hp6550b no display but loads Windows

[SXTechHead]

Hi all,

I have a probook that worked normally until the weekend. It now powers up and loads Windows XP (I can hear the XP startup chime), but at no point is there any display on the internal screen.

When attaching an external monitor and try to access the BIOS, I see vertical lines of tiny blocks of multiple colours, along with random characters in what looks like a DOS graphics mode. It's reminiscent of the old days (Win 95!) when a graphics card had the wrong drivers.

Also when it loads into Windows, I can SEE the Windows XP logo behind all the vertical line weirdness described, indicating to me that the graphics are not completely shot.

Its an i5 with integrated graphics.

I've tried hard reset, removing and reseating the RAM and BIOS reset (Windows + B key) - no change (incidentally after BIOS reset the caps lock light blinks nine times and machine switches off. Then it powers up again!).

Any assistance from the group would be much appreciated. Thanks.

[Huffer · Accepted solution]

Its a motherboard issue. The video chip is corrupted. The only way to fix is to replace the motherboard. Nice job of diagnostics though. 

[SXTechHead]

Hi Provost,

many thanks for your swift & concise reply.

I shall not waste any more time on it 🙂