Acer Aspire 5100 - Compal LA-3121P wont start

[rtstorm]

Hi, i have this laptop that wont start(no fan, no LED). I check all from power jack to power supply IC (MAX) where i have 3v and 5v output. I noticed i do not have +CPU_CORE from PU11(page 48). The ic wont send signal to G of MOSFET to open. Is this fail of MAX8774GTL+ IC?

From where this IC get logic 1 to send signal to G of MOSFET?

[atsio]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

You need 5v on pins 19, 37, 25,vid signals (variable voltage depending on cpu type), 3v on pin 17 and VR_ON signal.

[rtstorm]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

Pin 19 = 0.20V
Pin 37 = 0.40V
Pin 25 = 0.40V

Pin 17 = 0.55V

[atsio]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

What is the voltage on the pins of U7 and U41?

[rtstorm]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

U7:
D - 5.2v
s - 0.2v
g - 0v

u41
d - 3.3v
s - 0.14v
g - 0v

[atsio]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

Check voltage on pins of PQ22 and PQ23

[rtstorm]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

PQ22:
pin 1 - 3.3V
pin 2 - 18.8V
pin 3 - 18.8V

PQ23:
pin 1 - 5V
pin 2 - 0V
pin 3 - 0V

[atsio]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

What is the voltage on pins of U3?

[rtstorm]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

U3:
D - 1.8v
s - 0v
g - 0v

[atsio]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

Sorry for not answering earlier but I was too busy.
Check voltages on pins 148, 149, 176 and 30 of U27 (KBC)

[rtstorm]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

U27:
pin 148 = 0V
pin 149 = 0V
pin 176 = 0.15V
pin 30= 3.3V

you do not apologize, thank you for helping me

[drdyzio]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

im interested in this thread got a similar netbook acer one 250 that has no power. hope we can fix this.

[atsio]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

Although you have S3 enable signal, KBC will not post SYSON and SUSP# signals. That points to a problem with KBC. Have you flashed the bios?

[rtstorm]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

now when i take a look at the bios IC (U17) i see that someone has change it. Marking on the IC is 'MX M070918' and the schematic say it shoud be 'SST 39VF080'. I se that it has beed soldered.

Now if i buy SST 39VF080 i do not have TSOP 40 adapter from my TL866 promramator.

[alihomee]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

pics of mobo may helpfull

[rtstorm]

Re: Acer Aspire 5100 - Compal LA-3121P wont start

Here it is