Monitor going to sleep during XP boot up

Hi,
I’m trying to repair a PC that’s built into a scientific instrument.
It’s running Windows XP.
The motherboard has the following connections excluding power:

• Hard drive - IDE
• DVD - IDE
• Thermal printer - parallel port
• Touch screen - VGA port & COM2 header
• 2 x USB connections to the instrument
• 1 serial port to the instrument
• DDR333 512MB RAM
• It also has a PCI modem for some reason.

The problem I initially had was that it kept rebooting almost immediately after it was turned on.

I replaced the capacitor that had started leaking and the BIOS battery as it then had started complaining about that as well.

After this it is behaving a lot less irrationally. It is now booting up to the point where a white horizontal status bar is moving from left to right at the bottom of the screen. However, as soon as it moved all the way to the right the monitor goes to sleep.

I have tried installing a recovery backup of the instruments hard drive onto a different hard drive. Same result.
When I installed a clean version of XP on to the new hard drive, the monitor went to sleep as the Windows XP screen came up and the blue status bar was moving.
I have tried with different monitors, and a different power supply.
I haven’t found a RAM stick old enough to try yet.

What I forgot to mention is, that I have run all these tests on my bench without the instrument connected. I have also removed the PCI modem and the printer from the parallel port.

It also seems that at some stage, probably when a replaced the BIOS battery, the BIOS was reset as the date in the BIOS is sometime in the early 2000.

If you have any ideas or can point me in any direction, it be greatly appreciated.

 

https://duckduckgo.com/?t=palemoon&q=monitor+goes+to+sleep+after+booting,+windows+xp&ia=web

Please check out the links on the above page for the same issue that you are experiencing.