Presario 4540, freezes during POST

“Presario 4540, freezes during POST”

“Presario 4540 AMD K6 233 MHZ
Phoenix Bios 4.0 Release 6.0.I

Computer locks up during POST. I have to turn power (switch on power supply) off and on 3 or 4 times before computer gets through POST and boots. This happens regardless of whether I restart computer from windows, turn computer on from a windows shut down, or turn the power off and on from the back (power supply).

When the computer locks up during POST, the following appears on the screen:

00000640k sytem ram passed
00031744k extended ram passed
DMB upper limit segment address:

At this point it locks up. On the 3rd or 4th time of powering it off and on, it completes successfully and boots. The POST screen is as follows:

00000640k system ram passed
00031744k extended ram passed
system bios shadowed
video bios shadowed
UMB upper limit segment address: F26D
mouse initialized
atapi cd-rom: LTN202
fixed disk 0: Quantom Bigfoot

Now, when it fails I have “DMB upper limit segment address” rather then “UMB upper limit address”. Any ideas why. I’m assuming this has something to do with it. Bios is currupted?

After a successful boot, computer runs fine with no further problems.

I have:
1) unplugged and replugged all ribbon cables
2) reseated memory
3) replaced battery
4) tried starting without modem and nic card
5) put them back in and tried it again
6) flashed bios
7) fdisk, format, reinstalled operating sysem
8) ran both “burn-in” and “DocMemory” diagnostics on memory with no failed results.
8) changed jumper to pins 2 and 3 to clear CMOS then put it back on pins 1 and 2.

These last two things I tried in different order to no avail.”