HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

[Sephir0th]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

This is not helpful. Voltage measurements are less than half of the "picture". Always check resistance to GND of the rails which are supposed to be up, but not coming up.

I told already, you're probably dealing with multiple issues.

[Crabolog]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

PU8
pin 20 = 19.7v, infinite
pin 16 = 6v, 65kOhm
pin 4 = 25.5v, infinite

PU12 acin = 65kOhm
pu8 acpresent = 77kOhm
acdet 70 kOhm

pu7
phase2 = 9kOhm
lgate2 90kOhm
phase1 20kOhm and rising
lgate1 90kOhm
entrip1 80 kOhm
entrip2 90kOhm
pgood 15kOhm and rising

I'm not sure about power sequence here,what am I missing on pu7 to get powergood ?

[mcplslg123]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

PU12 needs replacement or if you have all the tools and expertise, then cut the track of ACIN pin of PU12. If my memory is not failing PR175 is not populated and rather just a jumper. You need to disconnect ACIN. this pin is connected to charging IC. Actually PU12 is pulling down ACIN on charger IC. hence PU12 and charging IC needs isolation.

However, the best option is to replace PU12 if you are not comfortable with this idea. This fault is quite common on Quanta R53/R33 board.

[Crabolog]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

What should I check if I remove pr175? I still have 0.005v on PU8 pin5. Resistance to gnd is 75kOhms

[Crabolog]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

Same voltage and resistance on PU16 21 pin ACIN = 0.005v
PU8:
ACDET 2.75v
ACN = 19.7V
ACP = 19.7V
VCC = 19.7
CMSRC = 19.7V
ACDRV = 25V
PHASE = 2.8V
SDA =3.3V
SLC = 3.3V
ILIM =3.3V
SRP =2.8V
SRN = 2.8V
HIDRV = 2.8V
LODRV = 0V
BTST = 6V
REGN6v = 5.99V
ACPRES (ACIN) = 0.005V

DC JACK ADID = 0.6v

I'm not sure why acin is missing, will check pr80 and pr79

[mon2]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

ACIN will have a pull-up on the pin as this is an open-drain output.

So there is a logic low but will be floating when the adapter voltage is deemed to be ok. For this reason, the pull-up must be present to define the soft high state.

Check the voltage to ground on each side of the pull-up resistor on this signal line.

[Crabolog]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

I assume pr80 is the pull up resistor here. It has 6v on one pin, and 0.005v on another pin that goes to ACIN on PU8.
I've replaced it and pr79 with new 100k resistors, but no change.
Resistance of pr80 to gnd is 85k, same for pr79

PIN5 ACIN on pu8 has 80k to gnd
Also I have 19.7v on pin1 of PR175 that I've removed, I assume that is not right.

[mon2]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

Personally do not understand the need for PR79 in the circuit.

With both, PR79 & PR80 in the circuit, we have a voltage divider.

On such a design, PR79 should be removed and only an external pull-up (PR80) should be present.

Then the BQ charger can either drive a logic low (ie. 0 volts) onto this signal line OR allow for the pin to float / Hi-Z so that PR80 will pull the line HIGH to the REGN voltage.

Given that you see only 0v on this line and the resistance is not low, this can only mean that the charger IC is driving this pin LOW which results from the charger IC believing that the adapter voltage is absent or too low.

What is the voltage to ground of ACDET pin # 6 (with the power adapter connected) ? This is a threshold voltage that the adapter must meet or exceed to be detected.

[Crabolog]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

ACDET pin 6 of PU8 = 2.75v

[mon2]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

See attached on the conditions that must be met before pin #5 will be in hi-Z state which will then allow for the external pull-up to bring this signal line to a logic '1'.

One of these conditions must be failing here.

[mon2]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

What is the voltage to ground of AD_TYPE ? This is the final shifted voltage used by the EC to detect the capacity of the power adapter. This pin is sampled by an analog to digital converter inside the EC @ U16.

[Crabolog]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

it's 0.598v

[mcplslg123]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

I've already given the solution. PR175 is not populated-so how you removed it? PR175 is a solid trace on motherboard and you need to cut that solid trace to isolate ACIN. Else,simply replace PU12.

[mcplslg123]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

I've attached a image showing which trace is PR175 and where to cut the trace with an arrow.

[Crabolog]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

Issue resolved after changing PU12, thanks

[mcplslg123]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

Issue resolved after changing PU12, thanks

Well, glad to hear that you solved it. But, if you have acted earlier on my suggestion, precious time of others wont be wasted.

[mcplslg123]

Re: HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

I've attached a image showing which trace is PR175 and where to cut the trace with an arrow.

This problem can be resolved without replacing PU12, if you cut the trace at the marked area. have done that on many occassion.