Dell Alienware r3 17 i7 dead board

[kuba2102]

Hi. I have problem with the aforementioned laptop. I replaced the KBC as I found the short on it, with new one short was gone, but I get no voltages across the board apart from 19V on main rail and 3.3V on power button. I definitely need a help to move on. Thanks

[mon2]

Re: Dell Alienware r3 17 i7 dead board

Post or link the schematic and boardview files if on this forum.

Start with locating the power adapter connector. This will be near the usual dcin mosfets and the charger IC.

What are the markings on the charger IC? You can post pix of the part.

Review the voltages on the dcin mosfets (source, gate,drain).

Often these mosfets blow but we can check by reviewing their resistance. Start with the voltage check first.

Resistance checks are always with the power off.

[kuba2102]

Re: Dell Alienware r3 17 i7 dead board

I am using Dell AAP11 AAP21 LA-C912P rev 1.0 although my board is rev 2.0, and boardview LA-C912P Echo15MLK_0723B_NV.cad

My question is, if the KBC is removed, should 3VALW and 5VALW be present anyway or KBC does enable it? PU100 TPS51225CRUKR have 5V and 3V have enable
pin that goes straight to the KBC so I presume it's the KBC that has to enable it first? thanks

[mon2]

Re: Dell Alienware r3 17 i7 dead board

It is possible that the regulator has an internal pull up and then the default floating state will be to enable the regulator. If KBC drives the pin low, regulator will then be OFF. This case is for active HIGH enable.

Reverse case for an active LOW enable.

[kuba2102]

Re: Dell Alienware r3 17 i7 dead board

Hi. I had to get a new KBC chip and I managed to get the voltages and somehow program the new KBC, BUT it programs itself only up to 00010000 address, which is something like 8MB instead of 16MB code. Im using SVOD4 and have no idea what could be causing it.