Acer E1-531 won't start

[senchire]

Re: Acer E1-531 won't start

Well its the PQ7 which burned down.
Yes I agree its the perfect board, and I will proceed with the fix. Again thank you for pointing me in the right direction.
Now the PQ7 is burned down (the pads aren't in short after I lifted it).
The PU1 isn't burning but since the PQ7 goes in short right away I can't test anything any more. What would be the next step, I love this work learned 1st to reball/reflow this key is missing .

[dj_ricoh]

Re: Acer E1-531 won't start

you say that the pads from PQ7 are not shorted?

Ohms on each pins and without the fet on see the voltage.

[senchire]

Re: Acer E1-531 won't start

O right, am back home. But before I get back to work, someone is offering me this board (E1-531 Intel version). 100% working but he said that the sound isn't being activated (drivers installed but no sound).
Reading on the internet I saw that there is a special version for them (which fixes this bug). He gave me the price 50$ (with cpu and heatsink/vent).
What do you think a good deal?

[ktmmotocross]

Re: Acer E1-531 won't start

when u ffix the bad board u would have good board for max. 10e

[senchire]

Re: Acer E1-531 won't start

I will work on this, but since I got this laptop only to exchange the housing (it worked before), and till my exchange chip's arrive (primary PU1 and PU2 to be sure)
It will be a bit longer and I don't wanna let the client wait for something that I've done if you understand me .

[senchire]

Re: Acer E1-531 won't start

Received today 2 acer's E1-531 without sound (the drivers install normally) but the microphone and speakers aren't detected at all.
The micro's and speakers are 100% fine, could it be some kind of short?

[senchire]

Re: Acer E1-531 won't start

you say that the pads from PQ7 are not shorted?

Ohms on each pins and without the fet on see the voltage.

Ohms on 4 right (D) 2.5Ohms, G and S have 0 reading.
So plug in the dc without PU7?

[vakakush]

Re: Acer E1-531 won't start

Hi
My laptop have Compal la-8241p motherboard and it won't boot. The moment i connect power adapter the adapter turns off. I am unable to boot laptop with power button. There is no sign of life. There is a short circuit somewhere and the moment i connect the adapter's internal connector connected on motherboard i can see a small spark. I have tested some MOSFETS on motherboard and one of them is short. Its labeled as AO4409.

here is the link to schematic
https://cdn.badcaps-static.com/pdfs/...a856347d78.pdf

on page 44 PQ101 is short

Problem 1 - Where does the P2 and P3 points goes which are connected to PQ101?
Problem 2 - I don't know if it is right but my multimeter shows full continuity(BEEP) from GND to P2 and P3. is this correct?


Vakakush

[vakakush]

Re: Acer E1-531 won't start

Update

Today i have removed the MOSFET (it is dead) and only P3 shows continuity to GND is it normal....

Please reply
Vakakush

[vakakush]

Re: Acer E1-531 won't start

update 2

While inspecting the motherboard i encountered this ceramic capacitor. Yellow one on the left side ... Is it broken?
http://s28.postimg.org/abzjtd4rh/2015_07_31_130710.jpg

Capacitor value on schematic is 4.7U_0805_25V6-K

Could someone please tell me. if i am not wrong the correct value is 4.7microfarad 0805size 25volt 10% tolerance.
what does this K stands for?????

When a ceramic surface mount capacitor dies does it shows zero resistance or no conductivity or any of them is possible

[vakakush]

Re: Acer E1-531 won't start

sorry for a typing error.... the question is
Could someone please tell me. if i am not wrong the correct value is 4.7microfarad 0805size 25volt 10% tolerance.
what does this 6-K stands for?????
Could someone please help me with locating a exact replacement capacitor online.

Thanks
Vakakush

[Th3_uN1Qu3]

Re: Acer E1-531 won't start

Yes, that capacitor is broken. And most likely shorted. You have indeed interpreted the schematics correctly - it is 4.7uF 25 volts. You can just take the same size and color capacitor from any spare board and it will work just fine.

[vakakush]

Re: Acer E1-531 won't start

Thanks a lot Th3_uN1Qu3 for your reply.

i have removed this capacitor from motherboard PCB and this badcap is dead (continuity test => short). I have also tested P2 and P3 for continuity from GND and now there is no connection from GND to these two points
Now i can finally solder new MOSFET and Capacitor without any doubt. I have already ordered replacement MOSFET but i am a bit confused about the capacitor.
I am purchasing this capacitor online and i am not aware about the dielectric material that is used in this capacitor. There are so many options to choose online. please tell me which one i can buy....
Dielectric characteristic X5R, X6S, X7R, Y5V and still i am not able to find out what this 6-K stands for ?

Thanks
Vakakush

[Th3_uN1Qu3]

Re: Acer E1-531 won't start

This should help:

Quick rundown: X5R is your basic general purpose ceramic capacitor. X6S, no idea. X7R is a better capacitor than X5R (tighter tolerance, better temperature characteristics). Y5V is the worst. There is also NP0 with excellent temperature stability, but that's for other things like oscillators and timer circuits. I believe they don't make NP0 in uF values, just pF and nF.

6-K is maybe a manufacturer code. Of no interest to you. Your best choice in this case is X7R. Since they're so cheap, order 50 or 100 of them, you'll find them useful in the future.