HP 6735s power plug blinking blue

[primoz1]

Hi again, I got this laptop and when connect power connector to laptop just blinking blue led light look video here http://tinypic.com/r/1b60l/5

Is no change if remove battery, memory, HDD od DVD the power button no react at all.

Any idea where to start ?

Thankyou

[marcellodj]

Re: HP 6735s power plug blinking blue

shorted north bridge?

[primoz1]

Re: HP 6735s power plug blinking blue

Hi. I dont know if is northbridge, GPU chip has overheating signs, a little blue shade on core, while north bridge no visible traces of overheating.

[selldoor]

Re: HP 6735s power plug blinking blue

This "might" be a schematic for it - I dont know for certain- perhaps you can tell by comparing with your machine

http://lqv77.com/download/540/

[mattbrad2]

Re: HP 6735s power plug blinking blue

Ruled out the AC adapter? Remember, these newer HP units are even worse than Dell as far as their center pin communication. Problems like this are usually pretty obvious if you open it up and visually inspect the motherboard.

[primoz1]

Re: HP 6735s power plug blinking blue

Hi. I use multimeter and check voltage on connector voltage on little pin and inside wall of connector both has a + outside is - and on inside + got 19.50 v on little pin + got a 18.02 v

Like on picture attached, is possible to that 1 volt diference cause this defect ?

[elbostan]

Re: HP 6735s power plug blinking blue

you `ve short in your mother bord

[primoz1]

Re: HP 6735s power plug blinking blue

Maybe is, but what can be shorted ?

[mattbrad2]

Re: HP 6735s power plug blinking blue

Hi. I use multimeter and check voltage on connector voltage on little pin and inside wall of connector both has a + outside is - and on inside + got 19.50 v on little pin + got a 18.02 v

Like on picture attached, is possible to that 1 volt diference cause this defect ?

You can't test these just with a DMM. That center pin carries a serial signal to the mainboard. This will not register on a DMM, only on a scope. In fact, that light you see is directly controlled by this signal. The power management IC reads info from this serial pin then turns on your 3v standby rail ONLY if it gets a valid reading (at least, that is how most newer HP laptops work). Its from this 3v rail where you get that blue light. Now, in saying all this, your problem is still probably motherboard related but its nice to rule out the little things first.

[primoz1]

Re: HP 6735s power plug blinking blue

Ok. I will try found good AC adapter.

Thankyou.

[primoz1]

Re: HP 6735s power plug blinking blue

Hi. I use another AC power adapter and come up both lights beside power connector on board, but laptop is dead again. I spot two element was heating app. over 100c and I remove both, then start heating one beside this two, and I change all 3 elements from similar motherboard, and again not work it all.

[b700029]

Re: HP 6735s power plug blinking blue

You can't test these just with a DMM. That center pin carries a serial signal to the mainboard. This will not register on a DMM, only on a scope. In fact, that light you see is directly controlled by this signal. The power management IC reads info from this serial pin then turns on your 3v standby rail ONLY if it gets a valid reading (at least, that is how most newer HP laptops work). Its from this 3v rail where you get that blue light. Now, in saying all this, your problem is still probably motherboard related but its nice to rule out the little things first.

Also, placing any sort of voltage on the center pin above 3-5V is a bad idea. If this is similar to the Dell design there is a 1-wire serial EEPROM between the center pin and ground (they should really be called "2-wire"). Those are not designed to withstand voltages above 5v.

Hi. I use another AC power adapter and come up both lights beside power connector on board, but laptop is dead again. I spot two element was heating app. over 100c and I remove both, then start heating one beside this two, and I change all 3 elements from similar motherboard, and again not work it all.

I see two diodes there. Use the schematic and look up the right part number. "similar" may not be good enough. I suspect there is something shorted beyond the power circuitry.

[pslooks]

Re: HP 6735s power plug blinking blue

Please im new here, i have problem wih 6735s..... displa underground but not inverter, d screen is ok, signal cable ok..... please help me on dis issue. thanks

[pslooks]

Re: HP 6735s power plug blinking blue

Hp mini 110 issue, do not power with battery, but charging

[pslooks]

Re: HP 6735s power plug blinking blue

sony VGN N21Z charging, but battery does not increase please what can i do. pls help

[it.vendor]

Re: HP 6735s power plug blinking blue

Please im new here, i have problem wih 6735s..... displa underground but not inverter, d screen is ok, signal cable ok..... please help me on dis issue. thanks

hi there,
1-try to check your lcd by connecting with some other ok laptop, means confirm the lamp of your lcd is ok...
2- if your lamp is ok ...thats fine...if not change your lcd's lamp.\
3-if lamp is ok....check 12-18 volts of your F/L invertor or fuse that would be veryclose to the jack...

[gcomputers]

Re: HP 6735s power plug blinking blue

Hi i have similar problem with hp 6735s powerjack blink yellow blue continuously.
I checked it and i find Q37 too hot replaced it no change , all pins of Q37 ,Q36 , (Q47 pin 2345678 ) are shorted with ground, also removed U19 but the same short ????
Another problem that i find is Q1031 pin 123 shorted with pin 4567 but replaced with another and ok short has gone.

The problem is short of Q37 Q36 Q47

Any help please?