Hi,

I have a HP ze4540us laptop.

2.4mhz intel mobile cpu (not celeron)
1gb ram
40gb hdd
cd/dvd
internal wireless card.

Something shorted out a while ago, and the MB died. I bought a used MB off ebay, hoping to get the thing back up and running again. The new MB is from a compaq presario 2100, and has the same part number as the HP MB I was looking to replace. I didn't buy a tested-and-guaranteed-working MB because the prices are higher than the current value of the laptop. So I am looking for a cheap DIY fix.

The new MB has an intermittent power failure problem, I have had times where I can get it to boot up all the way into windows XP, and function properly until I shut it down.

Mostly however, when I try to power it up, the computer begins booting for about a second or two, and then shuts off for about 3 or seconds; and then repeats this process for about a minute, after which it just stays shut down. During these short "on and off again" cycles, the computer never reaches any kind of display screen at all (no post/bios).

I have tried reseating the ram/hdd/dvd, resetting the cmos; removing just about every removable component, and attempting startup.

Any suggestions on what is going on with this mb, and is it repairable, or should I just give up and look for another mb?

You probably got screwed and replaced one bad mobo with another.

Can you think of any reason why anyone would sell a good laptop motherboard? It is not something that you can upgrade and sell the old one or sth.

The replacement MB was not sold as a "tested & working" mb; I went into it knowing that the seller listed it as "untested" and quite possibly dead. So I was not "screwed" on the purchase; I knew I was taking a chance.

Sill, after replacing the old totally dead & fried mb with this "untested" one, I have been able to boot up the laptop [sometimes]; reformat the drive, and reinstall the original version of Windows (XP Home)... I wanted to get at least that far, to remove any personal info from the hdd, if I decide to just sell the laptop in its current [working intermittently] state.

In looking on ebay and other places for parts for this specific laptop (HP Pavilion ze4540us; Compaq Presario 2100); I have come across more than a few being sold 'as is', where the seller describes the exact same problem I am having... Laptop powers on for a second or two, fan starts, lights blink, etc... but the boot sequence never reaches POST (bios screen) before it crashes (shuts down), and then after a few seconds, repeats this process over and over. Also, this problem is not confined to the specific model numbers listed above; I have read incidents of several other similar HP/Compaq models exhibiting the same problem behavior.

In posting here, I was hoping that the problem might be common enough that someone had heard about the issue, and knew of a potential fix.