Asus Chromebox CN62 - wrong chip put on BIOS reader

[BMCappelletti]

Long story short:
- dad converted Asus Chromebox CN62 into Windows compatible, with mrchromebox BIOS, years and years ago
- gave the computer to his son a couple years later
- son now decided to revert it to Chrome OS, to sell it as original (re-writing BIOS with the backup one created by his dad)
- too lazy to remove the board from the case, thought a voltage regulator was the BIOS chip (you know... it has 8 legs)
(seems like the story was not that short)

He used alligator clips to read the chip. No luck reading it. Removed chip and placed on a SOC-8 adapter. When the software said nothing was on it for the second time, he noticed something was wrong.
Soldered the chip back and... no power. PC was not turning on.

And now it's here with me.

So, I'm attaching a boardview to this thread. Could not find schematic. https://www.badcaps.net/forum/troubl...ebox-boardview

He removed PU2 component and placed on the BIOS reader. PU2 seems to be a G9661-25 chip.
https://www.alldatasheet.net/datashe...1-25ADJF6.html
BIOS chip is U18, which is a 25Q64FV chip.
https://www.alldatasheetpt.com/datas...5Q64FVSIG.html

I see pin 8 on BIOS chips are VCC. But pin 8 on that voltage regulator is ground. Could that have burned the chip?
Even if the chip was not damaged, I decided to get a new one and replace it. But still the board is kind of dead.
What other issues that alligator clip could have caused to the board, considering it may have added voltage to places it should not? (even though VCC on the writer would send 3.3V to ground)
When connected to a power supply, at first the coils do not have voltage. When pressing power, the voltage regulator has 3.3V on PIN 3 and 5V on PIN 4. PIN 2 (VEN) is missing. I have 3,3V on the coil PL1, 1V on coil PL4 and 5V on coil PL5. Coils PL2 and PL3 are open line. PC draws 8mA from the power supply when connected. No change when power is pressed.

I did re-write the correct BIOS chip with the backup file. No luck.

Regarding the missing VEN, it goes to a couple resistors and a cap beside the voltage regulator. One resistor and a cap have GND on the other end. The other resistor MAINON_L on the other side and goes to PR42. But I don't have that PR on the board. Only a test point. And nothing on there. So I'm stuck at this point.


Any clue?
Thanx.

[reformatt]

I'd expect to see 0ma draw before power button is pressed, so that current must be going somewhere. Thermal camera helps in these cases. First suspect for me would be the EC, then the PCH given the fuckery with the board.

Measure each coil resistance to ground. CPU coils will read very low, but PCH should be 100 ohms or more. MAINON_L would come from the EC (U20)

[BMCappelletti]

I'd expect to see 0ma draw before power button is pressed, so that current must be going somewhere. Thermal camera helps in these cases. First suspect for me would be the EC, then the PCH given the fuckery with the board.

Measure each coil resistance to ground. CPU coils will read very low, but PCH should be 100 ohms or more. MAINON_L would come from the EC (U20)

All coils have a high resistance or are open line, except for PL2, which is 36ohms.

[BMCappelletti]

I'd expect to see 0ma draw before power button is pressed, so that current must be going somewhere. Thermal camera helps in these cases. First suspect for me would be the EC, then the PCH given the fuckery with the board.

Measure each coil resistance to ground. CPU coils will read very low, but PCH should be 100 ohms or more. MAINON_L would come from the EC (U20)

As for heat, the only thing that seems to get any hot (and not much) is PU3.
The readings on its pins are:
1 - 19V
2 - 0
3 - 0
4 - 3.3V
5 - 1.7V
6 - 3.4V
7 - 3.4V
8 - 3.4V
9 - 3.4V
10 - 8.5V
11 - 5.1V
12 - 8.5V
13 - 3.3V
14 - 0
15 - probably same as 8 and 9
16 - probably same as 8 and 9