Technical Support Laptop won't power on, standby light stays on

[bledarh]

Hi,

the laptop motherboard originally had problems with the cooling fan, something like: "System has detected a not properly working cooling fan". I opened the motherboard to reset the bios (removing the RTC battery, and shorting the pins). After plugging power, it does not power on. The standby light stays on. I put the motherboard on the power supply and it is drawing no amps at all.
Has anybody encountered this situation before?
Motherboard model : LA-B181P Rev. 1.0
Thank you.

 

[Patrick Ribbsaeter]

Hi,

the laptop motherboard originally had problems with the cooling fan, something like: "System has detected a not properly working cooling fan". I opened the motherboard to reset the bios (removing the RTC battery, and shorting the pins). After plugging power, it does not power on. The standby light stays on. I put the motherboard on the power supply and it is drawing no amps at all.
Has anybody encountered this situation before?
Motherboard model : LA-B181P Rev. 1.0
Thank you.

Shorting the pins?--- What did u short? You might have shorted the motherboard by doing so... Have u done any other measurements, check standby circuit? current sense resistor?

 

[bledarh]

Shorting the pins?--- What did u short? You might have shorted the motherboard by doing so... Have u done any other measurements, check standby circuit? current sense resistor?

I shorted them without charger plugged in and without the RTC battery in.

 

[Patrick Ribbsaeter]

What other measurements did you do?

When resetting rtc battery. u don't need to short anything. Just take out RTC battery and press start button for a few seconds, that will drain the computer of electricity and reset bios. But that's not the issue now.. You need to post some voltages for us to know more ?

 

[bledarh]

What other measurements did you do?

When resetting rtc battery. u don't need to short anything. Just take out RTC battery and press start button for a few seconds, that will drain the computer of electricity and reset bios. But that's not the issue now.. You need to post some voltages for us to know more ?

19v ,3,3 (it is 3.5v actually), and the 5v all are there. But it won't turn on.

 

[Patrick Ribbsaeter]

19v ,3,3 (it is 3.5v actually), and the 5v all are there. But it won't turn on.

3v, and 5 v its not all are there.. many more things before it powers on.. what else do you have so far, post more info?
Ram voltage
Pch voltage
Cpu voltage
etc etc etc.. bios voltages, did u check all pins? Data, SCL lines... clock frequencies?
Did u check for short?

 

[bledarh]

bios voltages, did u check

3v, and 5 v its not all are there.. many more things before it powers on.. what else do you have so far, post more info?
Ram voltage
Pch voltage
Cpu voltage
etc etc etc.. bios voltages, did u check all pins? Data, SCL lines... clock frequencies?
Did u check for short?

Thank you sir for replying and trying to help me. I am not so knowledgeable in motherboard repair. This is all I can do, what I have already described above. I though maybe someone else has encountered the same symptoms and could give me a "ready" solution.

 

[Patrick Ribbsaeter]

Thank you sir for replying and trying to help me. I am not so knowledgeable in motherboard repair. This is all I can do, what I have already described above. I though maybe someone else has encountered the same symptoms and could give me a "ready" solution.

Thats ok, we are all beginners at some point.
Check Bios all 8 pins..
Pin 1 3.3v
Pin 8 3v3
Also check Pin 7, Pin 2, Pin 6,. Pin 5
You need oscilloscope, u have?

I also recommend, you watch ALL Dr bios videos. before starting Watch every video... Will give u better understanding of laptop repairing and make notes.

 

[bledarh]

Thats ok, we are all beginners at some point.
Check Bios all 8 pins..
Pin 1 3.3v
Pin 8 3v3
Also check Pin 7, Pin 2, Pin 6,. Pin 5
You need oscilloscope, u have?

I have checked pin number 8 and it showed 3.3 volt. I don't have oscilloscope to check the signals you mentioned.

 

[Patrick Ribbsaeter]

I have checked pin number 8 and it showed 3.3 volt. I don't have oscilloscope to check the signals you mentioned.

You need to invest in one.. It pays it back with time.. from repairs..
Do you have SLP_5, SLP_S4, SLP_3?
Did u check requirement for SMC, PWR_BT? SMC_RST?
Post(take measurements) voltages from all the Inductors for CPU,PCH, Ram etc...
Do you have VCCSUS 3_3_S5 and S5_PWRGD?

 

[Hosein Asadolahi]

I have checked pin number 8 and it showed 3.3 volt. I don't have oscilloscope to check the signals you mentioned.

I suggest upgrading your electronic knowledge first, instead of looking for specific solutions for each device that are also difficult to find.
Our goal was for you to learn to fishing instead of giving you a fish .
if you watch some video you know how to check the laptop voltage .
i cant repair your laptop from here without any good information .

 

[bledarh]

Thank you all for your support. I will try to increase my knowledge.