Thinkpads Forum

I've just noticed that the LCD on my T42p produces a buzz/whine when set to anything less than 100% brightness. It almost sounds like a mechanical noise, such as would be produced by a fan that was rubbing up against something.

It is not, however, fan noise. It goes away when I hit Fn-F3 to turn off the LCD. It also seems to respond to pressure on the lower-right corner of the screen, and is quieter at some brightness settings ("4 bars" is quieter).

At 100% brightness, the noise stops altogether. However, since the max brightness when running on battery is set to less than 100%, it's noisy all the time when not on AC power.

Has anyone else experienced this?

If you plug in "lcd AND whine" into the Search link at the top of the page, you will find 14 hits. Some of them discuss this issue.

Yup - sounds like it might be a "singing" inverter, given the behavior I described above. Don't know how I missed that in my previous search.

I suppose that it just started singing recently because it's getting old. (Although I did have the backlight replaced about six months ago. I don't know if they did the inverter at the same time or not.)

I suppose at < $30 on eBay, it's worth trying to swap the thing out myself. I even googled up a guide (specific to the T41): http://www.laptoprepair101.com/laptop/2 ... backlight/

Are you using an IBM or 3rd party power supply. This happens to me w/ the 3rd party supply, but not IBM. The 3rd party supply has a 3 prong adapter, while the IBM is 2. might be related to that.

roberts5 wrote:Are you using an IBM or 3rd party power supply.

All stock power (batteries & power adapter).