So my friend just got the Lenovo U350. It is the new line from Lenovo that uses the ulv processor and weighs only 3.5lbs. He came to me because the fan on his machine was constantly on and one side of the laptop would get super hot. The battery life was also around 4 hours as opposed to the 5 hours advertised. Since it was using a low voltage cpu, this seemed odd to me. I decided to open her up. As I was opening screw after screw, I kept coming across these little oval "lenovo" stickers which I imagine were put in place for warranty issues. I gently peeled them off and put them aside so that I can return them when I was done. My plan was to get to the heat sink and remove whatever heat pad they had put on it and replace it with some silver grease.


After countless screws and parts, I got to the heat sink, a single skinny heat pipe that ran across the the gpu and cpu to the fan. To my amazement, when I pulled off the heat sink, I found another "lenovo" warranty sticker. IT WAS ON THE CPU IN BETWEEN IT AND THE HEAT SINK! What the hell! Attached are some poor quality images I took with my cellphone of it. I was not ready with a good camera, so I apologize for how crappy the images are.

Well, I scrapped off the sticker with a razor. Removed the heat pads from both the cpu and gpu. Put the grease on and put everything back together. After powering it on, the fan did not kick in until vista was fully loaded. After adjusting the start up programs and turning off aero, the laptop is now constantly cool. The fan rarely turns on AND the battery last 7-8 hours on idle with the wireless on! I just watched the planet earth blu-ray set using an external player on it. No stuttering.

Just wanted to share my experience. This is a great laptop if lenovo didn't go out of their way to cripple it. I hope I didn't void the warranty


Pictures of U350:
http://i27.tinypic.com/33kpugn.jpg
http://i30.tinypic.com/vo0gtt.jpg
http://i30.tinypic.com/rk8px5.jpg
http://i32.tinypic.com/155mnhh.jpg
http://i25.tinypic.com/11i25x2.jpg

Hi, thanks for the information!! I really like everything about the U350 except for excessive fan noise and heat (on left palm rest and vent).

Can you confirm, now that you've had it running for a while after your mod:

1. that fan noise is no longer issue (except under heavy load), and

2. there is no (or significantly less) heat on left palm rest

These are the 2 reasons why I'm thinking of returning the U350. But if there is a fix that would be great, although I think Lenovo should issue recall, and/or accept responsibility to fix this issue under warranty.

I'm glad to help.

1. After some more time with the laptop, I can say that the fan still turns on most of the time but is on its lowest speed. So it is not as loud. You can hear a definite increase in sound once you start playing videos and the like. But unlike before, the fan will occasionally turn off all together.

2. Using my cooking thermometer, I can say the area left of the touchpad and near the keyboard is around 93F while the right side of the touchpad is 75F. On the under side of the laptop directly underneath the 93F reading, it is around 104F. It feels slightly warm to the touch but not "hot". I don't have an unmodded U350 to compare. These temperatures are at idle in an air conditioned (75F) room.


I should have added a warning that this is not a mod for everybody. You can easily kill your laptop. You pretty much have to remove every screw in your laptop and detach every cable. There are multiple different length and diameter screws. You then take the most sensitive part on your laptop, the cpu, and scrape it clean with a razor, rinse it with alcohol, and then put highly electrically conductive grease on top of it. A single slip and you are done.

I agree that it would be best to fix this under the warranty, but good luck convincing them that something is wrong. I don't even understand how this can be common to all the u350's but removing the sticker and adding the silver sure did fix a lot of issues for me.

(Also about the open PCI-express slot, it did not recognize my spare wireless card under Vista when I installed it in there. It acted as if nothing was installed.)

Thanks for the information. Very helpful!

Too bad about this quality issue.

I've also noticed screen contrast is not as good as the Lenovo S12. Long-term viewing fatigues my eyes faster.

It looks like the U350 is not a keeper. I like just about everything else about it though.

Might look at Acer Timeline 3810Tz or wait until S12 comes out with Ion. S12 runs cool. Plus has full sized right shift and better screen contrast.

Lenovo, you were so close!!

Moved to Lenovo Section.

cheers ...

Freddyspam - thanks for your reporting on this. I just ordered a U350 yesterday and I will be keeping a close eye on the heat. It is great to know there is a solution, if it gets bad enough to warrant a fix and Lenovo won't make it right.

When you had the U350 apart, did you notice if the SU2700 CPU is soldered to the MB or pushed in? I'm thinking about future CPU upgrade possibilities. It would be nice to know if a Core2Duo could be dropped in at a later time ...

Mike

It is soldered on. I think all of the ULV's are BGA. To be honest, it is not impossible to upgrade, just difficult and costly.

This guy did it on a Sony UX: http://www.micropctalk.com/forums/sh...5354#post35355

Hi,
I have an U450p and there are also some problems regarding temperature and battery time, so I was wondering whether the problem is present in the U450p series also. Could you say how you determined the CPU temperature and what values you would consider "hot" or "cold"? I used CoreTemp and the CPU temperature is between 35°C in idle mode and 55°C under full load.
I tried to open the U450p and removed all screws I could find. I could lift the lid a bit, but there was on screw or hook I could not find, must be below the s,d or f of the keyboard or the RAM slot respectively. Any hints?

Those temps are great, are you in a walk in cooler? I do not trust them if room temp is 70F/21C.

I would consider these temperatures very low, too, but Lenovo thinks it's necessary to blow the fan (at medium speed for T>35°C and at full speed for T>40°C). Those are the values as reported by CoreTemp. I also tried Hardware Monitor by CPUID and it reports values 5°C lower. Speedfan also reports 5°C less.
Under Linux I tried lm-sensors and the values are a bit higher, but maybe that is true also.

I guess the temperatures indeed are low already, and my problem can be fixed only with more sensible fan settings in the BIOS, something I cannot do myself. Right now, there is no hysteresis and the fan is turning on/off all the time, quite annoying. Battery lifetime is about 4.5 hours, instead of the promoted 6 hours.

Have you tried using TPspeedfan to set the fan speed and temps? The goal is to lower the fan noise. You'll probably end up losing battery life because of the extra load on the CPU at idle caused by the program running and the extended fan time needed at the lower fan speeds you'll be using.

There are lots of things you can do to reduce the heat produced by your laptop when it is at idle:
1. Turn off Aero or at least just the glass feature
2. Turn off the sidebar
3. Turn off all unnecessary programs at startup

Undervolting might be possible, but it was not on the SU3500 I had.

As far as dismantling the laptop, it should be somewhat obvious what you need to remove (every screw in sight). I remember having a problem with the keyboard myself. Of course, I had a different laptop, but make sure to remove the harddrive, ram, wireless card, and anything else removable. They might be hiding screws. In the end, you might have to use a little muscle to pop out anything caught on a tab.

Someone sent me a private message a little while back asking for help dismantling. He had actually broken a part off the motherboard. So be very careful.

I doubt you'll accomplish much by doing this. The best you'll do is replacing the heat pads with thermal grease. No one else has reported the sticker issue I had and your temps seem very reasonable. You may get more battery life with a more efficient cooling system, but it may not effect the fan noise.

Good luck!

Ok, thank you for the reply. Of course I removed all screws that were visible and I removed all removable parts, which were the RAM and the optical drive. But then I was stuck. Maybe using some muscles might have helped, but as my temperatures were already quite low, I did not expect too much from opening the notebook.
So far I tried NHC, SpeedFan and rmclock but they did not solve my problem, so thanks for pointing out tpspeedfan. If it works for me, I will report back.

Or did you mean TPFanControl by troubadix?

Oops. That is what I meant.

You can set exactly at what temps the fan turns on and exactly at what speed to run it at. Make sure to read the documentation.

I don't remember what exactly was the problem with TPFanControl, but I did not get it to do its job. Maybe it is just for ThinkPads? BTW, the software HardwareMonitor by CPUID says there is a "ThinkPad Hardware Monitor" in the IdeaPad U450p.

I called the Lenovo support line a week ago or so and they confirmed that a) 35°C is very low for the fan to turn on and that b) 35°C for on AND for off might be annoying. They offered me that I could send in my notebook and maybe that's just what I'll do, allthough I would prefer if they just offered a new BIOS on their homepage.