HP dv2500t wouldn't power up

I was one of those unfortunate people who bought HP dv2500t with nVidia overheating problem about 2 years ago. About 3 months after my 2-year extended warranty expired, my laptop started having problems with the screen that split into 8 parts and showed lines running across. Unfortunately, HP was of no help since my laptop wasn't on the list of those recalled and asked me to pay an extra $400 to get it repaired.

After doing research on the net, including this site, about this problem, I decided to replace the motherboard myself. I ordered an exactly the same motherboard that came with the same nVidia chip from a reputable seller who specialized in selling used motherboards. He assured me that it was tested and even recommended adding a piece of copper on top of nVidia chip. So I carefully took apart the laptop, added a piece of copper that came with the new MB using instructions posted on this forum (with Arctic silver 5) and reassembled it.

To my surprise, the laptop wouldn't power up. When I plugged the charger, the blue LED light would go on both the front side and the right side where the charger goes. And then there were no other signs of life from the laptop. I thought maybe I didn't connect some wires properly. So I disassembled and reassembled the laptop 2 more times. All to no avail.

I can't for the life of me figure out how to diagnose where the problem is now. Everything, except for the video was working before. Now, I can't even power it up.

Any help would be greatly appreciated.
Thanks.

 

well it means that the motherboard you just ordered is bad...If I am you I would contact the seller to get a replacement

 

What makes you so sure? Is it possible that there is a poor connection somewhere or a short-circuit?

 

well you said you double checked all connections and still nothing..replacing a motherboard is straight forward by just connecting all the cable. Thats why I think you probably got a bad motherboard. Try putting back the old motherboard to see if it turns on.. if it does then that will give you enough evidence that the new motherboard is bad. But if it doesnt then one of your power cables is shortout or broken..

 

I forgot to mention that I had to replace one power cord - the one that connects the power button to the mb. I ripped the old one while taking the laptop apart the first time. Is there a way to test that cord to see if it's damaged inside? Because on the outside it looked fine.

P.S. Putting back the old mb is not an option. I played around with it after I took it out. It's probably been damaged by static electiricity. Besides, I pulled out some things from it.

 

If you don't mind me asking, where did you get it from and for how much? Thanks.

 

If you are talking about MB, I got it from eBay for about $150. The guy I bought it from must have sold hundreds of them, mostly from HP.

I see you have the laptop with almost the same configuration as mine. I even did the copper mod, but wasn't able to bring it back to life.

 

You have either a bad cable or a bad power button. Try touching the Quickplay button and see if it powers up.

 

My laptop doesn't respond to any buttons pushed whatsoever. Yesterday, I plugged it into the power outlet through the "Kill A Watt" device. Although the blue LED lights were on, it wasn't drawing any power from the outlet because "Kill A Watt" showed zeros.

 

I am taking part of it back. When I connected the laptop through the AC adapter, "Kill A Watt" registered 35W. Then, I took the battery out, wattage dropped to 0, which means the battery was charging. The problem has to be somewhere inside.

 

Then there are chances that your new board's a dud too.

 

Before I completely give up on this, I am going to take it apart one more time and connect it to the power source while the laptop is disassembled. I read that all you need for the laptop to power up is the CPU, memory, and power source. Hopefully, it powers up in that condition. If not, I'll sell all working parts and throw out the rest.

I am planning on getting a replacement laptop soon. I have Intel Core 2 Duo T7300(2.0GHz/4MB L2 Cache) processor
http://processorfinder.intel.com/details.aspx?sSpec=SLA45
It's a pretty powerful CPU even by today's standards. Do you know if I can swap my old CPU with Intel T4300?

 

You also need the ribbon cable that goes from the power button board to the mobo, otherwise it won't start (obviously because the power button has nothing to send the signal to).

 

I've got great news!!! I finally got my laptop to power up. You'll never guess why it wasn't powering up. All HPs fault.

Here is what I did. Like I said in the previous post, I disassembled it again and connected the power to the bare bone machine(I was encouraged to do so by one guy on another forum, who tested his laptop this way). To my surprise it powered up. That meant the MB and the power buttons were good. Then I started assembling it part by part, wire by wire while checking to see if it would power up. Unfortunately, in the process I ripped off the top part of a plastic wire encloser for a wire that connects the screen to the MB. But I managed to stick the wires back in and covered them in protective tape. Anyways, the laptop stopped powering up as soon as I connected the touchpad. Do you know why? My laptop has a fingerprint reader on the right side of the laptop. On the MB, there are two identical connectors - one for the fingerprint reader and the other for the touchpad. They are right next to each other. Naturally, I thought I was supposed to connect the left wire for touchpad into the left connector and the right one for the fingerprint reader into the right connector. However, geniuses at HP thought otherwise - the two are supposed to be criss-crossed . From the design point of view it doesn't make sense. I didn't remember how they were connected originally and couldn't find anything anywhere about how to connect the two, though later I noticed "tpad" in tiny letters underneath one of the connectors.

By the way, I bought my replacement MB from this guy on eBay. He actually included a piece of copper for the copper mod I did.
http://myworld.ebay.com/yyoo67890/

Thanks to all for your help and good luck with your laptops.

 

Good catch. I've seen so many stupid things while taking apart or troubleshooting HP machines, that it doesn't surprise me at all. Yes it makes no sense from YOUR design standpoint, but it probably makes from theirs.

You know why? They're too greedy to get FIVE DAMN RIBBON CABLES custom made, so they order standard cables, and bend the sh*t out of them so that they fit. That's why they break so often.