Quanta HK1 , no video lcd, vga or hdmi.

[Francisco.s]

Hi, have a laptop Sony with mbx-247 (Quanta HK1) motherboard, with no video on lcd nor external connectors.

It boots ok from hdd or usb and all voltages seems to be good.

There are no EDIDCLK and no EDIDDAT, so I think is a pch or gpu related issue.

The gpu or pch doesn't respond to heat.

A new bios dump didn't solve the problem either.

Any advice before replace pch or gpu?

Thanks.

[emestee]

Re: Quanta HK1 , no video lcd, vga or hdmi.

Test resistances on every LVDS pair.

[Francisco.s]

Re: Quanta HK1 , no video lcd, vga or hdmi.

Hi, I have done test resistance between each pair of lvds video signals, and all are 99.8 ohms.

Diode mode readings of those signals to ground are .499 in all of them.

Seems good for me.

Diode mode readings for EDIDCLK and EDIDDAT are also good.

Thanks for your advice.

[emestee]

Re: Quanta HK1 , no video lcd, vga or hdmi.

Well, EDID lines should be tested with an oscilloscope for signs of life. I'd look at the block schematic of the board to see how both external and internal video is routed, and then make sure there isn't some common circuit before the GPU/PCH that may be the source of the problem. Of course, throwing in a diagnostic card wouldn't hurt.

[emestee]

Re: Quanta HK1 , no video lcd, vga or hdmi.

Oh yeah, looking at the GPU oscillator generation would be a good idea too.

[Francisco.s]

Re: Quanta HK1 , no video lcd, vga or hdmi.

Well, EDID lines should be tested with an oscilloscope for signs of life. I'd look at the block schematic of the board to see how both external and internal video is routed, and then make sure there isn't some common circuit before the GPU/PCH that may be the source of the problem. Of course, throwing in a diagnostic card wouldn't hurt.

Yes, EDID lines have a 3v dc voltage reading, but no pulses at all.

There is good 27Mhz oscilating signal at the resonator pins of gpu oscilator circuit.

Do you know if boardview for this board is avaible?

[SMDFlea]

Re: Quanta HK1 , no video lcd, vga or hdmi.

Measure the voltage on KU1 pin 21,and U1 pin 1 and 3

[Francisco.s]

Re: Quanta HK1 , no video lcd, vga or hdmi.

Measure the voltage on KU1 pin 21,and U1 pin 1 and 3

Hi, this are the readings:

U1

Pin 1 LCDVCC no volts
Pin 3 no volts
pin 4 and 6: 3,3 volts

KU1 pin 21: 3,3 volts

[SMDFlea]

Re: Quanta HK1 , no video lcd, vga or hdmi.

Connect the screen and keyboard,try the fn keys for external HDMI and VGA . Did you flash the EC chip

[Francisco.s]

Re: Quanta HK1 , no video lcd, vga or hdmi.

I will try to flash the ec bios, it is something I hadn't thought.

Thanks, I will tell you if it solves the problem.

[Francisco.s]

Re: Quanta HK1 , no video lcd, vga or hdmi.

Did you flash the EC chip

Unfortunately this mobo has no a dedicated ec-bios chip. (KU3 is not mounted)

Most probably main bios has the data for pch bios and kbc.

Attached the original bios just in case could verify it.

Thanks.

[SMDFlea]

Re: Quanta HK1 , no video lcd, vga or hdmi.

You can try a known good bios but i don`t think it will make any difference - https://www.badcaps.net/forum/showthread.php?t=62366 .Is your EC a NPCE795L ,and what revision number is your board

[Francisco.s]

Re: Quanta HK1 , no video lcd, vga or hdmi.

It's a DAOHK1MB6E0 Rev.F, and EC is the NPCE795L.

I've found the signal NVIDIA_PEX_RST# is always at low level. ( diode mode in that signal is ok, no short)

In the other hand the PLTRST_DIS# is at high level as expected.

I'll try that bios and will make some more measurements, but NVIDIA_PEX_RST# signal makes me think that nvidia gpu is damaged.

Thanks for your help.

[SMDFlea]

Re: Quanta HK1 , no video lcd, vga or hdmi.

https://www.badcaps.net/forum/showthread.php?p=879649 post #86 . One of the members posted a power sequence but was unsure if its correct or not. You can try it anyway.

[Francisco.s]

Re: Quanta HK1 , no video lcd, vga or hdmi.

https://www.badcaps.net/forum/showthread.php?p=879649 post #86 . One of the members posted a power sequence but was unsure if its correct or not. You can try it anyway.

It is a good piece of information.

I've found the signal NVIDIA_PEX_RST# is always at low level

.

Other signal that seems to be wrong is FB_CMD20, it goes to all video ram chips and connected to RESET input of all chips, it has no voltage and presents no short to gnd.

Also tested DGPU_PRSNT# and it has 3 volts to enable discrete graphics.

I will continue with the tests but probably it's a waste of time.

If someone have any advice it will be welcome.

Thanks.

[Mr.D]

I have the same issue with Same MB
Did someone here have a solution for this problem ?
i already re-write the BIOS But it Still gives me F9 error code as before