Laptop won't power up with AC adapter and won't charge battery

[pepi93]

1) the laptop doesn't power on without a battery
2) the light which would indicate that the laptop is plugged into the ac adapter is not on when the ac adapter is plugged in.
3) the battery charge light is also not on, which would indicate the battery is being charged.

The battery does not charge...
The AC adapter is fine, tested with other laptop.
The battery is also new and works fine

I took the laptop apart. Took out the DC Jack and tested it separately.

I used a crappy non digital volt meter. Set it to 50 DC V. Plugged the DC Jack into the AC adapter...

There are 2 red 2 black. Each red shows 8V exactly.

I plugged the dc jack into the motherboard with the AC adapter connected, with the motherboard out and proceeded to test the various contact points on the 4 pin connector with the dc jack plugged in. I tested contact points on both sides of the motherboard on the soldering points. Each time getting the 8V reading.

Thanks for the help

 

[pepi93]

found it but there's no way I can read that...any other indicator that could work?

 

[jarotech]

Ok, a bigger one is the U6000 24 pins chip.

 

[pepi93]

17453se tg(or q)d43 itbi +

 

[nforce4max]

This board is likely shot and when a high priority chip like this fails it usually takes others with it unless there is a bad joint you are not likely to get this running. So you are left with one other option and that is to hunt down another board. I rebuild and customize laptops so I learned what to fix and what to flat out avoid. When a board goes out it is usually not worth the money fixing or replacing but bad chips can be difficult to root out.

 

[pepi93]

the board and laptop work fine on battery so it must be a very local issue. I don't believe I can start soldering on new parts of the motherboard but I'd like to know what exactly is blown.

 

[jarotech]

Ok give me the voltage on the R6013 resistor, it's below 2V DC.
On one side is zero volt.

 

[pepi93]

if it's a tiny little one then it gave me no readings and I have no idea what you mean by "below 2v dc"

in any case, if I got the correct resistor, it gave me no readings no matter where I touched it.

 

[jarotech]

I said it's below 2v DC because you need to have a low scale on the voltmeter to have an accurate reading.
You have the coil L6001, what do you have on both side.

 

[pepi93]

I had the volt meter set on 10vDC for the others....for L6001 it's about 19-20v on both sides.

 

[jarotech]

Now the MOSFET Q6002, pins 5,6,7,8 all connected together for the drain, pins 1,2,3 all connected together for the source, and pin 4 for the gate.
What are those voltages, drain, source and gate.

 

[pepi93]

1,2,3,4 19-20v
5,6,7,8 about 3v....the top pin (I'm assuming pin 5) on the right side if I'm looking at the Q6002 right side up doesn't have any power
the other 3 on the right side I'm assuming 6,7,8 are all about 3v

 

[pepi93]

I'm just thinking, I don't understand how it's possible that the entire system works fine on battery but won't charge and won't power up on the ac adapter...

 

[jarotech]

Hi, I'm back, it's because you have the charging circuit (MAX17435ETG) who switch between the adapter and the battery. It's some component around this chip or the chip itself who is the problem.

 

[pepi93]

can we fix it?

 

[jarotech]

I can do it, but you if you never solder before I don't think so. You need to have the skill in soldering to do a good job. You must have a soldering iron and a hot air soldering iron to remove the chip. The most difficult component is the chip (MAX17435ETG) if it's the problem. And you need to find the component also.

 

[pepi93]

So based on the troubleshooting we did, you can confirm that it's that one chip? Where would I find it on the board? Maybe I can find a guy locally to do it...do you think the job would be costly?

Can I test this chip via the volt meter to confirm it's dead?

 

[jarotech]

The voltages you gave me are not conclusive to determine for sure that U6000 is defective. To be sure, give me the voltages for the :
D6004 diode = ?
D6005 diode = ?
R6012 resistor on both side = ? and = ?
C6023 capacitor = ?
C6032 capacitor on both side = ? and = ?
all those voltages referring to ground or black wire.

 

[pepi93]

ok ill do this later, I really need to get a magnifying glass.

thanks again.

 

[jarotech]

Those components should be around the U6000, it's somewhere to start, and they are very small.

 

[pepi93]

Sorry it took so long, got busy at work...

D6004 - 19v
D6005 - 19v
R6012 - can't find for the life of me, I have a 16 and a 13 but no 12
C6023 - 19v
C6032 - 3v-0v