acer aspire 4736z power problem

[red_raian]

help to find these kind of problem,

their is a supply for several parts esp. power P CHANNEL FETS, MAIN CAPACITOR, FUSE up to charging management the ISL******, PIN 1 3.*** AND 28 PIN 18.***, anybody here teach me where other parts may have a problem.. i was not able able to fix this kind of problem so i need you ideas guys here.

thanks in advance!!

more power BCF!

[tedjo]

Re: acer aspire 4736z power problem

Hi ... I have 4736 power problem too...
Lets discuss it here .

My mobo problem just blink power led, and sometimes will power on but nothing on screen ...

[nish_pinto]

Re: acer aspire 4736z power problem

I have the same problem too. I happened to find a NEC/TOKEN cap, is that the culprit?

[nish_pinto]

Re: acer aspire 4736z power problem

I removed the NEC/TOKEN(0E907) cap and replaced it with 4x330uf smd tantalum caps, dint work. then i used 2x330uf and 2x470uf tantalum caps. Bloody, now even the leds dont blink. somebody please help. Btw I used a smd rework station, just brought today.

[Ch1p4@ll]

Re: acer aspire 4736z power problem

no clue? i got the same problem...
but i think fixing nec/tokin only work for toshiba (Hang on charging, didnt start,always hang)
i doubt the BIOS fail to start for acer problem (only led on, led blink) *note (intel GMA board)

it happen on many type of acer aspire notebook.

[b700029]

Re: acer aspire 4736z power problem

http://lqv77.com/download/614/

Is schematic helpful?

[2kang]

Re: acer aspire 4736z power problem

I removed the NEC/TOKEN(0E907) cap and replaced it with 4x330uf smd tantalum caps, dint work. then i used 2x330uf and 2x470uf tantalum caps. Bloody, now even the leds dont blink. somebody please help. Btw I used a smd rework station, just brought today.

I replaced with NEW NEC/TOKEN(0E907) .. didn't work too.. Vcore = 0 volt.

[boodeey]

Re: acer aspire 4736z power problem

OE907 = 900 uF
Try => (3 x 220 uf) + (1 x 330 uf)

www.servicenotebookjakarta.com

[b700029]

Re: acer aspire 4736z power problem

I replaced with NEW NEC/TOKEN(0E907) .. didn't work too.. Vcore = 0 volt.

Unless the cap is shorted, vcore won't be at 0V. Trace the vcore back to the MOSFETs and make sure those haven't failed open and are getting the right drive signal from the controller.

[xaviero1412]

Re: acer aspire 4736z power problem

agreed with b700029
if not shorted caps, there will be a voltage.
if that sure not shorted, check the ISL6262 , that is Vcc_core generator IC. try resolder first, if not then try replace it.

[delaware74b]

Re: acer aspire 4736z power problem

I am working on an Acer 7736 series laptop with no power problem. It has a short in the power supply section, turns off the ac adapter and no power from battery.

I found 2 shorted mosfets (FDS6690AS and FDS8884) located on bottom edge of JV71-MV mobo, below the memory sockets. These are controlled by the ISL62392 IC and it generates the +3.3 and +5V for the mobo. I have the mosfets removed and the short-circuit is gone from the mobo and the ac adapter isn't shutting down when I plug it in.

Apparently, this is a common issue on this particular mobo.

[xaviero1412]

Re: acer aspire 4736z power problem

I am working on an Acer 7736 series laptop with no power problem. It has a short in the power supply section, turns off the ac adapter and no power from battery.

I found 2 shorted mosfets (FDS6690AS and FDS8884) located on bottom edge of JV71-MV mobo, below the memory sockets. These are controlled by the ISL62392 IC and it generates the +3.3 and +5V for the mobo. I have the mosfets removed and the short-circuit is gone from the mobo and the ac adapter isn't shutting down when I plug it in.

Apparently, this is a common issue on this particular mobo.

pardon, may i ask, i am wondering bout "shorted mosfet"....
what method did u use to find the "shorted mosfet" ???
thanks

[severach]

Re: acer aspire 4736z power problem

Removing the MOSFETs to stop the shorted power supply is not sufficient. That's no better than unplugging the power. You need to test the MOSFETs and the motherboard pads to see which is shorted. Unless the removed MOSFETs are obviously burned, my bet is the short is still on the motherboard.

[delaware74b]

Re: acer aspire 4736z power problem

In my case, the pair of mosfets showed a dead short on pins 1 to 8 on both. I lifted pins 1-4 off the mobo solder pads enough to remove the mosfets from the mobo circuits.

Using my meter, the mosfets were definitely shorted. I reconnected the ac adapter to the mobo and it no longer went into short-circuit protection. I also checked the mobo where the mosfets were connected, no short circuit condition exists.

The shorted mosfets had no external indication of being shorted. I have seen mosfets after they have released all their magic smoke.

[xaviero1412]

Re: acer aspire 4736z power problem

In my case, the pair of mosfets showed a dead short on pins 1 to 8 on both. I lifted pins 1-4 off the mobo solder pads enough to remove the mosfets from the mobo circuits.

Using my meter, the mosfets were definitely shorted. I reconnected the ac adapter to the mobo and it no longer went into short-circuit protection. I also checked the mobo where the mosfets were connected, no short circuit condition exists.

The shorted mosfets had no external indication of being shorted. I have seen mosfets after they have released all their magic smoke.

so, just check with diode-test/continuity-test to measure short or not. is it correct ???

[delaware74b]

Re: acer aspire 4736z power problem

I used the 30megohm-range on resistance check. Continuity 'beep' mode on my meter trips at 300 ohms or less. I had a 'hard' short with the two mosfets in circuit. After I lifted pins 1-4 on each one, I tested both the circuits on the mobo and the mosfets. The mosfets were definitely still in shorted condition even after completely from the board.

[red_raian]

Re: acer aspire 4736z power problem

Hi ... I have 4736 power problem too...
Lets discuss it here .

My mobo problem just blink power led, and sometimes will power on but nothing on screen ...

charging pin, just reflow it..

[xaviero1412]

Re: acer aspire 4736z power problem

I used the 30megohm-range on resistance check. Continuity 'beep' mode on my meter trips at 300 ohms or less. I had a 'hard' short with the two mosfets in circuit. After I lifted pins 1-4 on each one, I tested both the circuits on the mobo and the mosfets. The mosfets were definitely still in shorted condition even after completely from the board.

thanks for the great info....

[johnwafu]

Re: acer aspire 4736z power problem

i have the same problem at first it has a power indicator and black screen then i tried replacing ram and processor but same problem occur.

tried replacing the nectokin with 2 +330 cap

then it has a display now but the problem now is you cannot shutdown the unit it always auto on

tried replacing 4 +470 on netokin same problem
tried replacing 2 ne 220 same problem
tried replacing 4 ne 220 same problem

any ideas sir?

i have not yet tried the 220 negative and 330 negative

[Madhusha]

Re: acer aspire 4736z power problem

I used the 30megohm-range on resistance check. Continuity 'beep' mode on my meter trips at 300 ohms or less. I had a 'hard' short with the two mosfets in circuit. After I lifted pins 1-4 on each one, I tested both the circuits on the mobo and the mosfets. The mosfets were definitely still in shorted condition even after completely from the board.

My DMM is Sanwa "CD800a" I'm using some different way to hunt shorted caps,it s worked for me... my DMM Buzzer working for below 50ohms only & also it shows the value while it buzz. I jst take two wires from shorted path(cap's + & -) then clip DMM probes to those,on buzz mode(continuity)(it buzzes now:-), using hot-gun & a tweezers lifting and putting back caps,fets,diodes one by one until buz gos off... its worked for meeeeee