Instructables

Dead CPU?

I have an HP dv7 1130us laptop that recently quit working. One day it worked, and when I went to turn it on the next day it gave me a black screen and the light by the caps lock button blinked every few seconds. Looking on the hp support page for my computer I found that the blink code meant that the CPU had a problem (see here). I tried taking the CPU out and plugging it back in. Then I bought a CPU from ebay (it is brand new) and put it in. Same problem.

When I turn it on the fan comes on strongly then cuts to a lower rpm abruptly. No light comes from the screen. As I said the caps lock and num lock lights flash once every 2 or 3 seconds. The light by the power plug stays on solid. I am not sure how it could matter but I should also mention that we got a new wifi router the day before this happened. There is other helpfull information here.

Do you have any ideas about what might be the problem?

Vyger2 years ago
I have a notebook that a customer gave me to look at that is doing almost the same thing. I think its the motherboard that is semi dead. It still gets power and the power circuits work, which is why the fans work (probably still has power to the USB also) but a component on the main board is dead. The screen gets power but never displays anything.
I tried a test card but since the board is inert it doesn't do anything beyond powering on. You can get these things really cheap now and you might get one just for curiosity. The notebook ones connect to the board by removing something like the wireless or bluetooth and plugging them into the slot. You may not find a slot to plug them into on all notebooks.
I think the problem with this one is the BIOS, I think the Chip went bad. It might be the same for yours and there is no real way to replace it that I know of.
Jaycub (author)  Vyger2 years ago
OK. It sounds like you know pretty well what you are talking about, especially since you have customers. So if the BIOS chip is bad I might as well get a new computer because a motherboard from HP is like ~$320 I think. Thanks for your advice.
lemonie2 years ago
Did you try the memory before buying another CPU?
Did you mess with it in any way at all unusual? (plugging a router into it probably isn't it if it still doesn't work with it unplugged)

L
Jaycub (author)  lemonie2 years ago
Thank you for your comment. Yes, I unplugged everything when I tried "reseating" the original cpu. I haven't tried it with just one ram stick in though, I just learned of that test today. There was nothing unusual done to it before this happened.
lemonie Jaycub2 years ago
Weird, well let us know if you fix it.

L
Jaycub (author)  lemonie2 years ago
I figured out that I have no clue if it is even possible to fix it, and that I can build a computer that is a lot better for ~$260 so that is what I am going to do I guess.
lemonie Jaycub2 years ago
Yes, sometimes starting again works best, best wishes with it.

L
emuman4evr2 years ago
If the motherboard has one of those little CR2032 button cells on it try pulling it out then waiting for a little bit then putting it back in. This fixed one of my previously "dead" computers.
frollard2 years ago
Try unplugging then re-plugging all hardware, could be a simple loose ram chip...if both cpus are acting up, could indicate a few problems with other components (like video card)
Jaycub (author)  frollard2 years ago
Thank you for your response. Everything was unplugged both times I took it apart. You think it could be the video card? I had thought that was possible because nothing came on the screen. How can I test if that is the problem?
frollard Jaycub2 years ago
I don't want to say buy another card (particularly if it has integrated video) -- might just be a dead motherboard in that case;

Without the ability to test the components it is really hard to say. How does the computer boot with only one ram stick inserted (if multiple), and/or the other.
Jaycub (author)  frollard2 years ago
I'm kindof thinking it's the motherboard at this point. I tried the ram experiment but it didn't help. I guess I'll open it another time and try to identify and mess with the video processor.
Re-design2 years ago
TAke everything off the computer except power supply, vid card, memory, hard drive and cpu. Try to boot. If it boots then your vid card and everything you have on the computer is probably fine. Not add in the rest of the stuff until you find one that causes it not to boot.

Now if it didn't boot then find a replacement vid. card to try.  It if boots now then your orig. vid card is probably bad.

If it didn't boot with the replacement card then replace the original card and try a different power supply, then memory.

You have to isolate the problem to just one item by substituting parts until you find the bad one. 

It could be a bad harddrive, cd drive, memory, powersupply, motherboard, and card that is plugged in, etc.  The diagnostic beeps are just a starting point and are often wrong.