Acer Aspire one 255 Compal LA-6221P PAV70 Rev1.0 not booting

Hello again,
The help I need this time is about AOD255 motherboard Compal 6621P PAV70.

I just got this laptop of a friend and its not booting. Pushing the power button connected to adapter/ battery lit the LED1 for about 5-6 seconds then it goes off again. The LED beside the power button don't turn on. If adapter inserted while battery installed the battery led lit blue, indicating charging??

No burned or blown parts seen during inspection with a magnifying glass. Reprogrammed the bios chip off board but still the same. There is 3V and 5V on TPS51125( checked at PL3 and PL4 ). Checked the coils resistance in ref to ground and I get around 230-644 ohms except for the PL5 i'm getting around 1200 K-ohms. Tested PL5 off board and I get 0.1-0.2 ohms. Any help will be appreciated in trouble shooting.

Measure the voltages on pins 23, 8, 17, 3 PU4

Machine napisał(a):Measure the voltages on pins 23, 8, 17, 3 PU4

PU4
Pin3=2V
Pin7=3.3V
Pin17=5.2V
Pin23=4.7V

Measure the voltages on PL6, PL7, PL8, PL10

Machine napisał(a):Measure the voltages on PL6, PL7, PL8, PL10

PL6, PL8, PL10 = 0.00V
PL7= 0.3V.

The strange part here is that the intel chipset is getting really warm, it wasn't so first I got the mobo. I did testing with careful ESD protection. Problem origin from chipset??

I asked the friend of mine if he did something with the board. He actually did reflow chipset with hot air gun. This info is new for me but I thought I share anyway coz it might be so that the mobo is beyond reparation??

Heating chipset might be a matter of bad reflow with possible joined connection but everything else is also possible. Howerev the mobo still have the same reading as first post.

You should check that fuel the tensions TIGERPOINT_ES1_BGA360
Measure the voltages on all the pins of Q19, Q27, Q15, PQ1, PQ3.

Machine napisał(a):You should check that fuel the tensions TIGERPOINT_ES1_BGA360
Measure the voltages on all the pins of Q19, Q27, Q15, PQ1, PQ3.

Q19
S= 1.4v D= 5.2v G= 0v
Q15
S= 2.5v D= 3.3v G= 0v
Q27
S= 0v D= 0v G= 0v
PQ1
S= 18.15v D= 18.15v G= 3.22v
PQ3
S= 18.4v D= 18.4v G= 3.2v

1.8v missing?

voltages on Q19, Q27, Q15

Voltages measured at start-up?
Measure the voltages on all the pins of Q14, PQ32
Voltage pin 32 U6 (KBC) at power OFF
down with power ON
Power ON released
1.8v is normal that there is not at this stage

Machine napisał(a):

voltages on Q19, Q27, Q15

Voltages measured at start-up?
Measure the voltages on all the pins of Q14, PQ32
Voltage pin 32 U6 (KBC) at power OFF
down with power ON
Power ON released
1.8v is normal that there is not at this stage

PQ32
D= 3.3V S= 0V G=0v

Q15
1=0v
2=0v
3=4.7v
4=0v
5=0v
6=4.7v

As for U6 its 14 pin qfn chip.
Is it PU12 u ment
if so then pin 32 is 0v pwroff, on down and released.

Measure the voltage (see picture) ON / OFF #
to power off
with pover on hold
with power on released

Machine napisał(a):Measure the voltage (see picture) ON / OFF #
to power off
with pover on hold
with power on released

Sorry for taking too long, I was away.

D14 ON/OFF#
pwroff 3.03v
pwron hold 0.43v
pwron released 3.03v
pushing pwron once ( not hold ) 1.49v

Measure the voltages on pins 14, 6, 110 of U6 KBC (no PU6)

Machine napisał(a):Measure the voltages on pins 14, 6, 110 of U6 KBC (no PU6)

U6
pin6 pwroff = 0.04, pwron = 0.43v
pin14 pwroff = 0.01, pwron = 0.01v
pin110 pwroff = 0.11, pwron = 0.12v

No communication with the bridge.
Try with another bios
Make a reflow of the bridge and replace if necessary.

Any idea which bios file I should program
PAV70D2.fd
or
PAV70D3.fd

Last time I tried with the D3, all bios files comes with these two versions.

I will try with all versions available then if its the same I'll order a new bridge or reball the existing one.

I'm not an expert in bios.
Try them both.
Save bios on the card before replacing it (backup)

montarbo napisał(a):Any idea which bios file I should program
PAV70D2.fd
or
PAV70D3.fd

Last time I tried with the D3, all bios files comes with these two versions.

I will try with all versions available then if its the same I'll order a new bridge or reball the existing one.

It depends on the version of the mainboard. DDR2 memory version - PAV70D2, DDR3 memory version - PAV70D3.

Machine napisał(a):I'm not an expert in bios.
Try them both.
Save bios on the card before replacing it (backup)

Tried 4 bios versions with each 2D and 3D, meaning 8 bios files nothing changed. Now the bridge I already off board, cleaned and ordered new one from eBay. Ordered also stencil for the cg82nm10, will try re-balling the original one, if not working will try the new one when arrived, these orders might take up to 3 weeks to be delivered to Sweden, will get back to you when done. Thanks a lot for every help and trouble shooting.

BR

Finally got new bridge from eBay, replaced the old one.
New bios flashed.
Board is working, tested for about 5 hours without problem.