[help]ASUS K40C REV 2.1 DEAD

[phantomEVO]

Hi to all! please help me! i'm a newbie

motherboard k40c rev 2.1

i've voltage on bios, on power button, and battery connector but when i push the power button nothing happens: no amps abdsorbed by power supply

can you help me thanks!

p.s i've tried also to reflash the bios

[Techtiger]

Re: [help]ASUS K40C REV 2.1 DEAD

What are the voltage you have examples +3/5V ?

[phantomEVO]

Re: [help]ASUS K40C REV 2.1 DEAD

thank you for your reply! I confirm i have +3,3va and +5va

[Techtiger]

Re: [help]ASUS K40C REV 2.1 DEAD

thank you for your reply! I confirm i have +3,3va and +5va

Ok your buck regulator +3/5V IC out put a Power good single test if you have this & find out the Bordview what is your EC ? Number

[phantomEVO]

Re: [help]ASUS K40C REV 2.1 DEAD

i've the board view and the schematic, but i don't understand what you want that i check

could you explain me better (sorry)

could be IT8500e?

[Techtiger]

Re: [help]ASUS K40C REV 2.1 DEAD

i've the board view and the schematic, but i don't understand what you want that i check

could you explain me better (sorry)

could be IT8500e?

Post the schematic and the bord view

[phantomEVO]

Re: [help]ASUS K40C REV 2.1 DEAD

schematic and boarview....

using thermal camera, i've seen that as soon as i connect the power supply, u8101 (RT8206B) become hot, but i've checked all pins and i have not shorts

[Techtiger]

Re: [help]ASUS K40C REV 2.1 DEAD

U8101 is the buck contrôler it became hot or very hot ? What is the voltage on pin 13 28? u3001 pin 112 voltage as you presse the power btwn ? resistance on all coils examples L8102 /L8101 ?

[phantomEVO]

Re: [help]ASUS K40C REV 2.1 DEAD

pin 13 of u8101 0,7
pin 28 of u8101 0v
pin 112 0v

resistence 1ohm (black probe on a side of the coil, red on the other side)

[Techtiger]

Re: [help]ASUS K40C REV 2.1 DEAD

résistance 1 ohms L8102 or L8101? No supply no this coils ?

[phantomEVO]

Re: [help]ASUS K40C REV 2.1 DEAD

no voltage at all

[Techtiger]

Re: [help]ASUS K40C REV 2.1 DEAD

résistance 1 ohms L8102 or L8101? No supply no this coils ?

Put the multimetre continuité mode and test L8102 L8101 note down the mesurent
Q8101 Q8102 Q8103 Q8104 make sure these mosfets are not short
U8101 pin 1 2 3 4 6 7 8 14 19 20 supply ?

[phantomEVO]

Re: [help]ASUS K40C REV 2.1 DEAD

l8101 and 02 beeps (1ohm)
voltage of u8101

1=2v
2=2v
3=4,98
4=5,11
6=19,32
7=4,98
8=0
14=3,2
19=5
20=0

about mosfet: i don't know how to test it, but i've write on the picutre, voltage that i've measured

[Techtiger]

Re: [help]ASUS K40C REV 2.1 DEAD

l8101 and 02 beeps (1ohm)
voltage of u8101

1=2v
2=2v
3=4,98
4=5,11
6=19,32
7=4,98
8=0
14=3,2
19=5
20=0

about mosfet: i don't know how to test it, but i've write on the picutre, voltage that i've measured

ok there is short in +5VSUS line to find out what side is short you have jumper JP8103 you have to remove it, for do it remove the solder from the jumper isolated both side test again what side is short (multimetre continuité mode test both side and the note the value )

what is the value L8102 multimetre continuité mode ?
to test mosfets (https://www.youtube.com/watch?v=-0WjwVDtBR0)

can you uplode pic from using thermal camera

[phantomEVO]

Re: [help]ASUS K40C REV 2.1 DEAD

it's not shorted!

in fact i have +5v on the pin of u8101 directly connected to the jumper!

i have short on pin 11 but i think it's normal

when you ask me to check l8102 and 01, you mean with a probe to ground? In this case, they don't beep.

P.s eveni u8102 become hot (hot only with camera..impossible to see with alcol or rosin)

when i power on the psu, it absorb 0.006 amp with u8101 and u8102 hot.

if i remove u8102, i have no amp from psu and u8101 don't become hot. but on u8102 i have right voltages

[Techtiger]

Re: [help]ASUS K40C REV 2.1 DEAD

it's not shorted!

in fact i have +5v on the pin of u8101 directly connected to the jumper!

i have short on pin 11 but i think it's normal

when you ask me to check l8102 and 01, you mean with a probe to ground? In this case, they don't beep.

P.s eveni u8102 become hot (hot only with camera..impossible to see with alcol or rosin)

when i power on the psu, it absorb 0.006 amp with u8101 and u8102 hot.

if i remove u8102, i have no amp from psu and u8101 don't become hot. but on u8102 i have right voltages

Remove U8102 and test impedance of pin 1 3 4 5
Put the multimetre continuité mode and test L8102 L8101 In the multimeter screen you will get a value forget the beeping or put it on Ohms

[phantomEVO]

Re: [help]ASUS K40C REV 2.1 DEAD

continuity mode with a probe on ground and a probe on one side of l8101 and l8102?

and what about impedence? what do you mean?

[Techtiger]

Re: [help]ASUS K40C REV 2.1 DEAD

continuity mode with a probe on ground and a probe on one side of l8101 and l8102?



and what about impedence? what do you mean?

yes that's correct and for impedence is ohms

[phantomEVO]

Re: [help]ASUS K40C REV 2.1 DEAD

in continuity mode, one probe on ground one probe on l8101 or l8102 i 'have OL.

if i put in kohm scale, i have

l8101 25kohm on both side
l8102 35kohm on both side

if i put the two probe on l8101 or l8102 in continuity mode, i have 1,1ohm

BLACK PROBE ON GROUND

pin1 200kohm
pin3 200kohm
pin4 10kohm
pin5 26kohm

[phantomEVO]

Re: [help]ASUS K40C REV 2.1 DEAD

i don't know if i can measure anything else...i'm disperate...