Hp 15-dy1731ms not turning on

[mferna14]

Hi all, I am working on Hp 15-dy1731ms (Board # DA0P5DMB8C0 Rev: C ). Upone diagnostics I found one of the rect' diode (A2 1N) near the battery was burnt, I replaced with another good one. Did not turn on. I reprogram the BIOS chip & now the LED on the DC-in jack BLINKS 3 times when the switch is pressed & then shuts off completely. No shorted rail, all looks good. The battery charging chip used is BQ728H .... The voltages on this chip are below:
i) VCC Pin 19 19.4 V Ok (Pin 1-2-3 19V)
ii) ACDET Pin 6 2.0 ( where as this should be 2.6 > )
iii) REGN/LDO/VVDP 5.9V Pin 16 ( seems to be ok)
iv) ACOK 0.3 V Pin 5 (OPEN DRAIN OUTPUT) (Assuming pin should be high on BQ24728, about 3.2V)
V) ACDRV Pin 4 24.2V (Ok)
vi) ILIM Pin 10 1V

Does anyone have the Schematic for this model to share or any tips will be greatly appreciated. Thanks

[SMDFlea]

If you want the schematic you can request it in the schematic requests forum, or add your request to an existing thread - https://www.badcaps.net/forum/showthread.php?t=96880

[mferna14]

Hope I get the schematics in the existing thread. & if anyone wants to shed their knowledge at this problem I am getting in this Hp model. Thanks

[mcplslg123]

ACOK pin uses pull up from 3.3V rail and that rail is usually LDO. Check the resistor connected to pin5 of charging IC. Do you get 3.3V on the other end of resistor?? If so, that indicates presence of 3.3V LDO. Problem seems to be that of ACDET. What is the voltage on AD_ID pin of dcjack??

[mferna14]

Originally Posted by mcplslg123

ACOK pin uses pull up from 3.3V rail and that rail is usually LDO. Check the resistor connected to pin5 of charging IC. Do you get 3.3V on the other end of resistor?? If so, that indicates presence of 3.3V LDO. Problem seems to be that of ACDET. What is the voltage on AD_ID pin of dcjack??

Thanks "mcplslg123" you are always there for help. Pls. check this photo. Similar circuit used on my motherboard. ACOK Pin 5, only get 0.03V & ADETPin 6 2.0V... AD_ID DC-in jack cable, no voltage at all. Hope this photo will help to give me some tips.

[mcplslg123]

Nothing is visible in the pic attached. Did you measured the other end of resistor connected to pin5 of charging IC?? Want to be sure about the status of +3V LDO first. Trace the resistor connected to AD_ID pin of dc jack and measure resistance as well as voltage on both sides of them. Usually 2 resistors are connected to AD_ID pin and they act like voltage divider. Measure voltage on AD_ID pin of SIO also. Which SIO is used here?

[mferna14]

Thanks "mcplslg123" for all the help. This notebook had extended warranty from hp. So I send it for warranty claim. Super I/O was IT5570E-128 , BY THE WAY is this programmable??? 'cause I checked the other IT chips, the KSI pins are totally different on this IT5570E-128.

[mcplslg123]

IT5570E is programmable