Motherboard power LED goes on but quickly goes off, with a “tumble” sound, and this goes on in cycles, while nothing else happens

Joined
Aug 12, 2020
Messages
5
Laptop Toshiba Satellite L850-1V7
Power LED goes on but quickly goes off, with a "tumble" sound, a kind of rising frequency which quickly falls down as the LED goes off, and this goes on in cycles, while nothing else happens, no screen, no fan...

A video of it:
https://drive.google.com/file/d/13dR7WQ_6y-RySQCyqYUWP1oioxTrJcU5/view?usp=sharing
or
https://1drv.ms/v/s!ArkSHQ8jeIoc9SpQ4zh55Yq7aXx_?e=T1TlxO

I bought a new motherboard and a new CPU and everything is still the same. I tried a different power source, but the same happens. The laptop requires 19V. The power sources measure ~20V and 21V. I tried to disconnect every connector and simply connect the power to the motherboard, and still, the same happens.
What does it mean, this type of LED+sound behavior, almost as if trying to power up something, but constantly "giving up"?
 

learners permit

Limp Gawd
Joined
Jun 15, 2005
Messages
329
Search for diagnostic blind code via the led. That may help you to pinpoint the issue a little easier.
 

MeSoHungry

n00b
Joined
May 9, 2010
Messages
12
Have you tried different RAM.
If I recall, many laptops fail to boot with bad RAM and will give a blinking light error code.
 

learners permit

Limp Gawd
Joined
Jun 15, 2005
Messages
329
Well try putting a new cmos battery as no board I've ever seen will work without it. Battery is a cr2032 if I remember correctly. BTW without a heatsink those chips are gonna explode when it does post if they aren't already cooked.
 
Joined
Aug 12, 2020
Messages
5
from my experience, bad charge circuit or a bad psu killing the power circuit.
And it's weird because I bought an entire new motherboard and the exact same happened... The power supply is the constant here. Can the motherboard be so sensible as to not work because of something like +1V?
 

pendragon1

Fully [H]
Joined
Oct 7, 2000
Messages
22,881
And it's weird because I bought an entire new motherboard and the exact same happened... The power supply is the constant here. Can the motherboard be so sensible as to not work because of something like +1V?
could or amps or polarity. when you say new do you mean new from the oem or from some dude on ebay?
 

Spartacus

2[H]4U
Joined
Apr 29, 2005
Messages
2,064
Bad PSU could have killed the second board too.

I've seen a lot of dead laptops from people setting the wrong voltage on the universal power supplies.

.
 
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