Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Troubleshooting Laptops, Portable, and Mobile Devices
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 09-12-2018, 06:45 AM   #1
danea
Member
 
Join Date: Apr 2013
City & State: terrassa,barcelona
My Country: spain
Line Voltage: 230VAC 50Hz
I'm a: Knowledge Seeker
Posts: 39
Default Acer 5740 fan spinning stops after short time

Hi!
have a Acer 5740 wich is shutting down when in full load.
I check the temps and reach 100 degress in a matter of seconds,idle stays with 65-70.
Now,the problem i found is that the fan is not working properly,starts for a few second then stop.
Change thermal paste,clear the dust and reset EC.
Obviously since the fan is not working the processor can"t handle the temps.
Thinking update bios but i am afraid that it could shutting down in the process.(also the baterry is dead)
Any ideea how to solve the problem?
Thanks.
danea is offline   Reply With Quote
Old 09-13-2018, 12:08 AM   #2
mcplslg123
Badcaps Veteran
 
Join Date: Jun 2015
City & State: siliguri
My Country: india
Line Voltage: 220vac,60hz
I'm a: Professional Tech
Posts: 2,308
Default Re: Acer 5740 fan spinning stops after short time

first, replace the fan and see if problem persists. Shutting down after how much time? Exact time every time or not??
mcplslg123 is offline   Reply With Quote
Old 09-13-2018, 07:24 AM   #3
danea
Member
 
Join Date: Apr 2013
City & State: terrassa,barcelona
My Country: spain
Line Voltage: 230VAC 50Hz
I'm a: Knowledge Seeker
Posts: 39
Default Re: Acer 5740 fan spinning stops after short time

hi and thanks for you response
the laptop is shutting down or freeze when put load to processor,monitoring the temp guess is normal since they arrived at 95-100 degrees.
now,the fan start spinning for 5 seconds when boot then is shutting down.
today i observe that the thermal monitor of the cpu is disable and think that not allowed the motherboard to properly activate the fan status.
searching for ways to enable it since the bios does not have such option.
my guess is i am dealing with a bad processor or motherboard.
reflash bios could help but as i said ,afraid not to have the notebook shutdown during te process. notice that the processor power is spec with 25w( HWMONITOR) wich is wrong since is an 35w processor.
Also found this page: https://www.hwinfo.com/forum/Thread-...-How-to-enable ,wich expose the same problem.
Attached Images
File Type: jpg IMG_20180913_114800.jpg (2.78 MB, 15 views)

Last edited by danea; 09-13-2018 at 07:45 AM..
danea is offline   Reply With Quote
Old 09-14-2018, 12:29 AM   #4
mcplslg123
Badcaps Veteran
 
Join Date: Jun 2015
City & State: siliguri
My Country: india
Line Voltage: 220vac,60hz
I'm a: Professional Tech
Posts: 2,308
Default Re: Acer 5740 fan spinning stops after short time

Either replace the fan first as suggested earlier or bypass fan circuit by doing the following:

01. Remove all wires from fan connector except black(gnd). In other words, only black wire will remain in the fan connector.
02. Now connect the red wire to any 3v source from mb.
03.Discard yellow wire for the time being.

Fan should remain always on with this method.

Try and update result.
mcplslg123 is offline   Reply With Quote
Old 09-14-2018, 07:42 AM   #5
Th3_uN1Qu3
Believe in
 
Join Date: Jul 2010
City & State: Bucharest
My Country: Romania
Line Voltage: 230VAC 50Hz
I'm a: Professional Tech
Posts: 5,358
Default Re: Acer 5740 fan spinning stops after short time

Fan is on 5V, if you connect to 3V it will spin with medium speed.
__________________
Quote:
Originally Posted by PeteS in CA View Post
Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
A working TV? How boring!
Th3_uN1Qu3 is offline   Reply With Quote
Old 09-14-2018, 08:39 AM   #6
mcplslg123
Badcaps Veteran
 
Join Date: Jun 2015
City & State: siliguri
My Country: india
Line Voltage: 220vac,60hz
I'm a: Professional Tech
Posts: 2,308
Default Re: Acer 5740 fan spinning stops after short time

Quote:
Originally Posted by Th3_uN1Qu3 View Post
Fan is on 5V, if you connect to 3V it will spin with medium speed.
That wont harm as it will be always on. btw, this is just for test purpose.
mcplslg123 is offline   Reply With Quote
Old 09-14-2018, 12:47 PM   #7
SMDFlea
Moderator
 
Join Date: Jan 2018
City & State: York
My Country: UK
I'm a: Knowledge Seeker
Posts: 3,007
Default Re: Acer 5740 fan spinning stops after short time

On this model its usually the EC bios that gets corrupt,or the KBC dies. Flash the bios and EC with a programmer. The EC is MX25L1005
Attached Files
File Type: zip Aspire 5740 BIOS and EC.zip (1.89 MB, 4 views)
SMDFlea is offline   Reply With Quote
Old 09-15-2018, 12:05 PM   #8
danea
Member
 
Join Date: Apr 2013
City & State: terrassa,barcelona
My Country: spain
Line Voltage: 230VAC 50Hz
I'm a: Knowledge Seeker
Posts: 39
Default Re: Acer 5740 fan spinning stops after short time

well,i could say i solve the problem
First, i was take the risk and flash a mod bios wich has thermal configuracion and many other advanced options enabled.Ventilating the motherboard with a plastic cover it was a succesful flashing despite my fear.
After that the fan had moments when kick on but it was behaving erraticaly.
Then i install notebook fan control with an acer 5738g config. file and that gives me total control of the fan since the bios is not properly control the fan.
I lost my programmer(thinking by a new one)otherwise this BIOS and EC dumps could be very useful.
Thank you all for your advise and your help.
danea is offline   Reply With Quote
Old 09-15-2018, 12:13 PM   #9
danea
Member
 
Join Date: Apr 2013
City & State: terrassa,barcelona
My Country: spain
Line Voltage: 230VAC 50Hz
I'm a: Knowledge Seeker
Posts: 39
Default Re: Acer 5740 fan spinning stops after short time

Many thanks again.

Last edited by danea; 09-15-2018 at 12:21 PM..
danea is offline   Reply With Quote
Old 09-17-2018, 02:35 PM   #10
businessmind1988
Member
 
Join Date: Aug 2018
City & State: ACCRA
My Country: GHANA
I'm a: Knowledge Seeker
Posts: 21
Default Re: Acer 5740 fan spinning stops after short time

i have come across this fault many times and i always measure a different 5v for the Red wire of the fan and it works good
businessmind1988 is offline   Reply With Quote
Old 09-18-2018, 12:14 AM   #11
mcplslg123
Badcaps Veteran
 
Join Date: Jun 2015
City & State: siliguri
My Country: india
Line Voltage: 220vac,60hz
I'm a: Professional Tech
Posts: 2,308
Default Re: Acer 5740 fan spinning stops after short time

Quote:
Originally Posted by businessmind1988 View Post
i have come across this fault many times and i always measure a different 5v for the Red wire of the fan and it works good
exactly that's what i suggested him in the beginning but with 3v to be on safer side.
mcplslg123 is offline   Reply With Quote
Old 09-18-2018, 01:30 PM   #12
danea
Member
 
Join Date: Apr 2013
City & State: terrassa,barcelona
My Country: spain
Line Voltage: 230VAC 50Hz
I'm a: Knowledge Seeker
Posts: 39
Default Re: Acer 5740 fan spinning stops after short time

Grateful for your advise but not have a solder iron or a programmer.
Notebook fan control works great but only in windows envirroment,anyway believe that reprogramming the bios and ec could be a permanent solution.
imagine if i have to reinstall the OS have to dissasembly the notebook in order to properly ventilate de motherboard and cpu to not shutting down because of high temperatures.
And the red wire solution is also a good workaround.
Thanks.

Last edited by danea; 09-18-2018 at 01:33 PM..
danea is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums 2003 - 2019
Powered by vBulletin ®
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 06:49 AM.
Did you find this forum helpful?