Lenovo G550 video problems

I may have asked about this before, but there were no replies, so I'm really hoping to hear from another owner of this lowly machine to confirm that mine is a rogue.

In normal use the machine is fine, with a good clear display and no obvious problems except when I fire up Windows Media Center in full screen mode. Then I get a line about one third of the way down the screen and below this line terrible tearing of the screen display occurs. If I come down from full screen mode, the display is fine except.......

I have discovered that sliding many windows to the left so that the left edge of the window is way off the screen, the same sort of tearing occurs. The effect depends to some extent on the content (eg colors) in the window, and varies from just a little trailing tail on some graphics up to full blown unreadable display failure.

I have tried with all the updates I can find for the Intel Series 4 Express chipset, and also with the basic Microsoft vga driver. This won't support the screen resolution, but I can just about trigger the effect in a minimal way.

The machine is Win7 32-bit and has all the updated drivers from Lenovo.

If I load the current version of Ubuntu and run it from a usb thumb drive, I can trigger just a hint of the same effect.

Is there anyone here with one of these machines that can test and confirm that I have a faulty machine, or even suggest a reason?

 

Does it do the same thing externally?

G550 as I recall should have the 4500MHD, download Intel's latest driver. Lenovo sometimes will have older drivers.

 

I can't easily do a meaningful external test as my desktop monitors are all the 800x600 aspect ratio rather than these stupid wide things we are now stuck with on laptops. I'll have to try to borrow a monitor. Thanks for the suggestion. I hadn't thought of that.

I have tried all the latest Intel drivers for the Mobile Series 4 Express (which is how it is identified in Device manager and on the Lenovo and Intel sites. If I bring up the available drivers installed options via the Update Driver thing in Device Manager, I have all the drivers I've downloaded and tried since I got the machine - about 7 options including the last one from only a few weeks ago. None of these make any difference.
I've reverted to the last driver on the Lenovo site because that makes the machine more "standard".

 

As I suspected, I can't do sensible tests with my external displays as I haven't got a monitor that matches the resolution of the G550. The nearest monitor is 1280 x 768, and that doesn't sync the picture centrally on the screen on the monitor.

When I have the laptop set as the primary display, I end up with the Refresh rate of 60Hz for the laptop and 75 Hz for the monitor, and the processor running at 100%. The two screens seem OK at first, then the monitor display slips sideways.

But I suddenly thought of someone with a high resolution monitor, and rushed over to do a very quick test (they had to leave to catch a train). With this, the laptop set itself as the primary display and the display synced up within the larger monitor screen. I was then able to invoke tearing on the laptop screen but the monitor display remained clear and readable.

The question now is what does this mean?

 

which version of bios do you have?
Lenovo Support - Drivers & Downloads

 

The bios version as listed in System Information is "LENOVO 18CN44WW 2.53, 19/04/2010". The version numbers appear to confirm it is the latest version, although the Lenovo support site says "Last modified date 2010-06-11". The Readme refers to a date of 04-20-2010, so maybe the last modified reference is to the website rather than the bios.

I have just returned from a wife&daughter shopping trip where I found the identical G550 in a Staples store, and confirmed that it behaved normally, unlike mine.

I do see that there is a 64-bit version of the bios with all the same version numbers, and I've trawled through the bios itself and the System Info without finding any indication that I definitely have the 32-bit version installed.

Maybe I should try re-flashing the bios?

 

If you can't replicate the issue on the external monitor, then seems like you may have a defective LCD/LVDS cable or something wrong with the connector on the motherboard.

Is your IdeaPad still under Lenovo warranty?

 

I have now flashed the bios with a new copy of the correct version, and the fault is still there.

The machine warranty expired in December. Unlike my other Lenovo, I can't find a Hardware Maintenance Manual on the site, only a user's manual.