I think the motherboard is dead

[Alison556]

Desktops are so much easier to work on. I've been in and out of the innards of this laptop like nothing on earth - and nothing is easy to access in it - my own laptop, three screws gets you into it but this one, you've to take the keyboard and everything off to get anywhere.

I know where you're coming from with the PSU but (showing my ignorance here), I thought that was onboard the motherboard and I replaced that - albeit with a manf refurbished - I guess it's not impossible for the PSU to be faulty on that too.

 

[Monkeh]

New page syndrome strikes again.

Please see the end of the last page.

 

[Alison556]

Sorry, didn't see that Monkeh.

I replaced the motherboard with a manufacturer refurbished one (a new one would have cost the same as a new lappy!!)

Our mobo was a DT781 but the refurbed one was a R872J - the supplier said it was a direct replacement and Dell had made a change to the graphics chip to resolve a known problem in the old one.

From what I read, it was Intel graphcs on the original (not sure how to find it but did a search on the model number) and it could be nVidia on the replacement.

I'm assuming that the laptop overheated big time. My niece said she was using it and it just shut itself off and never went on again. She's torture for having it on her bed or the floor and the heatsink was totally clogged up with fluff.

Edited: Just had a look. It was Intel graphics on the old one and nVidia on the refurbished one.

 

[Monkeh]

Yes, that's an nVidia GPU board you've got now. The original was Intel. A nice upgrade. Did your original heatsink cover the GPU? If not you'll have to get a new heatsink.

Replace the CPU. A T7250 just for a test (a bit slow, though) is under a fiver on eBay.

 

[Alison556]

Oooh, cheapest I found was a tenner. Will go and look again. It wont break the bank.

 

[Monkeh]

Does the heatsink look like this:

Or this:

If the former, you will need to get a new heatsink. Do not run the laptop without the correct heatsink, the GPU will die quite rapidly.

 

[Alison556]

The first one

 

[Monkeh]

The first one

Time to get a new one. Set you back a couple quid. Don't forget some new thermal material. Don't cheap out on that, buy some Ceramique. White tube, ~£3 a tube.

Make sure you lift the heatsink and check it's made good contact with the northbridge and GPU, if it doesn't, you'll need some thick pads instead.

 

[Alison556]

Thank you - I'll go and hunt for one like the second picture.

Is this it?

http://www.ebay.co.uk/itm/Dell-Lati...ther_Computing_Networking&hash=item540863bd4e

Is getting a used processor OK?

I got thermal paste. I asked for Actic MX4 but the kid told me I didn't need that and gave me CiT - no idea if it's good bad or indifferent :/

You've got me wondering if I should replace the heatsink in my own laptop (Dell E6400) as it's been getting really hot. I was going to get a cooling pad but there are so many, I've no idea what's the best make. If I'm playing a game, mine is hitting over 90 degrees

 

[Monkeh]

I got thermal paste. I asked for Actic MX4 but the kid told me I didn't need that and gave me CiT - no idea if it's good bad or indifferent :/

Honestly, there's not much between them in the real world: http://www.hardwaresecrets.com/article/Thermal-Compound-Roundup-February-2012/1490/5

The CiT stuff scares me, though, they're one of the chinese 'brands', ie 'sell the absolute cheapest ****e we can to people who know no better', I wouldn't touch it on principle. That said, it probably works fine.

You've got me wondering if I should replace the heatsink in my own laptop (Dell E6400) as it's been getting really hot. I was going to get a cooling pad but there are so many, I've no idea what's the best make. If I'm playing a game, mine is hitting over 90 degrees

Pull it out, clean it thoroughly (you can put it in the dishwasher if you really want to, I tend to put them under the tap), reinstall.

Cooling pads are mostly pointless, they cannot give you surface area, thermal mass, or better thermal conductivity, so all they do is make a noise and blow some air in the wrong places.

Is this it?

http://www.ebay.co.uk/itm/Dell-Lati...puting_Networking&hash=item540863bd4e[/QUOTE]

Yes. I see a number of them at under two pounds, though.

Is getting a used processor OK?

Well you'll have trouble finding a new one, they haven't made those in five years or so.

 

[Alison556]

I'll get the thermal paste you recommended. I'm not into Chinese stuff myself. Hindsight is marvellous - I should have insisted the kid gave me what I asked for.

After seeing the heatsink on my niece's laptop, I did take mine out - not a bit of fluff on it at all and just a tiny amount of minimal dust on the blades of the fan.

I'd seen the Coolermaster U2 - the fans are moveable to get them in the right place so wasn't sure if it was better/worse than any other. At the moment, I have a couple of pens propping the back up to give an air gap!

The reason I asked about a used processor is because this one alleges to be new

http://www.ebay.co.uk/itm/Intel-Cor...Computing_CPUs_Processors&hash=item4175231bd9

 

[Monkeh]

The reason I asked about a used processor is because this one alleges to be new

http://www.ebay.co.uk/itm/Intel-Cor...g_CPUs_Processors&hash=item4175231bd9[/QUOTE]

Old stock, maybe. Not worth the money.

http://www.ebay.co.uk/itm/INTEL-T7250-SLA49-2-00-2M-800-LAPTOP-CPU-Q3-/231269454891

 

[Alison556]

Ordered Thank you. Keep everything crossed

 

[JohnD]

Laptops are no different at all to desktops.

except, as you say, for example, the PSU which is not an easily swappable module, and that they run on an internal battery.

Or, to put it another way, they ARE different.

 

[Monkeh]

Laptops are no different at all to desktops.

except, as you say, for example, the PSU which is not an easily swappable module, and that they run on an internal battery.

Or, to put it another way, they ARE different.

No different to a desktop with a 12V input supply on the motherboard (yes, those exist). The battery is relatively immaterial. If you cannot handle a laptop, you don't know enough about desktops, either.