Computer Hardware Gurus...

was the CPU removable or was it soldered in?

 

likely the video card or bad RAM if the MoBo replacement didn't work

 

On a notebook computer the video card and video ram are on the motherboard, so these should have been replaced with the motherboard.

This leaves two likely areas for the failure: 1) The LCD display system, or 2) The system power supply. My first suspicion is the LCD display or connectors leading to the display. Without being able to boot, you can't switch the output to the external monitor, so that not working doesn't really tell us much.

Pull the RAM, hard drive, and anything else you can remove not related to power. Once you have done that, try booting. A computer can't boot without those parts, but you should see the BIOS come up if at all possible.

Tom

 

I would think its the CPU then because you said it was blinking once. According to the blink code its the cpu. If you look at the under side of the cpu do you see a dark spot in the center? Thats if it does not have any pins in the center.

 

Even if a CPU over heats, you can usually get it to power up for a short time, before it shuts down.

I am a compuer tech, and have seen many things happen to computers. But I will admit, I am puzzled by your issues. Especially with you replacing the motherboard.

If you want to replace the CPU, get one from ebay (if available) to save money. And if you ever need to replace a motherboard, search the internet. Only go through main company websites if you have no other choice. I have found many replacement parts through various online stores cheaper then brand name companies.

I am sure you know how, but I have to ask. Do you know how much thermal paste to put on the CPU?

I used to recommend HP for people to buy, but I have seen too many issues lately, and no longer recommend.

If anything else comes to me, I will let you know

Are there any audio beeps that occur?

 

Yes a dark spot in the middle would be due to overheating but with these new cpu's with pins all over the bottom its getting hard to tell if they are damaged from overheat.

I still think it would be the cpu. Do you know anyone that has a good spare you can borrow?

Personally at this point I would just try to sell the parts and get a new laptop.

This is the reason I dont fix laptops besides a ram or hard drive upgrade. A new one would be about the same price or a little more than trying to fix a bad one. They are nothing like a desktop. You cant just swap out cheap spare parts to see whats really wrong with them like you can desktops.

 

Yea. Laptops can be a pain. I have completely disassembled and reassembled several laptops. Sometimes it is worth it, and sometimes it isnt

 

The blinking you describe sounds like it might be the board starting up and then resetting, over and over again. That's not a blink code. Insufficient power is one possible cause, although the AC supply usually will run the thing even with a dead battery. But if it can be run with the battery removed, try that. I have rarely, if ever, seen a bad CPU except where someone fried it through carelessness. I did fix a friends laptop recently, and nearly wound up with a brick like yours is. Fortunately I checked the memory, and I had not seated it all the way. It came to life after I put it back in properly. That made him happy.

 

Sounds fried. I never would attempt to fix anything like that. You could have got a decent MSI motherboard and CPU from Tiger Direct, and had a new system with better performance, for what you put into repairs

EDIT

Whoops, this is a laptop, not a desktop. I've never tried fixing a laptop, they are a "throw away" item

 

Pull out the CPU and boot it up to see if the blinking stops. If the pattern remain the same, you can rule out the CPU.

It will then point to the power supply.

 

My first suggestion: Set up a work area where you can leave it disassembled. Then take it apart, and only hook it up enough to see if it works after trying something - don't put it completely back together again until it's working. This will save a LOT of hassle...

It sounds to me like the CPU is bad. I've seen them go before from overheating, and other issues (in fact, I had a friend once who burned one out from an ESD caused by dust in his machine!).

Frankly, I probably would have taken the thing apart and hung pieces on my wall before this point... but that's just me

 

I've replaced the screen on laptops before, not a big deal, if you hook up an external monitor and try to boot and it shows the boot sequence then you know its your screen, I mention this because I don't see that you had tried it yet...
I'm running windows 7 and for the last three weeks if I let windows update my computer on restart no monitor so I reset the system to an earlier date to get rid of the update and my monitor comes back...
just saying

 

He already tried that, from his first post:

 

Mybad, Doesn't say that he tried rebooting a few times, I would unhook the monitor. hook the external monitor and try to boot
HP Pavilion dv5-1125nr's are 550$ new...

 

i vote bad MB, CPU or power supply. i know you have replaced MB, but no replacement is guaranteed.

also, you hooked up external monitor. not all laptops can provide video to external port if not provisioned in BIOS first. might also be a jumper setting on MB to enable.

it is still unusual to not get even BIOS screen which usually points to bad BIOS, bad motherboard or bad power supply.