View Full Version : boots to a blank screen
law9933
06-15-2004, 05:48 PM
Trying to install XP. Posts then stops at a blank screen. Pwr off by holding button in. Restarts to select Safe, Last Known, & Start normally. Select Start Normally & it bootsup- works fine. Restarts OK until !st initial pwr on after a time off. Tried HDs, CMOS battery, 2 XP CDs, HD is 1st device in bios. Can this be caused by both software & hardware? Seems like something needs a second chance to get motivated.
Thanks Les
Sylvander
06-16-2004, 04:18 AM
1. Did this PC previously startup normally untill you installed WinXP?
2. Do you hear the single short beep indicating successful completion of the POST, and then instead of the 1st display of characters you get a black screen?
3. Does all activity halt at that point?
Here's the appropriate point in the "BIOS Boot Sequence":
3. The BIOS performs the power-on self test (POST). If there are any fatal errors, the boot process stops.
4. The BIOS looks for the video card. In particular, it looks for the video card's built in BIOS program and runs it. This BIOS is normally found at location C000h in memory. The system BIOS executes the video card BIOS, which initializes the video card. Most modern cards will display information on the screen about the video card. (This is why on a modern PC you usually see something on the screen about the video card before you see the messages from the system BIOS itself).
This is rather mystifying but how about this for speculation:
a. If you had [in the default configuration settings] "Video BIOS Shadow = Enabled" in the "BIOS Setup->BIOS Features Setup" so that the video BIOS was being copied to a location in RAM and operated from there. [This is done to speed up the operations of the video BIOS. RAM works faster than the BIOS ROM.] Then if some other device was trying to use that memory location and had locked it, then your video card BIOS would be unable to function. Needless to say, you'd get no video display under these circumstances.
I wonder if the operating system is detecting the conflict and disabling the conflicting device, so the video works next time around.
SOLUTION
When the PC normal startup succeeds the 2nd time around, go into the BIOS Setup and disable video BIOS shadowing and see if that fixes the problem. If it does, this fix will slow the operation of the video BIOS, so you need to search for the root cause [the conflict for the use of that space in RAM].
Sylvander
06-16-2004, 05:25 AM
See this http://www.pcguide.com/ref/ram/logic_Shadowing.htm
I remember someone saying that this is no longer the case these days.
That ROM shadowing is no longer used because RAM is no longer faster than BIOS ROM.
That's not to say that your particular BIOS doesn't have the facility for video BIOS ROM shadowing.
See this also http://www.pcguide.com/ref/ram/logic_UMB.htm
Where it says at the bottom of the page:
"Warning: ROM shadowing should be disabled in the memory vicinity where EMM386 is using the UMA for UMBs, or problems will result."
law9933
06-20-2004, 02:39 PM
My daughter had it-Gateway, MB is MS-6330 2.1, AMI bios. It had a 10G HD & ME. Seems the problem was similiar then. I had hoped a new&better OS and HD would be the fix.
It posts (flashes info), 1 beep, then fails to (refresh?) into the Windows screen until selecting-Start Windows Normally. I did not find any video settings in Bios but I'm just learning.
In Properties>Environment>System Variables the OS is Windows_NT. I would of thought it should state XP.???? Thanks Les
Must be a hardware problem?
Paul Komski
06-20-2004, 04:19 PM
It doesn't state the version of NT there - and WinXP is a version of WinNT. Win2K is WinNT 5.0 and WinXP is WinNT5.1 (http://www.computergripes.com/Microsoft.Product.Names.html)
RClick MyComputer > Properties > General Tab to see which "flavour" of Windows is installed.
then fails to (refresh?) into the Windows screen until selecting-Start Windows Normally
There are many possible causes of your problem (bad or badly-seated RAM being just one) but, for example, with an older monitor or without the correct video drivers you may have problems of this sort. Booting into base video should identify these areas if you are then able to boot successfully first time.
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