hi guys
happy new year

there is a board that southbridg of it was so hot when connect the power
i change the southbridge

but now in turned on,but no display
it use 0.7 amper
i program the bios&EC

whats your view؟

i think there is again southbridge problem. might be southbridge is not placed right. you have to replace or reball it.

southbridge replaced

Not make a difference

How much amps take when u plug jack in, and how much when power on?

Check the PCH start sequence, if you find the Plataform reset signal (PLTRST#)is highly possible that the PCH works fine, if not, check the PCH start sequence backwards to try to find the problem.

All the power supplies are ok ? The system clocks are ok ?

Good Luck

how i should check this signals?
i dont have oscilloscope

whenturn it on PLTRST#=3.3V

Check in power on sequence witch one signal is not present,
If u don't have osciloscope check voltages on quartzs, better than nothing.
What about voltages on coils? all ok?

Topicstarter, an oscilloscope is highly recommended in such cases, try to find it. Are you sure your CPU is good? These CPUs are known for their frequent fails. Also install 100% working RAM module. Can you tell us pre-failure conditions of your laptop?

I'm advicing you to see is there any activity on BIOS flash pin 2 and LPC LAD0. Does BIOS you've flashed contains ME region? However, are there any hot chips? EC, LAN...