Dell Inspiron 1545 no lights no power

[rippergr]

Hello all,
I have a isnpiron 1545 which seems to get power but it doesn't do anything when I pres the on button.
I checked the dc jack and I used bench power supply to give 19,5 V.
I have 19V on U47 and in U7 in pin 2 I have also 19V
Where should I check if I have output voltage from U7?

[rippergr]

Re: Dell Inspiron 1545 no lights no power

Anyone who can help me?

[rookieme]

Re: Dell Inspiron 1545 no lights no power

U7 pin2 seems to be wrong.
The maximum voltage could be 6V according to the datasheet.
This could be problem at voltage divider [shorted R52] or faulty U7.
Try to remove R52 and measure again voltage at U7 pin2.

[rippergr]

Re: Dell Inspiron 1545 no lights no power

Sorry , this was my mistake , I mistype the pin
In U7 pin22 I have 19 V
in U7 pin2 I have 2,34V
Can you tell me what pin is the output voltage to check in U7 ?

[rookieme]

Re: Dell Inspiron 1545 no lights no power

U7 pin 3 should be around 4,1 V and pin 2 around 2 V.
At U47 pin 1 you get 19V?
If yes don't bother measuring U7.

[rippergr]

Re: Dell Inspiron 1545 no lights no power

Yes U47 pin 1 has 19V.
So the problem is not in U7.
What else can I check, how should I continue?

[rookieme]

Re: Dell Inspiron 1545 no lights no power

Now you should check L13 for 3V and L15 for 5V.
You should see both of them.