Acer chromebook R853ta-c5n6

[mazloum]

Acer chromebook R853ta-c5n6 model 2021
Hi,
A customer bring this chromebook with locked account, i programmed it with mrchromebox.tech method to install linux ubuntu,it worked nice but i got no sound, so i removed the eprom and programmed it with the original bin file..
the problem is that the chromebook can no longer powers on, i tried to program it again with mrchromebox.tech file, still no power, i checked pins solder hundred times with no success...
the charge led is green
if i press esc+refresh+power button, the charge led blinks 2 times with no display no backlight..

[mazloum]

Re: Acer chromebook R853ta-c5n6

I noticed also there is no voltages on any pin of the bios.

[mazloum]

Acer chromebook R853ta-c5n6 model 2021

Acer chromebook:
p/n= R853ta-c5n6
s/n= nxa90eb00b1901c2fe5445

Acer chromebook R853ta-c5n6 model 2021
Hi,
A customer bring this chromebook with locked account, i programmed it with mrchromebox.tech method to install linux ubuntu,it worked nice but i got no sound, so i removed the eprom and programmed it with the original bin file..
the problem is that the chromebook can no longer powers on, i tried to program it again with mrchromebox.tech file, still no power, i checked pins solder hundred times with no success...
the charge led is green
if i press esc+refresh+power button, the charge led blinks 2 times with no display no backlight. the volt at the pin 8 of bios goes to 3.3v when i insert the power supply, and after that all volts goes off at bios pins..
Can you repair the bios please
included original bios:

[SMDFlea]

Re: Acer chromebook R853ta-c5n6

bios voltage might come up after pressing the start button.Any voltage without the bios chip ? ,check if its shorted.

[mazloum]

Re: Acer chromebook R853ta-c5n6

no even without bios, the same, no volts on the pins on the board, 3.3v comes for seconds then nothing else, the chromebook was working normally, only after i erased the bios then reprogrammedit, then no power

[SMDFlea]

Re: Acer chromebook R853ta-c5n6

no even without bios, the same, no volts on the pins on the board, 3.3v comes for seconds then nothing else, the chromebook was working normally, only after i erased the bios then reprogrammedit, then no power

Check for a bios protect screw, or one of the screw mounting holes that fastens the motherboard might have a split copper trace,the screw needs to make contact with both sides.Don`t know for sure.

.

[mazloum]

Re: Acer chromebook R853ta-c5n6

For this model there is a jumper only as I read.., but it is not shorted

[mazloum]

Re: Acer chromebook R853ta-c5n6

I changed the eeprom with new one with no success

[volinakis]

Re: Acer chromebook R853ta-c5n6

I changed the eeprom with new one with no success

resolder bios chipset if you are sure you read bios properly but 1st redo soldering pads.

[mazloum]

Re: Acer chromebook R853ta-c5n6

I have a bios from another same model... I did now reprogram the bios with it, resoldered it with the same problem.... the sexond one works normal after reading its bios and resoldered it... it makes me headache...the strange thing is that it was working normally with ubuntu but without sound

[volinakis]

Re: Acer chromebook R853ta-c5n6

I have a bios from another same model... I did now reprogram the bios with it, resoldered it with the same problem.... the sexond one works normal after reading its bios and resoldered it... it makes me headache...the strange thing is that it was working normally with ubuntu but without sound

you have to clean ME(TXE) if you use bios from another laptop. Analising your "original bios" it has a lot of errors, meaning you didn't read the bios properly, that's why it doesn't start. post the bios dump from 2nd laptop.

[mazloum]

Re: Acer chromebook R853ta-c5n6

I do programmed the bios from mrchromebox, now whenever i press power button, i get 3.3 on pin 1 of the eprom then after 3-4 seconds the voltage drops to 1.8v then 3.3v again...it will make this 3 or 4 times before the voltage vanishes

[volinakis]

Re: Acer chromebook R853ta-c5n6

I do programmed the bios from mrchromebox, now whenever i press power button, i get 3.3 on pin 1 of the eprom then after 3-4 seconds the voltage drops to 1.8v then 3.3v again...it will make this 3 or 4 times before the voltage vanishes

bios chipset has power supply at pin8!!! Are you sure you didn't solder bios chipset upside down?

[mazloum]

Re: Acer chromebook R853ta-c5n6

yes pin 8 also has 3.063v , the bios is well soldered in it proper place with right direction

[volinakis]

Re: Acer chromebook R853ta-c5n6

yes pin 8 also has 3.063v , the bios is well soldered in it proper place with right direction

clean ME from the bios dump you took from other laptop and be consistent with your facts: you said you DON'T have voltages on chipset pins, now you have ...