HP G62-372US won't turn on.

[eroc263]

Hi everyone. I'm having an issue with a G62 not wanting to turn on. I am getting a charge indicator but when I press the power button, the power and F12 (wifi switch) lights blink together. The blinks come every 5s or so and will continue until the charger is removed. I have noticed with the laptop partially disassembled the first initial press of the button will sometimes cause the CPU fan to briefly spin(less than 1s). No beeps, nothing. I am new to troubleshooting computer circuits but I have basic electrical knowledge and have experience building and configuring PC's. I have the luxury of having access to a known good G62 of the same exact kind. I also have a friend that repairs Avaya ACS modules and can replace/swap ICs, capacitors, etc. I am considering trying a new bios chip but I just wanted a little input from someone with more knowledge and experience than I. I don't really want to replace a $100+ motherboard when I can reball a board or replace a $5 IC. Any help will be greatly appreciated. Here's what I have checked so far...

-I have power to the mobo
-Have checked the charger and battery against a known good G62
-Tried removing everything and holding power button for 30s.
-Removed and reinstalled CMOS battery
-Swapped RAM and HDD

Also, could someone point out the BIOS chip on my board. I've uploaded a pic below.

[Francisco.s]

Re: HP G62-372US won't turn on.

If you have an identical functional motherboard, read the contents of BIOS chip, with Bios Backup Toolkit, and reprogram bad motherboard with it, or swap the bios chips. (you need a bios programmer in the first case)

[eroc263]

Re: HP G62-372US won't turn on.

Swapping chips would be the easiest option for me currently as I don't have a BIOS programmer. I have found a few cheap options on eBay if it proves to be the problem. I just don't understand how the BIOS could prevent the laptop from even powering on. If you know, would you point out which one is the BIOS chip? I see two Winbond 8pin chips that are on opposite sides of the board from each other. I'm guessing its the one closest to the CMOS battery but I'm not sure. If I can figure this out I will attempt to swap chips today. Thank you for your input.

[whaldsz]

Re: HP G62-372US won't turn on.

Select the one near your SIO (ENE) chip.

[eroc263]

Re: HP G62-372US won't turn on.

Select the one near your SIO (ENE) chip.

Thank you very much. I will post my findings after swapping the BIOS chip.

[eroc263]

Re: HP G62-372US won't turn on.

No luck with swapping the bios.

[spleenharvester]

Re: HP G62-372US won't turn on.

You sure it was deffo the BIOS chip you swapped and not a MOSFET or CMOS storage chip? (it's easily done)

But it does sound to me like there's a short somewhere. I'm experiencing a very similar issue with my Toshiba L500. I'll take a look on the schematic later for you.

[whaldsz]

Re: HP G62-372US won't turn on.

What are the pin voltages of your bios? Do you measure 3.3v and 5v in some of the coils?

[eroc263]

Re: HP G62-372US won't turn on.

I replaced the 8pin chip to the left of the ene chip as instructed in an earlier post. Is this not the bios chip? Also I haven't checked any pin voltages as I don't have a schematic to know which pins should read what. The only thing I know to do from here is check readings on the known good board against those of the non functioning board. Thanks for all the help so far.

[Techie666]

Re: HP G62-372US won't turn on.

I had a similar issue with an AMD version of the board, turned out it was the kbc controler (KB3926) but bios is also a common failure. try this schematic see if it matches your mobo:

https://docs.google.com/file/d/0Bz6N...it?usp=sharing

according to this schem, it appears your EC bios is U2

you could build the LPT programmer

https://www.badcaps.net/forum/attach...1&d=1377112567

its cheap and it works pretty good using spipgm. just make sure to use short cables and include a /d=10 when programming to avoid errors. the main problem is getting a good bios dump or modifying the bios downloaded from HP since Insyde H2O BIOS are a bit tricky. try googl*