Repareer je spullen Gemeenschap Winkel

Acer entered the world of laptop computers in 1997 when it purchased Texas Instruments' mobile PC division.

1689 Vragen Bekijk alle

Opties

Acer laptop not powering on

Hi, I've got this old Acer (I think Aspire laptop) that I would like to repair. When pressing power on button it's not really responding, nothing is showing any signs of anything. So I removed all components to see if some broken part is interfering with motherboard... But it doesn't work even this way... Now, the power on button goes into the ENE KB9022Q D along with other keyboard buttons (unless I'm mistaken), so I have no idea if I'm able to turn power on without a keyboard? I can reconnect, but I'd like to try without it if possible (there are two buttons SWG1 and SWG2 which I have no idea what they are doing, and there is this CMOS marker, but I have no idea where CMOS is...?).

I want to be able to troubleshoot and at least find out what's going on as a learning experience. If I manage to repair it, even better.

I took the photo of the motherboard.

Block Image

How do I proceed? The goal is also for me to learn troubleshooting (I'm a Linux kernel dev, but I'm trying to learn more about hardware as I want to be able to repair stuff).

(This is my first post here, so please forgive me if I'm breaking some rule or something)

Thank you for your help.

Update (01/07/24)

OK, so I found where the issue is. I measured voltage on power supply and saw that there was only cca 400mV, while it should have been 19V... Then I noticed that adapter was blowing fuse... And I expected something somewhere to be shorted. So I started inspecting motherboard with a lamp and a magnifier and actually found this:

Block Image

So not much to say here, I'm not sure what blew here, was it capacitor or the IC... I will try to desolder and clean this and somehow replace faulty components. Being I have never done this before (at least not on SMD components), it will be a fun experience...

Beantwoord deze vraag Dit probleem heb ik ook

Is dit een goede vraag?

Ja Nee
Score 1
Voeg een opmerking toe

1 Antwoord

Filteren op:
Meest nuttige Nieuwste Oudste
Het nuttigste antwoord

Opties

Hi @pazuzu11198

There's no separate cmos battery. The cmos battery function is handled by the main battery. There's a lead from it that becomes the +RTCVCC battery supply i.e. Real Time Clock (aka cmos - see p.43 of the schematics linked below)

Since there's no indication of any life in the laptop you may have to start at the beginning i.e. laptops require power to work.

Here's a link to the schematics for the motherboard, model number LA-E892P that will help. (motherboard model number is seen on the board in the image that you posted)

The power on sequence is shown on p.6

Once you have the document go to p.41 to see the reference point for the +19V_VIN.

This is where the power from the charger first appears on the motherboard. If you get power at this point it proves that the charger and the laptop's DC-In jack are both OK.

Starting here because you never said whether it is powered by the battery only or not

If there's power available on the input to the board then use the search function of the document viewer you're using to view the file, to find where else the +19V_VIN reference appears e.g. on p.43 component PD301 pin 3 etc and follow the voltage to find out why the laptop is not indicating that the power is connected.

Hopefully a start. Board level repairs can take a while, especially if you don't know the history of the board to know what may have happened to it just before it failed.

Update (01/07/24)

Hi @pazuzu11198

The PU601 IC might be OK as it might just be spillover from the component next to it when it blew, so initially I would leave it alone. Just make sure that none of its pins are shorting out to each other that shouldn't be i.e. pins (2-5), (7-8 & 18) and (6,19-20) are groups of pins that do connect to each other, all the others are individual connections - see image below

Here's an image from the schematic showing the components indicated in the updated image you posted.

Once you have cleaned it up, check if PJ602 does test short circuit as this is only a jumper connector (fusable link?) and also what pin that the burned out component next to the PU601 IC connects to as this will identify it in the schematic, so that you will know what value and package size it is. e.g. PC606 is a 10U_0805_25VBK (10µF 25V capacitor in an 0805 smd package)

If it doesn't connect to the IC then you'll have to find the boardview file to try and identify it.

Block Image

(click on image)

Was dit antwoord nuttig?

Ja Nee
Score 2

3 opmerkingen:

Hi, thank you very much for answering and providing the link to schematic. I think I have a way to proceed now, and will inform of my results as soon as I get my hands on the motherboard.

Stjepan

door

Hi, thanks again. Any advice on how to properly clean this without damaging routes and nearby components?

door

@pazuzu11198

I would use a soldering iron with some solder wick (example only) to remove any excess solder from the board and also some Isopropyl Alcohol 99%+ to clean it up.

Do not apply too much heat with the iron and allow the area to cool if you have to use the iron again in the same place.

Slow and careful and gentle is the way to go.

Good luck

door

Voeg een opmerking toe

Voeg je antwoord toe

pazuzu zal eeuwig dankbaar zijn.
Weergavestatistieken:

Afgelopen 24 uren: 0

Afgelopen 7 dagen: 2

Afgelopen 30 dagen: 11

Altijd: 98