HP 15-ac126nv no power at all

[harshana]

Re: HP 15-ac126nv no power at all

I tried it no change, still getting onlily 0.0011A and resistance 1.7kΩ

you are facing strange things. I have no idea how its possible. anyway have you cleaned all liquid damaged areas with alcohol?? If not first clean the board. Then lets try to start again.

Edit: If you can heat the board using hotgun I guess some solder points will make a good connection.

[Andreasbest]

Re: HP 15-ac126nv no power at all

Strange things indeed, somebody told me that might be capacitor ready to die.
Yes all damaged area is cleaned with isopropylene alcohol

[harshana]

Re: HP 15-ac126nv no power at all

Strange things indeed, somebody told me that might be capacitor ready to die.
Yes all damaged area is cleaned with isopropylene alcohol

as I know capacitors should heat up if they defective. Can you heat the board. To make good connection on solder points

After that, check resistance on PU2 all the pins. If the resistance are okay, sold pu2 and pq7 back and check. I Dont think 1.7kohms allow PU2 to heat up. (according to the calcuations)

[Andreasbest]

Re: HP 15-ac126nv no power at all

Not gonna put the mb to over or resolder everything, not worth the time.
Any other idea?

[mcplslg123]

Re: HP 15-ac126nv no power at all

LDO3 resistance at 1.7K is too low. have you removed the KBC??

Btw, what is the resistance on PL12 coil??

[harshana]

Re: HP 15-ac126nv no power at all

Not gonna put the mb to over or resolder everything, not worth the time.
Any other idea?

I suggested it because I see resistance keep changing. May be contact issues. anyway, then we will have to test all the endpoints who use +3VL

I saw you have mentioned that you removed a capacitor. Who was that?? Can you remove PC46 (marked in the image) and test resistance again on pin 15.

Anything changed??

[Andreasbest]

Re: HP 15-ac126nv no power at all

No KBC not removed, only PU2 and PQ7, i'll check resistance Monday because i'm again away from the bench and let you know.


I only removed the capacitor next to pin15 of PU2 but it's working fine, not shorted.
I'll try PC46 on Monday and let you know.

[Andreasbest]

Re: HP 15-ac126nv no power at all

Hello!
Finally found some time to remove KBC.
Now resistance @ pin 15 of PU2 is 45ΚΩ and raising.
KBC is dead too?

[mcplslg123]

Re: HP 15-ac126nv no power at all

Hello!
Finally found some time to remove KBC.
Now resistance @ pin 15 of PU2 is 45ΚΩ and raising.
KBC is dead too?

Do i need to confirm that kbc is dead.

[Andreasbest]

Re: HP 15-ac126nv no power at all

So KBC needs programming as you told me so the motherboard goes to donor, can you confirm this at least

[harshana]

Re: HP 15-ac126nv no power at all

So KBC needs programming as you told me so the motherboard goes to donor, can you confirm this at least

you will be able to find programmed chip. So I suggest to replace KBC.

PS: If you have time,I guess you will be able to use Raspberry or arduino to program KBC. Just an idea. still had no chance to try.

[mcplslg123]

Re: HP 15-ac126nv no power at all

KB series sio used on this mb is definitely programmable and there are pre-programmed chips available in market. So give it a try or else take it to someone who has the tools. KBC programmer is a must if you earn money from this business as almost all the mb has programmable kbc chips these days. I dont know whether raspberry/arduino can program kbc but i think its not possible.

[harshana]

Re: HP 15-ac126nv no power at all

KB series sio used on this mb is definitely programmable and there are pre-programmed chips available in market. So give it a try or else take it to someone who has the tools. KBC programmer is a must if you earn money from this business as almost all the mb has programmable kbc chips these days. I dont know whether raspberry/arduino can program kbc but i think its not possible.

Here is the guide I found from youtube. He use CH431a programmer to program KBC.

https://youtu.be/GQGH6yZuXCc

I was able to flash lot of bios chips using Raspberry pi 3. the software I used was flashrom. Anyway I guess we can use same method to flash KBC.

I can guarantee Its possible to flash Bios Chip using Raspberry pi

[Andreasbest]

Re: HP 15-ac126nv no power at all

I have CH431A but i have some questions:
A) Where do you get the dump)
B) How will i identify a already programmed and a nulled one?
On ebay i only see the KBC chips, none mentions "preprogrammed" etc.

[Andreasbest]

Re: HP 15-ac126nv no power at all

[deleted]

[harshana]

Re: HP 15-ac126nv no power at all

I have CH431A but i have some questions:
A) Where do you get the dump)
B) How will i identify a already programmed and a nulled one?
On ebay i only see the KBC chips, none mentions "preprogrammed" etc.

A) You can find them from internet. try to request dump from the bios section of this forum.

B) I see pre programmed chip on Ebay. Mention the KBC No. I will try to share a link

[SMDFlea]

Re: HP 15-ac126nv no power at all

NeoProgrammer software for the CH341A .Its better to invest in a proper IO programmer though, as mcplslg123 said "KBC programmer is a must if you earn money from this business as almost all the mb has programmable kbc chips these days."
.

[harshana]

Re: HP 15-ac126nv no power at all

https://www.ebay.com/itm/20290393339...mis&media=COPY

see. you can find the chip if you search

[Andreasbest]

Re: HP 15-ac126nv no power at all

Ok so to summarize: i need PU2, PQ7 and a new KBC, correct?

[Andreasbest]

Re: HP 15-ac126nv no power at all

https://www.ebay.com/itm/20290393339...mis&media=COPY

see. you can find the chip if you search

Ok so i must search for programmed chip for this particular mb, thank you for the info