HP 6715s won't turn on

[taby123]

I have an HP 6715s laptop. It won't turn on. When I press the power button yellow LED blink once and then turns off. I have taken it apart. I found that when I take out the audio board the laptop turns on but nothing on the screen. The fan spins. It has an ATI SB600 southbridge chipset. AMD Turion CPU. I have changed the audio board with a known good one. No luck. When I plug in the audio board laptop won't start at all. Southbridge chip handles the audio. Any idea how I can check if the southbridge or northbridge IC is faulty. I have ordered a new CPU. Will test when it arrives. Memory is good. Tried with a known good one. As soon as I plug in the audio board the laptop won't start. When I take out the audio board it starts again. But no display on screen. External screen no display as well. I am guessing northbridge or southbridge ic is gone. Battery is good. Charger is good. I have tried with battery and without battery.
Any help or suggestion will be highly appreciated.

Regards,
Taby

 

[desigabri]

hi
I have an HP 6715s opened for repairing.
I need an help and I could help you if you need. If you need I could send you some piece of the laptop for testing pourposes. I'm from Italy so because I don't know where you from, I don't know if it will be too much expensive to do. Anyway if you can measure some analogic parameters I could do the same with my board and send back to you the values.

I need some pictures of the board next to the power connector. The previus owner of the laptop broke some traks on the board trying to repair the power-on switch.
If you can't send to me a pictures I would like you tell me something about the tracks

thanks in advance

I can't add again the same pictures but you can find them at this other post:
https://www.techspot.com/vb/topic132607.html

 

[taby123]

Today I have changed the CPU with a new one. No luck. The problem remains the same. My laptop still does not turn.

 

[desigabri]

ehi taby could you take a picture of the power-on switch? I mean you take a picture of the board close to the power-on switch