Resolved Laptop keeps trying to start (for a couple of seconds) but cannot

My Compaq Presario V6700 laptop keeps trying to start, but cannot. It turns on briefly and the fan starts, but it then stops after a second. About five seconds later, it tries again with the same result. It keeps trying until I pull the plug on both the battery and outside power. The power light comes on, and the CD drive light blinks on, but the disk drive light does not even flash.

This happened after I took the laptop apart to fix the screen. I had the keyboard off, and the screen display was disconnected. I hooked the laptop up to a monitor via the VGA port so that I could use it.

I've tried reseating the memory, and putting the laptop back together as much as I can. No luck there.

Any ideas?

 

Thanks for the reply. I took out hard drive, CD drive, and memory, and replaced them, and there is still no change.

The laptop's clearly not getting very far before it hits a problem. The power lights come up, the fan starts turning, and the CD drive light turns on, and then less than a second later everything turns off again.

The odd part is that the laptop keeps trying to start again. I've never seen that before.

The only thing I can think of is to get a SATA to USB hard drive adapter and see if I can access the laptop's hard drive from my desktop. But that will take me a couple of days. And I really need to get some files off the laptop now.

Guess this just shows that you can never trust computers to be there when you need them. An important deadline always seems to bring out something like this.

UPDATE: I took out the hard drive, took out the CD drive, took out the memory sticks, and then tried to start the laptop. Still the same problem. No change at all. From what I can see on the Internet, that means a motherboard problem, which is probably beyond my ability to fix on my own.

Does a motherboard problem sound right?

 

Hi, did you download the Service Manual before you dismantled the laptop?

I have a Compaq Presario which I was given in non-working state. I downloaded the manual before attempting to dismantle and found quite a lot of info advising extreme care. I have had this unit apart at least 6 times to replace CPU, cooling fan assy, RAM, Hard Drive, Battery, keyboard assy to get it successfully working again.

Length of screws securing parts and motherboard to case - being one example. Incorrect positioning of some of the screws can short out and cause major problems!

Like Pete said, it's difficult to even make suggestions, but if you don't have the Service Manual, I would strongly advise you to get one and read it thoroughly to see if there is anything there that you might have missed when you dismantled it. Cheers Neil.

 

Yes, I did download and have been using the Service Manual. I had to replace the cables to the laptop screen and inverter, which is why I had the laptop disassembled. I was pretty careful to follow the manual, and some website illustrated steps, but I may, of course, still have done something wrong.

When the laptop gets almost nowhere before crashing, it is hard to tell what the problem is. I can see the light on the CD drive flash on before the laptop dies, but as near as I can tell the hard drive light does not flash.

As mentioned, I stripped the laptop down to just motherboard, CPU and memory, and got no better result. That seems to rule out anything but a motherboard problem, but I wanted to see if anyone had any advice otherwise.

 

Dannii, this is unlikely to help but still worth a try for no investment (other than your time)...

Rebuild the laptop, remove the battery and mains power source, then press and hold power button for ~30 seconds. Insert battery and/or mains and try it now.

As I say, unlikely in this situation but you never know.

 

Thanks for the suggestion, Wildfire. I tried it, and as you suspected, it did not help.

But I'm always glad for things to try. So thanks again.

It's strange. I've found several posts from people who had the same problem. But no one who replaced the motherboard and then reported back that that had solved the problem.

I'm about ready to order a new motherboard and replace this one. But I'm a little worried about the graphics card. I'm not sure how that fits in. I'll need to research that first.

 

It sounds very much like a short which will cause a heat problem. A slight cooling and it will try again.There is very little you can do if it's in the motherboard.
From your info - you haven't touched the CPU or cooling fan?
May be coincidental but I would take out the CPU and carefully clean and renew the thermal insulation (paste or pad) and reseat the CPU and fan just to see if that helps before tossing the motherboard south. Neil.

 

That's right, Neil. I never touched the CPU or cooling fan.

I'll give your suggestion to reseat the CPU a try. I'm out of town all next week, so it may have to wait until then. Thanks for the suggestion.

 

Thanks for your comments, Arie. As you suggest, I'll try Neil's suggestion first. But I have found a motherboard that I believe will work. I'll confirm that before ordering.

 

Good point, Arie. It looks like I probably need a different board anyway, like this one. But I'll check for sure when I get a chance to take the laptop apart.

It may be wise to get a new board, as you say, especially since these laptops apparently often have a problem with the nVidia graphics card. Apparently there was a litigation settlement. Best to be careful.

 

Thanks for the information. That's good to know. Sorry to hear that you had the problem, but glad to know I do not.

 

I've been out of town, and now too busy with work to work on this laptop. But I still plan to take apart the laptop and see if reseating the CPU helps. If not, I'll probably try the new motherboard.

Thanks for all the assistance.