820-2850 dim green light.

2informaticos

Administrator
Staff member
"the fan spinning for 20 sec"
Why do you talk about pulsing now?
I was waiting to get some voltages present in the 20s mentioned.
You cannot say pulsing when the board stays on 20s; unless you note some pulse in these 20s...

BTW, C9560 shouldn't be related with this symptom, but it must be changed in any case.
So change it now, to discard it completely.
Do NOT use hot air for this!
 

Chuck60

Member
im sorry What I meant was that the pulsing coincides with fan on and off or at the same time
the coils as I mentioned only showed a voltage L7330
it goes up to 3.3v then to zero. So when fan spins it at 3.3v when off it goes to zero the only other rail I found that does this is ppv1v5_s3 and gets power from pp3v3_s3 which isn?t pulsing on off it stays stable all the time.
 
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2informaticos

Administrator
Staff member
If fan spins, 5V_S0 is needed.
PLEASE post accurate information.
There are more voltages present for sure.
To get 5V_S0, PPBUS_G3H is required, as 3V3_S5 too.

BTW, ALWAYS check coils voltage on the pin connected to filter capacitor.
 

Chuck60

Member
Fan on. Fan off
L7330. 1.5v. 0v
L7530. .8v. 0v
L7630. 1.07v. 0v
L7415. Pulsing every second
L7425 .8v. 0v
L7030. 12.52v 12.52v
L7630. 1.07v. 0v
L8920. .9v 0v
 

Chuck60

Member
Here are the coils voltages you asked for
 

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2informaticos

Administrator
Staff member
I don't understand how can you have different behaviour on L7415/25; as both are connected together.
Remember to check voltage on the coil pin connected to the filter cap!!!

Post again L7415/25 voltage.
Also post exact ohm voltage to ground; compare with good board.
Check traces and resistors around U7400.
 

2informaticos

Administrator
Staff member
Do you mean steady 0.8V?
I doubt you have 8V there...

Can you note a drop from initial 1.15V to 0.8V in few seconds?
Or you get 0.8V from the first moment?
 

2informaticos

Administrator
Staff member
Looks like CPU works in such case.
Check for USB activity in the 20s when board stays on.
Don't forget about C9560...
 

Chuck60

Member
Ok I order the bios programmer. I have replaced the resistor and cap we spoke of now I have pm_slp_s4_l
Turning on with fan spins then off when the fan stops. As i under stand this is the enable signal for pp5v_s3
It also acer power cycling for a minute or 2 the fans spin full speed. im gonna look around. I believe it comes from pch so maybe something in the circuit in between
 
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Chuck60

Member
Still turns off and it?s more like 8 seconds now. I?ve fixed many other boards this one just trolls me :/
 
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