Dell D620 Lattitude no display

[barry wilkins]

I have had this laptop for quite sometime, it has had some use and served me well.
The reason I have hung on to it was it has got an RS232 com port ,new computers only have USB.
I have a job to do so I got it out the other day after a short while the screen went strange .there were a lot of very small images on the screen,and it went blank.
I tried connecting to an external display but no display.
I took out the hard drive and fitted to a external hard drive and I could read the drive so its OK.

So I guess the graphics card or chip has failed.

So to try and do the job I have got to do next week I will have to try and set this Acer laptop with a USB/RS232 converter so I can connect up.

Does this PC have a NVIDIA chip on the motherboard ?
After Xmas I intend to take it apart and take a look at it.

Any help or advice would be very wellcome.

Barry Wilkins

[thesloc]

Re: Dell D620 Lattitude no display

Hello Barry,

Yes, this laptop has an nVidia chip and it indeed sounds like you have a troublesome GPU. Fortunately, the solution for this exists.

In order to fix the classic "no video" symptom you will need to reflow it or reball it, which is a whole other game. Reflowing is simply heating the chip enough so that the non-leaded solder of the BGA components reflow and "re-align" themselves is temporary. Shorted solder bridges can happen under extreme temperature and cause the laptop to output no video, noisy/weird screens even after connecting them to external monitors.

Reballing -- the more permanent solution requires a stretch of skill. You will need to extract the chip and re-add solder points to the GPU and then re-attach it to the motherboard.

[ratdude747]

Re: Dell D620 Lattitude no display

Hello Barry,

Yes, this laptop has an nVidia chip and it indeed sounds like you have a troublesome GPU. Fortunately, the solution for this exists.

In order to fix the classic "no video" symptom you will need to reflow it or reball it, which is a whole other game. Reflowing is simply heating the chip enough so that the non-leaded solder of the BGA components reflow and "re-align" themselves is temporary. Shorted solder bridges can happen under extreme temperature and cause the laptop to output no video, noisy/weird screens even after connecting them to external monitors.

Reballing -- the more permanent solution requires a stretch of skill. You will need to extract the chip and re-add solder points to the GPU and then re-attach it to the motherboard.

wrong!

the issue with the NVIDIA chips in the d620/d630 is not primarily a reball issue. the chips themselves are faulty, as the underfill epoxy is defective, causing the the die to move and break the interconnects.

the only fix is a new mainboard... and if you want to go to the intel version, you will also need a new cooler (they two use different coolers since the intel version only uses 2, not 3 chips)

either that, or sell for scrap and try again... or just buy a usb to serial adapter- they work great from my use.

[thesloc]

Re: Dell D620 Lattitude no display

wrong!

the issue with the NVIDIA chips in the d620/d630 is not primarily a reball issue. the chips themselves are faulty, as the underfill epoxy is defective, causing the the die to move and break the interconnects.

the only fix is a new mainboard... and if you want to go to the intel version, you will also need a new cooler (they two use different coolers since the intel version only uses 2, not 3 chips)

either that, or sell for scrap and try again... or just buy a usb to serial adapter- they work great from my use.

Reballing the chip with leaded Sn63/Pb37 balls will take care of the "faulty" chip, which is faulty because it uses non-leaded components to begin with. D'oh! The epoxy will also come off, and there is no need to re-apply epoxy after reballing.

http://www.youtube.com/watch?v=MAFWuB12F6Y

Be sure to look up Lotfi's other videos. As you can see, reballing requires great precision of temperature (profiles) and skill. It is a bit more complicated than simply recapping.

[barry wilkins]

Re: Dell D620 Lattitude no display

Hi thanks to the replies about my faulty Dell laptop .
I watched a couple of you tube videos about heating up the nvidia chip to resolder it ,and one showing reballing of a chip assembly .
I just wondered if the solder used when the motherboard was soldered was a low melting type ( ie a bismuth alloy).
In the new year I will dismantle the computer and have a go at fixing it ,I have nothing to loose if it does not work.

Barry Wilkins

[thesloc]

Re: Dell D620 Lattitude no display

I just wondered if the solder used when the motherboard was soldered was a low melting type ( ie a bismuth alloy).

It's lead free, something like Sn96.5/ Ag3/Cu0.5 .

The melting point is about 217C, but it has nothing to do with but the incapacity of the solder to have the same properties of leaded solder.