Need a professional help! Acer E5 does not Power on!

[Weelcup]

Hi
I have an acer aspire E5-575 laptop the is not responding to power button at all.
I have changed the KBC with new one but still same.
+3VPCU, +5VPCU... are present.. no short or hot component on board.

S5_ON signal is missing. which according to the schematics should come as soon as the power button is pressed.

I have programmed the bios …. no change
I have programmed the KBC … no change.

one thing I noticed recently is that when I remove the bios chip and connect the board to power supply, I get the S5_ON signal but also the board is not powering up and there is no power consume on the power supply.

I replaced the bios chip and reprogrammed it but no luck
I have replaced the TPS51225 that generates +3VPCU, +5VPCU but no luck.
I have replace the charging chip … because I noticed that the motherboard I identify the battery but is not charging it. however it seems that the battery was faulty.

I really get annoyed. this is the most difficult problem to identify I ever used to work on. and I will appreciate any advice.

this is its schematics.

[MJ-meo-dmt]

Re: Need a professional help! Acer E5 does not Power on!

Is the power button actually working? Is there voltage at the power button? Is the signal going to the EC?

[piernov]

Re: Need a professional help! Acer E5 does not Power on!

IT8987E has integrated ROM. May or may not be reprogrammed automatically from BIOS if blank on first power on.
If you have an EC programmer flash it manually.
When on AC adapter usually S5 rails are present without pressing power button. Not sure here since it's not written in the schematics.

Check all the power rails going to the EC.
Check the EC reset line WRST# , it's delayed from +3V_LDO_EC so make sure the components are good.

Also check if S5_ON is at least slightly pulsing when plugging in AC adapter.

[khaahk]

Re: Need a professional help! Acer E5 does not Power on!

Also might be good to check S5_on resistance to gnd. It may be pulled low by any of the lines it is connected to. (alathough if it is high when no bios chip present it should not be the case)
Check #lid signal on ec.
Check for Y2 clock 32khz presence.
Where did you get the ec dump to program? Did you save the old one? Are they same?

[Weelcup]

Re: Need a professional help! Acer E5 does not Power on!

Is the power button actually working? Is there voltage at the power button? Is the signal going to the EC?

Apologies for being late.
Yes there is 3.18v at the power button. And I tested the power button. The power button is fully working but nothing happen when pressed.

[Weelcup]

Re: Need a professional help! Acer E5 does not Power on!

IT8987E has integrated ROM. May or may not be reprogrammed automatically from BIOS if blank on first power on.
If you have an EC programmer flash it manually.
When on AC adapter usually S5 rails are present without pressing power button. Not sure here since it's not written in the schematics.

Check all the power rails going to the EC.
Check the EC reset line WRST# , it's delayed from +3V_LDO_EC so make sure the components are good.

Also check if S5_ON is at least slightly pulsing when plugging in AC adapter.

Thanks for the reply.
Yes there is a plus at s5 pin when ac is plugged.
If I am not mistaken, the schematic referING to s5_on signal to be present in step 8 just after the power button (step 7 )... but I am not sure I'd it refers to pressed power button.
I will check WRST# Signal and come back to you today...

Thanks a lot.

[Weelcup]

Re: Need a professional help! Acer E5 does not Power on!

Also might be good to check S5_on resistance to gnd. It may be pulled low by any of the lines it is connected to. (alathough if it is high when no bios chip present it should not be the case)
Check #lid signal on ec.
Check for Y2 clock 32khz presence.
Where did you get the ec dump to program? Did you save the old one? Are they same?

Thanks for the reply...
I have my dumped EC and bios.
I also download a dumped EC and Bios online. They doest match exactly but they are for the same board.
I don't know if this make sense but I could only read the ec chip when the bios chip is attached to the board .. even though all the voltage are present in the ec chip.

[ktmmotocross]

Re: Need a professional help! Acer E5 does not Power on!

Apologies for being late.
Yes there is 3.18v at the power button. And I tested the power button. The power button is fully working but nothing happen when pressed.

fully working means that he shorted that line when u press it?

[on/off]

Re: Need a professional help! Acer E5 does not Power on!

Also make sure there R741 and have good value resistant.

[Weelcup]

Re: Need a professional help! Acer E5 does not Power on!

fully working means that he shorted that line when u press it?

yes that is exactly what I meant...

[Weelcup]

Re: Need a professional help! Acer E5 does not Power on!

Also might be good to check S5_on resistance to gnd. It may be pulled low by any of the lines it is connected to. (alathough if it is high when no bios chip present it should not be the case)
Check #lid signal on ec.
Check for Y2 clock 32khz presence.
Where did you get the ec dump to program? Did you save the old one? Are they same?

hi again,
I don't have the oscilloscope to test for the 32khz. but on the multimeter hz=50hz... I don't know if that helps..

however, I only get 3mv on LID# on both sides of R260.
the S5 resistance to grd = 40K. so no short.

[Weelcup]

Re: Need a professional help! Acer E5 does not Power on!

also make sure there r741 and have good value resistant.

r471 = 9.83k

[khaahk]

Re: Need a professional help! Acer E5 does not Power on!

however, I only get 3mv on LID# on both sides of R260.

Lid should be high, that might be your problem.
However it is unclear how it is pulled high, there is a mention about internal pullup (from EC), so is R53 present?
LID# resistance to gnd?

[ktmmotocross]

Re: Need a professional help! Acer E5 does not Power on!

on power switch should be 3.3V

[Weelcup]

Re: Need a professional help! Acer E5 does not Power on!

on power switch should be 3.3V

the switch is ok and it does short the 3.3v to grd when pressed.

[Weelcup]

Re: Need a professional help! Acer E5 does not Power on!

Lid should be high, that might be your problem.
However it is unclear how it is pulled high, there is a mention about internal pullup (from EC), so is R53 present?
LID# resistance to gnd?

R53 is not present. I mean the resistor itself is not soldered to the board.
BL# is 3.3v but BL_ON is 0v...

LID# to GND is 6.7M.... no short at all


just 2 questions...
1- now I have 3.3v on the MR1 pin1 but I don't have output at pin2! is that OK?...
2- also SYS_SHDN# is high 3.3v shouldn't that be 0v in order for the system to power up?



thanks

[on/off]

Re: Need a professional help! Acer E5 does not Power on!

just 2 questions...
1- now I have 3.3v on the MR1 pin1 but I don't have output at pin2! is that OK?...
2- also SYS_SHDN# is high 3.3v shouldn't that be 0v in order for the system to power up?



thanks

1. So MR1 need to replace, input present but no output.
2. in old schematics of quanta should be approx 5V-6V (usually getting from resistor divider from VIN). but for this series i think is fine, since you have NBSWON# signal.

AH9249NTR

[Weelcup]

Re: Need a professional help! Acer E5 does not Power on!

1. So MR1 need to replace, input present but no output.
2. in old schematics of quanta should be approx 5V-6V (usually getting from resistor divider from VIN). but for this series i think is fine, since you have NBSWON# signal.

AH9249NTR

this was a precious reply. thanks a lot. at least we found a faulty element which is mr1... I don't have its replacement are there any alternatives. I am not good at finding alternatives ...

[Weelcup]

Re: Need a professional help! Acer E5 does not Power on!

1. So MR1 need to replace, input present but no output.
2. in old schematics of quanta should be approx 5V-6V (usually getting from resistor divider from VIN). but for this series i think is fine, since you have NBSWON# signal.

AH9249NTR

Lid should be high, that might be your problem.
However it is unclear how it is pulled high, there is a mention about internal pullup (from EC), so is R53 present?
LID# resistance to gnd?

khaahk & on/off you both guys were right. I shorted mr1 source and gate pins and olaaaa I have a fully working laptop...

I just need to order AH9249 from china and be patient until receive it. and off course replace its main battery as it. the battery cells are ok but it does have a faulty battery board. it might be the cause to brick MR1 but not sure.

However, all the thanks to you guys who advised me until we get it fixed.. thanks a 100000000000000000000 million

[budm]

Re: Need a professional help! Acer E5 does not Power on!

So is MR1 AH9249?