HP G62 Quanta AX3 No power

[p1muserfan]

Re: HP G62 Quanta AX3 No power

Probably not much help but found PR160 to be 8K ohms instead of 100 ohms so after change now have .5v to gate of PQ47. Problem is, now have that same .5v on output of PQ47 too, is it leaking?
And because I have 26v on one side of PR158 but 0 on the other, it take voltage across PR155 to "draw" the voltage across PR158 too?

[khaahk]

Re: HP G62 Quanta AX3 No power

Basic idea is that there must be a much lower resistance than 150k after pr158. Only then the voltage can drop after pr158 to near 0.
On first posts you have confusing numbers - saying that you have 4.8v at pin2 of PQ51 and the #5 post you say that ACPRN is 0v. But they must be connected to each other...

[Th3_uN1Qu3]

Re: HP G62 Quanta AX3 No power

The end of PR158 connecting to the gate of PQ147 can be 0 for 4 reasons:
#1: ACOK_IN is 0 volts,
#2: ACOK# (driving PQ51) is high (>2 volts)
Both of which indicate a problem elsewhere, most likely in the adapter sensing circuit.

#3: PQ47 has gone leaky from gate to source. Check resistance on the board between gate and source of PQ47 with the multimeter set to 2M Ohms (or 2000kOhms as shown on some meters). It should read open/over range. If it reads anything else, replace PQ47.
#4. PQ51 shorted between drain and source, pulling the gate of PQ47 low even though ACOK# is 0 volts. If that is the case, replace PQ51.

[meritosari]

Re: HP G62 Quanta AX3 No power

The end of PR158 connecting to the gate of PQ147 can be 0 for 4 reasons:
#1: ACOK_IN is 0 volts,
#2: ACOK# (driving PQ51) is high (>2 volts)
Both of which indicate a problem elsewhere, most likely in the adapter sensing circuit.

#3: PQ47 has gone leaky from gate to source. Check resistance on the board between gate and source of PQ47 with the multimeter set to 2M Ohms (or 2000kOhms as shown on some meters). It should read open/over range. If it reads anything else, replace PQ47.
#4. PQ51 shorted between drain and source, pulling the gate of PQ47 low even though ACOK# is 0 volts. If that is the case, replace PQ51.

Sorry, add comment to correct that look like mistype, Its should be PQ47

[p1muserfan]

Re: HP G62 Quanta AX3 No power

The end of PR158 connecting to the gate of PQ147 can be 0 for 4 reasons:
#1: ACOK_IN is 0 volts,
#2: ACOK# (driving PQ51) is high (>2 volts)
Both of which indicate a problem elsewhere, most likely in the adapter sensing circuit.

#3: PQ47 has gone leaky from gate to source. Check resistance on the board between gate and source of PQ47 with the multimeter set to 2M Ohms (or 2000kOhms as shown on some meters). It should read open/over range. If it reads anything else, replace PQ47.
#4. PQ51 shorted between drain and source, pulling the gate of PQ47 low even though ACOK# is 0 volts. If that is the case, replace PQ51.

Nothing at gate of PQ47 because
#1: ACOK_IN is 0 volts because AD_ID pin of connector connects to R62>D16>+3VPCU>EC. Once EC has power it can generate D/C# signal for PQ7 which will then output 26V across PR155 to gate of PQ47.

On working board I have 1.5v to D16/3.3v out. On crap board about 1.3v in D16/.8v out=not enough to power EC. What raises the voltage on the other side of that diode? Because both diodes measure the same.

#2: ACOK# is fine, almost 0

#3 Checked resistance of PQ47 gate/source while on board, only measures 155 ohms, so I removed it. Measures out of range off the board but the pads on the board measure 155 ohms, how is that?

#4 PQ51 not shorted drain/source.

[khaahk]

Re: HP G62 Quanta AX3 No power

On working board I have 1.5v to D16/3.3v out. On crap board about 1.3v in D16/.8v out=not enough to power EC. What raises the voltage on the other side of that diode? Because both diodes measure the same.

On working board the source of the 3V is somewhere else i think. PU5 might be working?

How does PQ50 measure off the board?

[Th3_uN1Qu3]

Re: HP G62 Quanta AX3 No power

On working board I have 1.5v to D16/3.3v out. On crap board about 1.3v in D16/.8v out=not enough to power EC. What raises the voltage on the other side of that diode? Because both diodes measure the same.

#3 Checked resistance of PQ47 gate/source while on board, only measures 155 ohms, so I removed it. Measures out of range off the board but the pads on the board measure 155 ohms, how is that?

Something's pulling it down, check all parts that connect to PQ47 gate, remove one by one and recheck resistance. The cathode of D16 not reading 3.3v is not your problem as that goes to 3VPCU (3VALW) which only comes up once power goes thru PQ47, and on your board it does not.

EDIT: You say you have 155 ohms gate to source on the pads of PQ47 but mosfet is fine. Remove PC156 and PC158 and recheck.

[p1muserfan]

Re: HP G62 Quanta AX3 No power

Something's pulling it down, check all parts that connect to PQ47 gate, remove one by one and recheck resistance. The cathode of D16 not reading 3.3v is not your problem as that goes to 3VPCU (3VALW) which only comes up once power goes thru PQ47, and on your board it does not.

EDIT: You say you have 155 ohms gate to source on the pads of PQ47 but mosfet is fine. Remove PC156 and PC158 and recheck.

PQ50 was causing low resistance between gate and source of PQ47 pads, that's fixed.
Still need 26V out of PQ7 to PR155. D/C# signal from EC of good board is .002, bad board .08. Signal too high on bad board?

[p1muserfan]

Re: HP G62 Quanta AX3 No power

Disregard last statement of last post, I think I get it now. PQ7 does not generate 28V, only PU4 does. PQ7 and 51 are there to kill PQ47 if something wrong is detected on board.

[stingerchamp]

Re: HP G62 Quanta AX3 No power

PR158 is my problem then because I have 28v on one side but nothing on the other. It does measure 150k like it should so why no voltage on the other side?

Just want to share solution if anyone else stuck here

if you have 28 Volts on one side of resistor directed towards gate of switching mosfet and not other side, change the resistor , you just found solution

current is not reaching till gate and that is why there is no high voltage

[stingerchamp]

Re: HP G62 Quanta AX3 No power

Hi,


Did you find the solution

if ADP_ID is low like 1 volt, it means adapter is faulty or providing OVC?

[piernov]

Re: HP G62 Quanta AX3 No power

Voltage on AD_ID/ADP_ID/LIMIT_SIGNAL (or whatever it is on whatever HP board you're working with) depends on the board and on the AC adapter used. It's the output of a voltage divider between 19V and ground, upper resistor is inside the AC adapter connected to 19V and adapter ID signal, lower resistor is on the board connected to adapter ID signal and ground.

On this board lower resistor is R61 which is 23.3k, using 90W AC adapter where upper resistor is around 330k, voltage will be around 19*23.3/(23.3+330) = 1.25V.

[stingerchamp]

Re: HP G62 Quanta AX3 No power

Hi
Thanks but it is a 150 watt adapter, 19.5 DC and 7.7 ampere