HP Pavilion DV5-1210EQ Power off after 1 second

[kalin89]

Hello to my favorite electronics forum. You guys helped me many times just by reading through the posts here. Thank you.
Now to the point.
My situation is this :
I have a HP Pavilion DV5 with no signal, fans spin up and capslock blinks with error code "General system board failure". These boards are notorious for their graphical chip going bad. So i did the usual re soldering and heating the vga chip (ATI) and the chipset also.
But now, when i power it up it , the lights come on and after 1 second they go off. During that time the mosfet in the picture below heats up tremendously. Tested it with a Dmultimeter between pins 2/3 and 6/7 and the reading is 66.7 Ohms. THe mosfet is this.
Also found out that the capacitor (also in the picture below ) reads a "Short" when testing with diode (acoustic) test. Is the capacitor causing the heating of the mosfet and my whole problem?
Also how can i recognize what type of capacitor it is ? (How many Farads, voltage? Are these 390 2.5v the values of it? or is it something else?)
Any help of any kind will be greatly appreciated. Thank you.

[ktmmotocross]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

390uF 2.5V

[kalin89]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

Hello again. I have replaced the capacitor and the mosfet displayed on the picture attached above, the problem persists.
I've found out something new though : On the attachment below, the highlighted mosfet is shorted with mass ( PCB Ground ). Is this normal or this presents a further investigation and or replacing of the highlighted mosfet?

[ktmmotocross]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

dont replace mosfets until u know where is that short. remove coils or jumpers to locate the short

[highpulse]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

well my friend , if you don't have a good ESR meter i advise you to locate in which line is located the mosfet were its shunted to ground , and see which voltage line it it . if you don't have a good ESR meter , remove cpu and ram , and imagine for EX it was the 1.8 volts line for ex .. lift one leg of the coil in that circuit part and with black probe of multimeter on the GND and with the RED probe touch in contact were the coil stand (use OHM scale start with 2k and see which values you got on both sides of the coil (with coil lifted) and you should have a higher value in ohm ... if you have for ex 2 or 3 ohm , there is a short and were you notice a very low ohm value solder a wire to that pin(were the coil stand) and start applying a minimal voltage FOR EX (if its 1.8volts line) start applying 1V and give a good bit of current(you must use a good power source (lab source) and start to chek were you found a spot were you will notice some more heat , usually it will take you to the bloody component (attention) this is not the best method but if you don't have a good EST meter to follow the circuit , its the best chance you got to found out were the culprit is .. and in major cases if you reflowed the chipset , you might ended up merging some balls under the bag's making it to give you false encounters with components. it requires time keep us posted of the thing you will found out

[highpulse]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

well checking also now the image you showed us there is no problem with that power mosfet , if computer turn on and off , you still have 19volts power line working , and this powermosfet is on the really beginning on the main 19 volts DC in . focus on the first picture , i really don't have schematics at home , all is at lab to help you out better with this , but if this started to happen after reflowing chipsets , its most probable you damaged on of the chipset , now only checking with schematics i can tell you what have you damaged. so don't carry out more test , until we give you correct answers. i hope it help you out

[sopik78]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

That problem might be on 1.1 and 1.2V power rail, try PQ41 or PQ42, common problem on these laptops.

[kalin89]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

I have found a couple of schematics, but I'm not sure which one is it for my PCB
Here they are :
This one
And this one

[lefos]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

Hello,

First I will try to remove the northchip (the small ati one). It might have got shorted when you did the reflow.

[kalin89]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

Yes indeed the problem started after the reflow of the ATI GRAPHICS chip and the AMD chipset right next to it. I think i will try what lefos said, pull out the AMD chipset next to the graphics chip and test again for shorted components etc. But what is the best way to do that and the safest way to place it back in afterwards ? Never done that before.

[Th3_uN1Qu3]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

Measure on the tiny capacitors on top of both BGA chips. If on any of them you get short (under 1 ohm) the chip is dead and needs to be replaced.

You will need to buy or build a BGA reworking station to replace these chipsets. It takes a lot of practice to learn how to do it.

[ktmmotocross]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

just check resistance to ground on power rails for ATI IGP. i bet it is shorted

[kalin89]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

I tested as Th3_uN1Qu3 said. The tiny capacitors on top of both BGA Chips report a short. They are also shorted with ground ( as seen in picture below). Just for reference i've tested the distant AMD south bridge who wasn't touched at all or heated up. All of his tiny capacitors report 30+ ohms.

[Ramee]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

Change the shorted cap with a good one, see if you get the same reading.

[Th3_uN1Qu3]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

If all caps read short, then one or both of the BGAs are dead. They share the same power supply so if one is dead then the other will measure that way too.

If you don't have reballing tools i would write this one off as beyond repair.

[kalin89]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

Indeed. I wrote this one off. Wasted too much of my time on that already when i have more important projects ahead Thank you everyone for the support on this one. Helped me alot .

[highpulse]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

attention that what you showed us in the picture dont tell that cap is in short , some of the capacitors have one of the sides turned to the GND so its normal that there is continuity , alltough if both sides are making continuity than its not good .
bether to test between each sides on scale of 200ohm , it you have less than 1.1 ohm , then very possible there is a problem with the capacitors or the powerrail that feed that line.
very common on DV5 series , i have now one in the bench with similar problem . cheking very carefuly the 1.2v line

[highpulse]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

alltough mine i found PD1 burned
replaced it and turn the dc in again and noticed the PD1 to get a bit hot , but having the +5vpcu on one side . made a replacement to PU1 sice the capacitor and resistor was ok . then noticed dc led flashing .... cheked that pq41 was not passin the 19 volts , also no 28 v gate on the pin of pq45 , lifted the drain leg of pq45 and instantly dc led light up ,and there is 28 volts on gate so , 19 volts is in short , grabed the power lab source , and found pq42 getting hot . removed the pq42 , and sodlered again the drain of pq45 and board now turn on , and make the one flash caps lock .
ok replaced the mosfet that was burned ,. but once again dc led flash again damaged mosfet . removet mosfet all good again . so cheked resistante to ground no the source of pq42 and i got around 6 ohm ... not enough for short but for sure very low resistance. cheked pq56 and its ok , also cheked pq 41 ok as well , if i chek on continuity it tells me , that PC150 makes continuity t GND as also the coil and the pq41 .. pff getting tired .. so start injecting 1.2 volts , nothin get hot .. cheked with multimeter lab source is gving 1.2 but im readong 0.5 volts , so strt increasing until i have 0,78 volts on board and lab source is at 2.5 volts allreadt and almost one AMP consume .. nothing is hot ... its not possible , its more than 5 w so it would be something getting hot .
any taughts mates ?

[highpulse]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

well guess tomorow will spend more some hours around it

[nkgm]

Re: HP Pavilion DV5-1210EQ Power off after 1 second

If all caps read short, then one or both of the BGAs are dead. They share the same power supply so if one is dead then the other will measure that way too.

If you don't have reballing tools i would write this one off as beyond repair.

A bit late to the party but facing the same problem. Some of the caps on the GPU and NB appear shorted. I trust your appraisal it's the BGA's, but could it not be that the short is happening elsewhere?