HP motherboard 3Volts overheating - hp 14-bp019nf

[fab13]

Hello,

I have a motherboard from an HP that does not start.
This is a GLA-6L and when connecting the mains which is ok and after checking with the thermal camera shows that the 3volts chip (SY8286BRAC) at more than 100 degrees very quickly which is abnormal and no short circuit on the line after verification.

Since aliexpress sells a SY8286A chip which is equivalent so I changed the chip for the second time and still the same problem.
You can see on the boardview that it is the PU10 chip as well as in the diagram.
I did not inject current on this 3 volts line.

I don't understand what is wrong, is it a resistor out of order? What should I do?
Complete diagram of the motherboard.

I will be happy to be able to find this functional pc = D

And ready to answer any questions.

thank you very much

[mon2]

Re: HP motherboard 3Volts overheating - hp 14-bp019nf

What is the suffix of the original part?

The suffix of the replacement is not the same as the original. There are variations to these parts defined by the suffix in the part number.

[fab13]

Re: HP motherboard 3Volts overheating - hp 14-bp019nf

Hello, thank you for the response
This was the SY8286BRAC chip and I replaced with a SY8286A on aliexpress

Could this be the wrong chip model?

[mon2]

Re: HP motherboard 3Volts overheating - hp 14-bp019nf

Yes, I think so. According to the internet, the following part from TI is a drop in replacement for the original:

TPS51285BRUKR

See the attached datasheet. Respectively, note the difference between the 'A' and 'B' versions. This could be the fault for your replacement part as well.

The TI datasheet can be used to determine the details of this IC.

Respectively, the TI part is rare as the dodo bird so best to go check on Aliexpress for the original part with the proper suffix or order the above TI component from Asia.

Win-Source is claiming they have the TI part in stock but they are charging an arm and a leg for the device. They used to be a nice company to work with but no longer.

[fab13]

Re: HP motherboard 3Volts overheating - hp 14-bp019nf

Thank you so much for the answer, because I had so many questions, did I weld well and so on... but yes.

So the problem seems to be the wrong reference and I placed a SY8286A necessarily =S

But one thing I do not understand on the datasheet of the TPS51285A or B does not seem to correspond to the diagrams and there are not 4 lines (pads 2,3,4,5) +VIN contrary to the SY8286BRAC chip (See boardview).
On the TPS51285A/B there is pad 12 which has the VIN.

Normally I should have the same thing no?
Is it possible to replace with a SY8286B found on aliexpress?
If not, which TPS51285A or TPS51285B chip to install?

Thanks again =D

Translated with www.DeepL.com/Translator (free version)

[mon2]

Re: HP motherboard 3Volts overheating - hp 14-bp019nf

I see your point. Let me study it with a clear focus but will advise to hunt down the SY8286B part from Aliexpress. Confirm with the vendor that you can cross this part for your original. With the 'B' suffix, you should be ok and believe it means that 2 LDO rails are fixed on (3v3 & 5v0).

[mcplslg123]

Re: HP motherboard 3Volts overheating - hp 14-bp019nf

SY8286BRAC & TPS51285 is completely different IC.

[fab13]

Re: HP motherboard 3Volts overheating - hp 14-bp019nf

And yet the SY8682BRAC corresponds to the diagram of my motherboard. So which one to choose? Can I try to order and try the SY8286B (Waiting time 2 weeks to 3). The TPS51285A chip looks totally different on the rails. I'm a little lost ^^ and thank you for your feedback in advance

[mon2]

Re: HP motherboard 3Volts overheating - hp 14-bp019nf

Skip the TI. Use the original part that you see on the logic board & schematic. Someone on Aliexpress should offer the exact replacement. The TI part is 'functional' equivalent so if someone was to redesign for the same purpose, they could do so with similar features not the same pinout. The cross statement on the internet is quite vague and should not be posted.

Summary: The part that is on your logic board is SY8682BRAC ?

[fab13]

Re: HP motherboard 3Volts overheating - hp 14-bp019nf

Okay, I didn't know his information that a different manufacturer can possibly build with the same functionalities but not with the same pinouts. Have learned about it every day. So not really relying on the same pinouts? The original chip is indeed a SY8682BRAC yes and ordered supposedly the same on alixpress. I will update in a few weeks to check if this new reference works. In any case, big big thank you for all the very constructive and explanatory information.

=D =D

[SERGEY1962]

Re: HP motherboard 3Volts overheating - hp 14-bp019nf

This is a GLA-6L and when connecting the mains which is ok and after checking with the thermal camera shows that the 3volts chip (SY8286BRAC) at more than 100 degrees very quickly which is abnormal and no short circuit on the line after verification.

Since aliexpress sells a SY8286A chip which is equivalent so I changed the chip for the second time and still the same problem.

You probably have an LDO pin 17 shorted to ground by one of the bunch of components connected to that +3VPCU power rails, most likely this will be EC (IT8987). Measure the resistance to ground on +3VPCU LDO output pin 17 of SY8286B, and if it's low in Ohms, perform a short test on this pin. Read this trainings as it contains a lot of knowledge and helps to understand how to do the short test and what to expect https://www.elvikom.pl/szkolenie-nr-...opow-t986.html

SY8286A is NOT an equivalent of SY8286B since entirely different functions of pins 11-15 between them. There is no known equivalent for SY8286B so you must use the original SY8286BRAC chip.