HP EliteBook 8760w - No CPU VCore

[Johndill]

Hi, I've got a HP EliteBook 8760w with no CPU VCore, L6, L7, L8 all have no Vcore voltage. VCCSA is present. What should I check next? thanks

[piernov]

Re: HP EliteBook 8760w - No CPU VCore

Check enable signal on U1010 pin 7.

[Johndill]

Re: HP EliteBook 8760w - No CPU VCore

Check enable signal on U1010 pin 7.

If I counted right, U1010 pin 7 is 0.0mV

[Francisco.s]

Re: HP EliteBook 8760w - No CPU VCore

If I counted right, U1010 pin 7 is 0.0mV

Then check PWR_GOOD_3. Pin 4 U1012 should be 3 volts.

[Johndill]

Re: HP EliteBook 8760w - No CPU VCore

Then check PWR_GOOD_3. Pin 4 U1012 should be 3 volts.

According to the data sheet for pin arrangement, U1012
pin 1 is 3.3V
pin 2 is 1.4mV
pin 3 is 0.0mV
pin 4 is 0.0mV
pin 5 is 3.3V

[Johndill]

Re: HP EliteBook 8760w - No CPU VCore

Bump

[Johndill]

Re: HP EliteBook 8760w - No CPU VCore

What should I check next?

[piernov]

Re: HP EliteBook 8760w - No CPU VCore

Apparently PGOOD_MXM is needed for PWR_GOOD_3 to go high and get the CPU power regulator to turn on. PGOOD_MXM comes from the MXM connector apparently, and has a pull-up resistor to +V3S.
Is there a graphics card plugged in in the MXM connector? If there is, remove it, it may be pulling down the line (for an unknown reason right now).

[Johndill]

Re: HP EliteBook 8760w - No CPU VCore

Apparently PGOOD_MXM is needed for PWR_GOOD_3 to go high and get the CPU power regulator to turn on. PGOOD_MXM comes from the MXM connector apparently, and has a pull-up resistor to +V3S.
Is there a graphics card plugged in in the MXM connector? If there is, remove it, it may be pulling down the line (for an unknown reason right now).

Yes the MXM GPU was connected, I'll check again without it

[Johndill]

Re: HP EliteBook 8760w - No CPU VCore

Apparently PGOOD_MXM is needed for PWR_GOOD_3 to go high and get the CPU power regulator to turn on. PGOOD_MXM comes from the MXM connector apparently, and has a pull-up resistor to +V3S.
Is there a graphics card plugged in in the MXM connector? If there is, remove it, it may be pulling down the line (for an unknown reason right now).

With MXM GPU in, L6, L7 and L8 are 0.0mV, cold CPU.

With MXM GPU removed, L6, L7 and L8 are open line, hot CPU, PWR_GOOD_3 pin 4 U1012 is 3.3 volts.

[piernov]

Re: HP EliteBook 8760w - No CPU VCore

Is the computer booting without the MXM graphics card? Try to see if there is any HDD activity, any sound coming out from the speakers, if caps lock/num lock trigger the associated LED.

This MXM graphics card seems to be pulling down the PWRGD line so try with another graphics card if you have one.

[Johndill]

Re: HP EliteBook 8760w - No CPU VCore

Is the computer booting without the MXM graphics card? Try to see if there is any HDD activity, any sound coming out from the speakers, if caps lock/num lock trigger the associated LED.

This MXM graphics card seems to be pulling down the PWRGD line so try with another graphics card if you have one.

If I remember correctly, the caps lock was flashing 5 times with the GPU in.

The caps lock stays solid lit without the GPU connected so would it be right to say the motherboard is fine and the issue would be with the GPU?

I have a GTX 675M in my Alienware but don't really want to take it out :-)

[piernov]

Re: HP EliteBook 8760w - No CPU VCore

Check if you can turn off/on the caps lock light. Put an hard drive with an operating system and check if it's being read. (you should hear the heads moving at least)

You'd have to try with another graphics card to make sure it is indeed the issue.

[Johndill]

Re: HP EliteBook 8760w - No CPU VCore

Check if you can turn off/on the caps lock light. Put an hard drive with an operating system and check if it's being read. (you should hear the heads moving at least)

You'd have to try with another graphics card to make sure it is indeed the issue.

Thank you in advance for your help :-)

The caps lock was solid lit and did not turn off when pressed.

I'll clean it out and reassemble it for easier testing of your suggestions and replay back some time soon when I have completed your tests and maybe bear it and try out the GTX 675M from my Alienware as it's the only working MXM card I have and unfortunately HP didn't enable the intel integrated GPU on this board.

[Johndill]

Re: HP EliteBook 8760w - No CPU VCore

Check if you can turn off/on the caps lock light. Put an hard drive with an operating system and check if it's being read. (you should hear the heads moving at least)

You'd have to try with another graphics card to make sure it is indeed the issue.

Problem solved! I put my Alienware GTX 675M in it and it now boots and displays, is there a way of troubleshooting the MXM card or could I heat it up with a hot air reflow station and see of that will work?

[piernov]

Re: HP EliteBook 8760w - No CPU VCore

Great!
Could you take pictures of the dead MXM card?

[Johndill]

Re: HP EliteBook 8760w - No CPU VCore

Great!
Could you take pictures of the dead MXM card?

It's a Quadro 3000M

[caspian]

Re: HP EliteBook 8760w - No CPU VCore

MXM graphics cards has 3 different versions which are probably not compatible. In addition, if you buy a MXM card, it can not be trusted. Thus, finding and buying a compatible MXM card takes time.
to test the old card, first check whether the tantalum capacitors or the coils are shorted or not. but probably, the gpu chip should be failed.

[SMDFlea]

Re: HP EliteBook 8760w - No CPU VCore

Its MXM3.0b . http://forum.notebookreview.com/thre...581056/page-72

[Johndill]

Re: HP EliteBook 8760w - No CPU VCore

Its MXM3.0b . http://forum.notebookreview.com/thre...581056/page-72

Thanks, it looks like regular GTX cards will work with driver mods