HP LA-E801P power off after few sec

[mferna14]

Re: HP LA-E801P power off after few sec

Thanks all., I physically removed TPS51225C (which was also getting hot) Injected 3 volts on VREG3, & KBC KB9022Q gets hot.. Similar problem was with the other board too. I replaced the KB9022Q but still the new chip was getting hot. I think the problem lies somewhere else. The only difference was when I removed KB9022Q I checked the resistance on the Caps & it was normal NOT 2 ohms, but when I soldered KB9022Q back again the caps again showed 2 ohms resistance. Something within this circuit is faulty which cannot figure. Hope I get a Schematic to check when about this circuit leads too.

[mcplslg123]

Re: HP LA-E801P power off after few sec

Remove the kbc again, clean the pads and re-measure resistance on VREG3. Still put 3V on vreg3 from bench psu and see the consumption and what is getting hot. Most likely PCH part of SOC will heat up.
PS:You can apply power safely without kbc.

[emestee]

Re: HP LA-E801P power off after few sec

LA-706p is supposedly the closest model.

[classicandy]

Re: HP LA-E801P power off after few sec

Remove the kbc again, clean the pads and re-measure resistance on VREG3. Still put 3V on vreg3 from bench psu and see the consumption and what is getting hot. Most likely PCH part of SOC will heat up.
PS:You can apply power safely without kbc.

If PCH part of SOC heats up, does that mean PCH is faulty? Or it's possible for SOC to heat up (maybe a little) and still not be faulty?

[emestee]

Re: HP LA-E801P power off after few sec

Inject 3V on VREG3, burn your finger on the PCH, cry.

FYI this is a timeless classic now.

[mcplslg123]

Re: HP LA-E801P power off after few sec

If PCH part of SOC heats up, does that mean PCH is faulty? Or it's possible for SOC to heat up (maybe a little) and still not be faulty?

Could be yes but most often its the faulty PCH, If PCH is heating up. In some rare cases you may find a cap on the back of pch faulty or a cap shorted in RTC area of pch but those cases we come across very rarely. 99% of the times its pch itself being bad. If the board comes from earlier service, i do check that first as very often pch is damaged by service attempt by people without much skills and knowledge.

[mferna14]

Re: HP LA-E801P power off after few sec

I cannot believe, same problem in both board, but in this one KB9022Q was shorted but in the other one there is something else wrong. Programmed the chip & all works fine.... Thanks for all the help.. (:-