Compaq Presario 1800T no video


May 31, 2016
Compaq Presario 1800T is an old laptop I know, but I really want to try to get it working again. My issue is there's nothing on the screen, and external VGA isn't working.

Since HP isn't showing all the laptop's specs, here is some of them.
- Pentium III proc.
- ATI 3D Rage M-128

If you need a motherboard picture, I can post that.

The Pentium III is on the top of the board, the 3D chip is on the bottom. I've seen lots of posts similar to this that say to reflow the GPU if you don't get video. So I tried a heatgun set to 300 Celsius on the GPU for 5 minutes. Nothing fixed. Then I tried it on the CPU and other chipsets and around the board for about 5 minutes roughly. Still nothing.

Also pulled out the CMOS battery, tested it, still good. Pulled out the ram, nothing changes. Tried a few different power bricks too.

The fan spins, I can press the DVD tray button to open it, the HDD spins up, but that is it. Also the keyboard lights like capslock and numlock do nothing. Left the laptop on for 15 minutes, it never shut off so it doesn't have a heat issue.
It might be the screen's backlight that's blown/burned out.

With the laptop running. look very closely at the screen while shining a torch on it.

If you see a faint image of the boot screens or Windows image, then it's definitely a blown backlight (which can be replaced either by you, a competent friend or a at laptop repair shop.