There is Hp 625 Valima. No Clock on Bios Pins(6th pin, 2th pin, 5th pin). so I track 6th from Schematic and saw it connected to IO(SMSC KBC1098). So I changed It by new one, But no changes, We have 3.3 on PWRSW and goes down when press it. Check PWRSW on SMSC so it is OK as switch. What can I do? Why SMSC not produces the KBC_SPI_CLOCK?

№1 - check power to vcc1, vcc2
№2 - check clock to 70-71 pins ( 32768 Hz)
№3 - flash bios...

VCC1 exist 3.3 V on all pins, VCC2 expect to produced after power on,
So frequency on 70-71th pin is True(checked by oscilloscope).
But no frequency on KBC_SPI_CLK.

remove SPI FLASH & check to 6, 5 , 2 pins
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look to http://www.vlab.su/viewtopic.php?p=62203#p62203

Bios IC picked Up, so something changed(Amber LED blinking), I realized that BIOS must be read on start up. SO By focusing on Plug in time, CLK and SI, SO frequency observed, I it is interesting, Just on plug in time clock produced and SPI Flash read from KBC. But no power again. BIOS id true, KBC changed, SB changed, no reaction to PWRSW.

OH, Clock was produced just a moment when you plug in!! in that time( less than a second) data read from bios. by changing U516(tps51117) now power on but no display!! now we have no LPC activity, IO & SB is true but no LPC.