HP Pavilion 23 All In One- No power up

[meritosari]

Re: HP Pavilion 23 All In One- No power up

I hope this could help you as reference.

[Herbssat]

Re: HP Pavilion 23 All In One- No power up

Thanks Meritosari. What critical voltages should be checked on the kbc besides the power switch and vcc? Also looks like vstby is tied to 3v line. Appreciate your help.

[meritosari]

Re: HP Pavilion 23 All In One- No power up

I think you should find signal from KBC after pressing power button like RSMRST#....
you should find ACIN, LID, after you plug in adapter. if the signals was ready, then can not power on maybe bios problem

in my mind the chipset like big machine, KBC like control panel to operate, control and maintenance that machine (====logical thinking)

[Herbssat]

Re: HP Pavilion 23 All In One- No power up

Thanks for the info. Will check voltages on the kbc and let you know the outcome. I am still looking for the 3/5 volt regulators.

[meritosari]

Re: HP Pavilion 23 All In One- No power up

I'm pretty sure you have 3.3v/5v LDO voltage. because you have 3.3 voltage at power button. but unit can't power on so you have no voltage 3.3vs5/5vs5.
you can confirm this voltage if you already have 3.3v at KBC (pin26, 50 92 and so on)


I think this unit was current product that using new DC/DC IC like product from MPS ie NB669, NB670, NB671

I suspect red box area is right location where dc/dc block on it

[Herbssat]

Re: HP Pavilion 23 All In One- No power up

Thought we were on to something with finding the regulators but the step down converters I see belong to the ti family in that area(tps51211 and 51216). There are some others in that area that I need a better visual image to see the markings. Will try to get some other pics up. The board picture looks identical though.Thanks for your help.

[Herbssat]

Re: HP Pavilion 23 All In One- No power up

Need to look up data sheet on winbond bios ic. If I recall correctly there was no voltage at any pin. Is that voltage being released from the kbc? The ec sp1 has voltage at 3 pins. Thanks.

[Herbssat]

Re: HP Pavilion 23 All In One- No power up

Bios chip is actually a Micron 25Q064A. As said earlier no supply voltage at all. Is it possible to inject 3v and see what happens?

[meritosari]

Re: HP Pavilion 23 All In One- No power up

why inject voltage at Bios chips? I think its not change anything

Did you check at KBC if any voltage like 3.3v?

[Herbssat]

Re: HP Pavilion 23 All In One- No power up

Thanks meritosari. Just a thought. I have looked at KBC pins 11 and 26. No vcc voltage at pin 11 if my meter is contacting the pin correctly but 3.3v is at pin 26. Looks like I have vcore of about 1.8v on pin 12 if I am reading the orientation of the chip correctly. Reading left to right from the little dot at the bottom. Very aggravating to check.

[Herbssat]

Re: HP Pavilion 23 All In One- No power up

I have confirmed there is no vcc voltage to SIO chip. A continuity check shows that pin 11 is connected to a Q7009 with the marking E4 GUB 5Q1805 if anybody can help me identify it. Thanks.

[Herbssat]

Re: HP Pavilion 23 All In One- No power up

Any ideas on the ic previously mentioned?

[meritosari]

Re: HP Pavilion 23 All In One- No power up

- you get correct voltage on power jack.
- power button have 3.3v, so kbc has voltage from regulator. pin 11 kbc (vcc) seem active after power on and if precondition reached.

its to hard working without schematic and reference from other tech guy.

I'm a afraid to do anything (replace part), if just check voltage its not a problems, there are some risk and more damaged board

I think re-flashing bios more safety if you have Eeprom programmer. but before do it try make some work to prepare :

- download datasheet EC bios and main bios to make sure your programmer had supported
- the hard thing to do is finding whom was have that bios dump

[Herbssat]

Re: HP Pavilion 23 All In One- No power up

Thanks friend. Feels like I am reaching a dead end here. No schematic and most searches for components and datasheets have been fruitless. I have found one thing out of the ordinary or it might be reading the circuit. On the 3volt rail that powers the bios I am reading low resistance to ground about 80 ohms on a number of components. Looks like the output aluminum capacitor is tied to it.I also think I have found the 3/5 volt regulator near the bottom of the board with marking APW8822c. Looks like I may find a datasheet for it thank goodness. The biggest issue is if all the other things line up and the bios is powered by the 3va voltage, why no power at the bios chip?

[meritosari]

Re: HP Pavilion 23 All In One- No power up

As I mentioned above, experience with Quanta NZ8 and not solve the problem. the reason was I give up after checking resistance on bios chip. Weird i guess, if I put CMOS, resistance being low, but if pull out CMOS, resistance back normal.

[meritosari]

Re: HP Pavilion 23 All In One- No power up

An Update Info, someone had the bios dump.

link:
http://sualaptop365.edu.vn/threads/a...5901-a01.3527/

Reason: Same code board

you got voltage at EC spi at post#14. on main bios maybe come out after switch on first

[Herbssat]

Re: HP Pavilion 23 All In One- No power up

That's good news friend. Please give a recommendation on a good inexpensive bios programmer maybe on eBay that can handle most bios chips. Thanks for all your help.

[meritosari]

Re: HP Pavilion 23 All In One- No power up

CH341A or EZP2010

https://www.badcaps.net/forum/forumdisplay.php?f=33

[Herbssat]

Re: HP Pavilion 23 All In One- No power up

Tried to get bios file from the site listed but came back with error about needing 5 points for the action. Please advise.

[meritosari]

Re: HP Pavilion 23 All In One- No power up

here you go: