Pavillion DV7 DAUT1AMB6D0 REV:D


Hi,
I have 2 motherboards with the same behaviour, both load the operating system and have windows welcome sound, but can't see the image.

First thing I did was program bios chip with a known good dump.

One of them came at first with no boot problems and leds blinking, but after heating the northbridge softly, motherboard return to live.

I have change the northbridge, and now boots windows, but as explained above.

All voltages are good apparently, but northbridge has a few capacitors over its body that are short circuited. (zero ohms in the lowest ohms multimeter scale) (I think all of them are from +1.8V_VDDLT_18_NB supply)

The other motherboard has the same capacitors short circuited, but if heat the northbridge, then it boots normal and has a clear image on its lcd screen. (after removed the fan assembly, the capacitors are still short circuited)

I wonder if it is normal this behaviour of northbridge, but I have another similar motherboard, but UMA type with the same AMD northbridge chip , and over the same capacitors the readings are 883 ohms.

Need some advice in order to fix this motherboards.

Anyone faced a similar problem?

It's normal.

Could you explain it a little?

Do you say that capacitors are short-circuited because there is some part damaged?
Or it is made this way by manufacturer, because this part of circuit is not in use? (I know that in the UMA motherboard it is in use, because it receives 1.8 volts.

Thanks for your answer.

(for non-UMA)

I would like a better explanation,.

Anyone has a better answer, I mean more extensive, if it is possible.

Thanks.

If you remove northbridge, you will see,that this capistor not short circuted on it. Short circut on pcb, because this part of circuit is not in use.