Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

[mferna14]

Hi all., I am working on this Hp 15-cc523ca MB DAG71MB16D0 Rev D. It had the SY8288CRAC BURNT, I replaced it & then no shorts on the 19v rail but still did not turn on. I updated the BIOS Bin & re-soldered the BIOS IC, but still no luck. AD ID is just 0.68 volts & like to share the voltages on PU10 (SY8286BRAC) & PU11 (SY8288CRAC). LED not glowing white/orange on the DC-in jack. Any help would be appreciated. Thanks

PU10 SY8286BRAC
PIN1 - 2.8V
PIN2 - 19V
PIN3 - 19V
PIN4 - 19V
PIN5 - 19V
PIN6 - 0V
PIN7 - 0V
PIN8 - 0V
PIN9 - 0V
PIN10 - 0V
PIN11 - 4.5V
PIN12 - 0.015V
PIN13- 0V
PIN14 - 0V
PIN15 - .32V
PIN16 - 0V
PIN17 - 3.3V
PIN18 - 0V
PIN19 - 0V
PIN20 - 0V


PU11 SY8288CRAC
PIN1 - 3.8V
PIN2 - 19V
PIN3 - 19V
PIN4 - 19V
PIN5 - 19V
PIN6 - .6V
PIN7 - 0V
PIN8 - 0V
PIN9 - 0V
PIN10 -0V
PIN11 - 4.5V
PIN12 - 0.015V
PIN13- 1.5V
PIN14 - .60V
PIN15 - 0.06V
PIN16 - 0V
PIN17 - 3.3VV
PIN18 - 0V
PIN19 - .609V
PIN20 - .609V

AD ID is .68V

[mon2]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

What are the specs of the DC power adapter being used for these tests ?

What is the voltage of the AD_ID pin without connecting the logic board ?

[mferna14]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

What are the specs of the DC power adapter being used for these tests ?

What is the voltage of the AD_ID pin without connecting the logic board ?

Thanks mon2... The power adaptor is the same I use for every hp 19V 3.42amp ... The power AD_ID on the DC-in Jack connectors is 19.34V

[mcplslg123]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

AD_ID is correct. Dont mess up un-necessarily here.
PU10,Pin17 is +3V LDO. This is needed for EC to be powered and light at dc jack. So check for pin17. Most likely +3V LDO is missing. Next check resistance on +3V LDO?? If low very likely kbc shorted. So proceed in this direction and update.

[mferna14]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

Thanks mcplslg123 . I did inform you that the voltage on PU10 pin # 17 is 3.3v. Now only thing is left to check the resistance level, maybe the KBC is shorted too. I even get 3.3v on the ON/OFF button for powering on. & some say that PIN 11 should 19v, is this true as I am only getting 4.5v?? I will surely check all your guidelines & inform you once I get a solution.

[mferna14]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

I checked the resistance level between ground & LDO points near & on the KBC, it's around 142Kohms, so it not shorted & the voltage is 3.3 volts on all these points. But still this connector LED not turning on. I even re-programmed the BIOS, on the 5v coil, I am getting around .609V. I checked the whole motheboard, no components are shorted. What could it be????

[mon2]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

For the 5v coil - which regulator is driving this leg of the circuit ?

Respectively, this regulator will offer an ENABLE pin. Confirm the voltage of this pin so that we know that the upstream logic for this ENABLE is requesting to turn on this rail.

If this is an always ON rail then this regulator is not working properly and could be defective or improperly soldered.

Post the voltage readings of all pins of this regulator and the part number.

Do you have a schematic for this logic board ? Please link it if on this forum. If not, the details of the regulator should be enough to study by example from other schematics.

[mferna14]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

There are two Enable pins in PU10.. pin 11 has 4.5v & pin 12 is 0v... On top all voltages of PU10 & PU11 are listed.. I have attached the schematics. Please view. I even have the Boardview if required.. Thanks for the help

[mcplslg123]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

Sorry, i overlooked the presence of +3V LDO on PU10. Voltage on Pin11 is absolutely correct, dont go by what people suggest. calculate it yourself. There is a voltage divider involved (PR3264/3268). So 19v(vin)X 150(R2) divided by 499(R1) + 150(R2) will give you exactly 4.4V. So dont get confused when you have schematics. So PU10 seems functional.

PU11 is not working properly as you should get +5V LDO on pin15. So replace PU11 and update.

[mferna14]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

Thanks mcplslg123., I will try this. Just to inform you does this matter, I used SY8288RAC (AWS56A) instead of the original SY8288CRAC (BAC7XM), Does this make a difference & because of this change I am not getting the correct voltages. (I am assuming that they both are the same with same pin configrations & both above chips are the 5v regulators), pls. inform me if this is the mistake I made???

[mcplslg123]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

I've never interchaged them and not sure whether you can do so. Better to replace with exact parts.

[mon2]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

PU11 is not working properly as you should get +5V LDO on pin15. So replace PU11 and update.

This is most likely due to the a different version of the part being soldered @ PU11.

The suffix is very important and fairly sure that the 'C' suffix denotes that the +5V LDO is always ON.

Source the exact part number device from Aliexpress or a donor board and test again.

SY8288CRAC

[mferna14]

Re: Hp 15-cc523ca MB DAG71MB16D0 missing 3.3/5V

Thanks, I will do that & inform you once I get the part replaced. Your help is greatly appreciated.