notebook FAN is not spinning

[hackoff]

Hello masters,
i have problem with notebook of my friend. Her Fujitsu Siemens Amilo Pi 2550 is not working. I dont know what is cause and consequence. When i turn it on, it shows booting and F2 for BIOS menu and after that next step it shows only black screen with white cursor. It is not about bad booting. 1st is HDD , 2nd DVD ROM. but the main defect is i think that FAN is not working. it is not spinning when i turn that notebook on and when i let it turned on for a while it starts to overheat.
I also triend to chceck fan cable. it has 3 pins and when i tried to measure voltage there all 2 pins combinations (black, yellow, red) showing me 0V. So where could be problem?

 

[MoPCTech]

Hello masters,
i have problem with notebook of my friend. Her Fujitsu Siemens Amilo Pi 2550 is not working. I dont know what is cause and consequence. When i turn it on, it shows booting and F2 for BIOS menu and after that next step it shows only black screen with white cursor. It is not about bad booting. 1st is HDD , 2nd DVD ROM. but the main defect is i think that FAN is not working. it is not spinning when i turn that notebook on and when i let it turned on for a while it starts to overheat.
I also triend to chceck fan cable. it has 3 pins and when i tried to measure voltage there all 2 pins combinations (black, yellow, red) showing me 0V. So where could be problem?

It sounds like you have verified the issue. If you are recieving 0 vdc with the Red (+) and Black (-) when powered up it is most likely hitting thermal shutdown. If you have a battery of 6-12V you can test the fan and i repeat ONLY THE FAN by touching the black and red to the appropriate poles of that battery.

The yellow is the signal from the sensor. Also verify that there is nothing jamming the blades of the fan, dust, lint, a screw, etc... If you blow air through the heatsink make sure you hold the blades still so you dont spin a bearing or pump voltage through the MB.

DC motors will function as generators if you Blow air through them and they hit a high enough RPM.

 

[jarotech]

Hi, if you have no voltage on the connector CN17, the fan is not the problem, you need +5V between pins 3 and 1, and +3.3V between pins 2 and 1.

 

[hackoff]

ohh, thx for answers. i already cleaned the fan from all dust before i tried think about any other possibilities. you had very good idea about blowing into the fan so i generated about 0.5V with it so i think fan is ok. i dont have any battery to test it other way. maybe give some 1.5V batteries in paralelly but this was easier. as jarotech said i didnt have any voltage on pins during laptop was turned on. so what to do now?

 

[jarotech]

You can check the voltage on the R247 resistor, it's connected to the fan control, you should have 0 to 3.3V.

 

[hackoff]

i am afraid i cannot find R247 resistor. where is it located? at least aproximatelly

 

[jarotech]

I can't tell you because I'm working with a schematic, not the PCB itself. But to be sure, check if the chip U27 is a LM358. If it's the right one the R247 is connected to the pin #2 of that chip. So you can measure pin #2 if you have 3.3V.

 

[hackoff]

after an hour of searching i found R247 under a GPU board. I measured it and there was exact 3.3V DC. So signal to the fan is alright i suppose. So it means that it doesnt give any voltage to the fan. but what to do?

 

[jarotech]

Ok that is a good thing, it's not your embedded controller IT8512E your problem, check the voltage on the R252 resistor on both side. We are close to the problem.

 

[hackoff]

on R252 i see 1.67 V DC

 

[jarotech]

Also check the R347 resistor, on one pin you have the +3.3V, what do you have on the other one. Check the U27, what do you have on pins 1,2 and 3. Another one is the B111 coil, what voltage do you have. Give me all those voltages and I will examine the data.