eMachines M5116 laptop - no CPU CORE voltage...

[HandyMan]

Hi,

Maybe there are some engineers on here who carry out laptop repairs?

I am trying to repair an eMachine M5116 laptop - http://www.theregister.com/2004/04/19/emachines_m5116_review/ - but although I have mended several laptops in the past, this one is proving difficult.

When turned on, the LED lights up beneath the 'on' button but nothing else happens. I have discovered that there is no CPU CORE voltage being fed to the CPU. When it's turned on, the PWM controller (ISL6215CA) and PWM drivers (2 of ISL6207) all receive their 5V VCC feeds to the correct pins, but the 4 MOSFETS (2 upper and 2 lower) they drive are not being switched on. My 'scope is showing no PWM drive being sent to the PWM input pin on the ISL6207 drivers, although there is DC of 2.8V present on those lines. Other than that, I cannot find anything wrong, so I am assuming the ISL7215CA controller IC is defective. I can only find the datasheet for the ISL7219CA controller, but this appears to be identical in form and operation, should anyone wish for the URL of the datasheet.

Anyone have any ideas on whether the controller may be faulty, or if I should be looking elsewhere?

I can't understand why the controller is being powered but not running the driver ICs which in turn are not running the MOSFETs, but it's difficult when the controller IC uses so many feedback and control lines...

Many thanks,
James

[bsaints]

Hi,

I was just wondering if you fixed that laptop. I've got the same model and (I think) the same problem. When power supply is connected (power switch is not pressed) the green light comes on and nothing else happens, after a while cpu fan spins up and the cpu is hot, nothing happens when you press the power button.

Thanks a lot.
Thomas