Laptop won't "light up"

[chickenbeef]

Okay, firstly if you don't have much experience with laptops go find another thread to post in.

I've got a Dell D820 Laptop, the problem I'm experiencing is that it does not switch on at ALL. I don't mean POST or load Windows, it's as if it's not receiving any power. Normally when plugged into the mains it would light up to indicate the battery being charged/the current power source would be AC. However, now it just seems dead.

What I've done so far:

1. Tested the power adapter with a multimeter, there is in fact power being supplied to the laptop at the rated specs

2. Cleared the CMOS (1 in a million shot)

3. Opened it, checked for any blown fuses/burn marks and there's nothing. No fuses, no burn marks

4. Reseated the memory and CPU

After all that it's still dead.

So my questions are

Could it be the motherboard that's the problem? I know with desktops, without a CPU and Memory they would atleast light up to indicate that they're receiving power however here everything is just...dead. Unfortunately I don't have another CPU to test in it.

The laptop is out of warranty, is there a Dell service centre or something which I can send it to or where can I get a motherboard for it locally (if that's the cause)?

 

[Jola]

Have you tried starting it without the battery installed ?

I have seen cases where the battery has failed so badly that it prevents the laptop from starting up.

CPU's don't often fail, but I would swap the memory out if you can get some - or try with one stick at a time (if you have two).

Does your D820 use the T2500 CPU ? I see that people upgrade it to the T7200, I have one of those (but haven't decided to sell it yet).

 

[chickenbeef]

It has a T7200 installed. Yep, I have tried turning it on without the battery but still nothing (bought a new battery for it at the beginning of the year). No lights go on, nada. Not even the fan spins.

 

[chickenbeef]

Think I found the problem. Will post back if i can get it stable

 

[scotty777]

ok, maybe have you checked that there's power actually going to the motherboard... It's unlikely given the wattage, but a moth, or dust could have shorted out the power terminals on the mobo... if so, you might be able to just re-solder them on . Take the whole thing apart, and check the power cables (from battery/power supply to the mobo).

In any case, visible damage only happens when there's a lot of power running in the circuit, unless there's a bad shortcircuit somewhere... so you might not be able to see the things burnt out, but they are pretty well stuffed... I've seen destroyed capacitors which look normal, but pretty much do nothing .

Um, also, don't deny the battery! Manufacturing imperfections happen a lot, and all it takes it a little bit of a short circuit and each cell slowly gets more and more stuffed, or it could just stop working all together.

However, this may also come down to a stuffed motherboard where by the bios chip is buggered, and it just won't even allow a boot (very unlikely though).

 

[howardb]

Try and remove the battery and the power pack, press the power button for 10-15 seconds, then reconnect the powerpack only and try and switch on.
Is the CPU fan clogged up at all?

 

[stroebs]

This doesn't look good. Last time this happened to me with a Dell system, the motherboard had packed in. I recommend you do what scotty said and take the whole thing apart and look for something that is broken

 

[chickenbeef]

Thanks for the replies guys. Managed to sort it out this morning.

To check if ANY power was running through it I plugged it into the mains without the battery and the CMOS battery. I then tested the connections for the CMOS battery with my multimeter to see if there was electricity flowing through the board and there was none (the mobo should charge the CMOS battery and thus, it should give a reading on the MM).

After poking finger everywhere found that the port on the mobo to connect the AC adapter to the laptop was not making proper contact so took that out and soldered it on again. This time I got the lights to come on but no post, so took some sandpaper add very lightly sanded the connectors so they make proper contact (to get rid of any build up). Put it back together and it's working.

 

[ponder]

After poking finger everywhere found that the port on the mobo to connect the AC adapter to the laptop was not making proper contact so took that out and soldered it on again.

Very common problem that on laptops, with time the DC socket works lose.