5 Posts
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3626
Inspiron 7577 won't boot in any way
Hey everybody,
so I it seems that I already managed to brick my inspiron 7577 unless you can help me. This was not my first teardown with this notebook and after the first everything worked normal.
Three weeks ago, one of the fans made very loud noises and I decided to change them. So I got these today and another time I teardown until I get to the fans, replaced them and this time I disconnected the bios battery (for no reason). I put all together and I couldn't start the notebook since then. What I allready tried:
- Boot with the power cord insert --> no boot, no sign of life
- Boot without the power cord, from battery --> keyboard lights up but no status led, no fans spinning no screen
- Boot with the old fans--> same as above
- Boot with ctrl + esc and put the power cord in--> keyboard lights up but no status led, no fans spinning no screen
There is no cable physical damaged, no connector broken, I touched nothing but the fans I had to change, the fans are optical the same and fit exact as the old ones. And the only thing I changed in my procedur since the last time (that worked fine) was to disconnect the cmos battery
If somebody can help me I'll be very pleased.
Thanks,
Tom from germany
Tomohnejerry
5 Posts
0
March 12th, 2020 13:00
Thanks for helping I found the solution on myself.
started the laptop with the fans in front of me I saw that they had trouble spinning up so I again put in the old ones and tada fan spinning system booting.
There was a faulty cable on one of the new fans. So I fixed that and my laptop is running again.
So yes, if the pwm Signal from your fans is faulty you won’t be able to start your laptop without new fans.
JOcean
7 Technologist
7 Technologist
•
12K Posts
0
March 10th, 2020 11:00
Either something is not plugged in all the way or correctly like the CMOS battery, or the motherboard is shorting out due to a loose screw for example laying on the motherboard. Of course it is possible that the BIOS had a static shock during the service.
Tomohnejerry
5 Posts
0
March 10th, 2020 13:00
I already checked if there is something wrong witch the connections or on the board.
There is no screw missing or left over. It ok some pictures for showing the mb in my case.
Is there any work around, getting a POST? I’m an expert with IT Systems but without anything else then that I cannot do anything.
I also cleaned up any connector and plug with isoprop. After reassembling it keeps not spinning up the fans or showing any other sight of life then lighting up the keyboard (I mentioned that the components getting warm in this state)
Tomohnejerry
5 Posts
0
March 10th, 2020 21:00
The question is, can the laptop only start after getting okay signal from fan pwm control?
If so then I can imagine, that the new fans could have damaged the pwm control so the laptop stuck in the “system check” because there is no fan okay signal.
My question is, is there a pre post check which could affect the notebook behavior?
Tomohnejerry
5 Posts
0
March 11th, 2020 09:00
So a little bit of order in this chaos. The following behavior are reproducible:
1. Unplug the battery, plug in the power cord and push the power button—> 30sec Keyboard backlight, no Fan spinning, no video
2. plug in the battery, unplug the power cord and push the power button—> 30sec Keyboard backlight, no Fan spinning, no video
3. plug in the battery and the power cord and push the power button—> no keyboard backlight, no fan spinning, no video