HP Pavilion dv7, black screen, blinking LED

solution: put the PC in the freezer for a few minutes, then start it up; if it starts, the BIOS is probably defective and there is an update on HP that fixes the problem.
I just got two back up and running after this issue.

I had the same problem with two HP laptops and it’s basically a motherboard issue, it’s dead, and the only options left are to replace it or buy a new laptop. If your computer doesn’t start anymore and multiple lights turn on, it’s the motherboard, and the same goes if your computer turns on after several attempts to start it. This problem seems quite symptomatic of HP computers, regardless of usage and the age of the laptop. The manufacturer, Packard Bell, and especially their customer service, to whom I sent several letters of complaint, claim that it’s a humidity problem. Of course, they blame everything else and don’t take responsibility for the absolutely poor quality of their products!

Hello,

solution by resetting the BIOS using the following method:

1- remove the motherboard cover
2- take out the CMOS battery
3- press the power button for about 15 seconds to completely discharge the capacitors
4- put everything back in place
5- start the PC

Yes, so you need to remove all the screws and take a piece of paper to draw the laptop and mark the placement of the screws and put them on it because there can be screws of various lengths. Generally, the strip with the LEDs + speakers + power (below the screen) is clipped, so be careful during disassembly and be meticulous.
I'm not a computer technician and I've already disassembled over 30 laptops of all brands... and I succeeded.

The process is unlikely, but you can test it on another laptop.
The dv7 models, like the dv5 and dv6, tend to have motherboard failures.
I found a used motherboard on a website (Leboncoin) for 50 euros (the seller had broken his screen) you need to find the model, but you have to be patient..
Otherwise, the website "Micro Puce" sells new or refurbished motherboards.

You have to know how to bring it back up afterwards!

I got this, try to put the rams back in place.

Correction: the codes are only valid for devices purchased after 2009.

Hello, I had a colleague at work with a DV7 who apparently had the same issue as you, it's the motherboard that is dead.
The fan works and the hard drive seems to be spinning?

Yes, the fan is running and the hard drive too, I also suspect either the motherboard or the processor...

Thank you. With the CMOS trick, my HP is now working normally. Well done!!!