VAIO PCG-K33 display goes blank during windows boot

Hi All,

My Sony has a problem that I can't seem to fix so I'm looking for
help.

When I power on my laptop I can see the Sony logo, I can get into BIOS
and I can load MS Memory Checker and still see everything on the LCD
screen. I will call this text mode.

Once the HD begins to boot, before I get the 1st loading Windows XP
screen (the color screen with the little bar graph) the LCD goes blank
(the backlight goes off, I see this because I have taken off the
bezel) but the external monitor still shows the progress. I will call
this graphics mode.

I have swapped the LCD screen (with LCD cable attached) and I swapped
the inverter board, both came from a working laptop of the same
model. I see the same result, once graphics mode starts the screen
goes blank and the backlight turns off.

I then installed the LCD screen (with LCD cable attached) and inverter
board that I just removed into the known good laptop. This time the
LCD screen works fine. Both text and graphics mode work as it should
and Windows XP boots fine and I can see everything on the LCD screen.

I have the laptop set to display on both the LCD screen and external
VGA monitor, both laptops were checked and the setting on both is
correct.

It is not a driver problem because I also swapped hard disks and I get
the same results.

Can anyone suggest anything else I might check?


Thanks for any help,

Charles

 

Hi All,

I should add that if I shine a flashlight on the LCD screen I can see faint images of the Windows XP desktop. That's why I thought the problem would be the backlight. However, since I changed the LCD screen, which contains the backlight, from a known good LCD screen and I get the same results. The backlight turns off once Windows starts to load.

I also know that the problem is not a driver issue because I changed the hard disk, also from the known working laptop, and I still get the same results.

Thus, I am lost at what to try next.


Thanks,

Charles

 

Hi All,

I just got back to working on this notebook and I found the problem. My problem turned out to be a bad DC power board. How it was bad is beyond me, all I can say is that the problem went away once I swapped the DC power board.


Hope this might help someone else later,

Charles

 

Hey Charles, I have the same problem with my dad's Sony K33, but am having a problem trying to find the DC power board, I keep getting mix pictures of it. Can you show where did you get your from? Thanks, Ralph

 

Hi Ralph,

The DC power board is inside the laptop, under the mouse buttons/touchpad. The DC power cable plugs into the power board. I have extra laptops for parts but if you need to buy a DC power board you can try eBay. I have seen them for sell from $10 to $25.

Post back if you have any more questions.


Thanks,

Charles

 

Hey Charles do you have a Sony Part number for the power board?

 

Hi Ralph,

Printed on the board is 'DA0JE5BB8C9' and there is a label on the board with the numbers '#A1071984A 7050587#'.


Hope this helps,

Charles

 

Thanks!!!!