage? [...] Basically what I'm asking is, does anyone know if the computer draws from the battery under heavy load?

Yes, during high peaks the machine additionally draws some power from the battery. If no battery is present, it also typically tends to throttle the CPU. In your usage scenario you better shouldn't run your machine without any battery.

[...] but this is the holy grail of T61p's - it was made in August 08, after the whole inevitable-failure nVidia GPUs were no longer being installed.

Care to share the exact product-id/type printed on the the sticker at the machine's bottom? Please ignore the one ending in CTO, it needs to be exact. If the sticker doesn't show anything worthwhile, you can also find this in the first BIOS screen, being embedded as the first seven characters/numbers of the "System-unit serial number". Thanks!

[j-dawg]

http://forum.lenovo.com/t5/T61-and-prio ... 63/page/77

Of course, that is a very lengthy thread which eventually devolved into complaining about everything wrong with the T61p, the black sheep of the Thinkpad line..but there are some relevant posts in it. Besides these shutdowns this is a great machine and I hope I can keep it. I believe this is only the p models, not the regular T61's, and I don't know if it's all of them or if it ever stopped.

Happy to hear that about the battery. I guess I'll stay away from heavy usage until the new one arrives. eBay seller very helpfully sent me a new one right away, without needing me to first send in the old.

Type number is 6457-Y74, I believe. There were 20 for sale so I think it was some sort of institutional selloff. Also, there was a "diversity education" DVD in the drive from the FDIC, which I doubt anyone watches for fun, so I'm guessing this is a post-government machine...nice.

[rumbero]

http://forum.lenovo.com/t5/T61-and-prio ... 63/page/77

[...] and I don't know if it's all of them or if it ever stopped.

As an educated guess in these matters, i'd rather assume that these will be just first typical symptoms of a dying nVIDIA GPU, with the amount of DIMM's being a misleading false cause of the machine behavior.

I am intensively reading up on anything T6x related on various international Thinkpad boards, including the one from the link you cited, the lenovo-ibm forum on notebookreview.com, as i am a native German speaker also the German thinkpad-forum.de, and last not least this fine forum here. But i have never ever read anything about any such fault in any T61's before, so i must assume that this is just a singular issue.

Type number is 6457-Y74, I believe.

Thanks for this detail, contributing yet another safe T61 to the far too short list of non-nVIDIA-bugged T61's!

Here are the manfacturer specs for this machine:

6457-Y74: Based on 6457-CTO: T9300(2.5GHz), 2GB RAM, 100GB 7200rpm HD, 15.4in 1680x1050 LCD, 256MB nVIDIA Quadro FX 570M, CDRW/DVDRW, Intel 802.11abg, Bluetooth, Modem, 1Gb Ethernet, UltraNav, Secure chip, 9c Li-Ion, WinVista Business 32

And here for another one which is based on the former:

6457-RE2: Refurb from 6457-Y74: T9300(2.5GHz), 2GB RAM, 100GB 7200rpm HD, 15.4in 1680x1050 LCD, 256MB nVIDIA Quadro FX 570M, CDRW/DVDRW, Intel 802.11abg wireless, Bluetooth, Modem, 1Gb Ethernet, UltraNav, Secure chip, 9c Li-Ion, WinVista Business 32

So, for the eBay searching crowd, the 6457-Y74 and the 6457-RE2 should most likely be a safe buy regarding nVIDIA graphics.

[j-dawg]

Well, I've discovered (via Speedfan) that the GPU is running quite hot - it idles at ~67C and will quickly ramp up to 80-90C upon opening a video game, increasing further as the game is played until it shuts down due to overheat at around 100.

This sucks and I have tried to solve the problem by replacing the thermal grease on the CPU and GPU. I also reset the BIOS, to see if any strange settings had been changed. The CPU actually idles quite cool, at around 38-40C, but the GPU temps have not changed, according to both the temperature monitor and my finger on the heatsink. I suspect that the cooling hardware is not the issue either, as the heatsink gets very hot at the GPU. It seems to function just fine aside from the high temperatures and the shutdown' I get no artifacts or strange behavior from it.

Is there any reason the GPU would just run hot? I really can't think of any - it is not one of the defective batch of G84/86 chips, it's not especially stressed, and the cooling hardware seems to be in good order. When I have more time tomorrow I will check that I applied enough thermal paste, but I don't think that was the problem.

[j-dawg]

I couldn't wait until tomorrow - I tore the heatsink out and saw that, based on the grease on the bottom of the heatsink, the GPU was not making full contact - about a third of the square machined into the heatsink, representing the borders of the GPU die, was untouched by grease.

Looking at the heatsink itself, the plate that covers the GPU and northbridge is not flat; there is a subtle enough bend that I can't tell if it's intentional. Is this correct? I'm trying to find high-res photos of the heatsink online, but I can't get any good ones. Has anyone got good photos of the 15" T61p heatsink?