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laptop display fault

I've got a Dell laptop (an Inspiron 9300) here with a corrupted LCD display.

Quick and awful (sorry) photo here:

formatting link

I think the display is divided up into (16 or thereabouts) vertical sections; from the left, the 1st is permanently white, the 3rd and 4th vary (sometimes flickering, sometimes several white bars as in the photo, sometimes blank), and the remaining sections have a few vertical colored lines of single-pixel width.

The display is fine via an external monitor; it's just the internal LCD display which is scrambled.

I've dismantled the lid and taken the panel out. Reseating the connector for the video feed (and wiggling the cable etc.) doesn't change anything, nor does some careful poking around of the connections between the LCD's control PCB and the LCD surface itself.

What I'm wondering is if it's worth my dismantling the bottom portion of the laptop in case there's a cabling or other fault on the main system board - or if this is clearly a case of a faulty LCD panel (and most likely in the controller IC on the panel's PCB, I'd assume)? Although the external video works and the internal doesn't, I'm not sure if that's enough of a test to indicate an LCD problem - for all I know the video path is more complicated than that and there's other stuff between the GPU and the LCD (which isn't present between the GPU and external connector).

I paid $5 for this thing, thinking I'd keep the hard disk as a spare for another slightly-older Inspiron that I still use occasionally and junk the rest, but I was surprised to find that everything seems to be working apart from the internal display; I don't know if I'd want to take the chance on buying a new panel for it, but if folk think there's a chance that the fault is in the lower section then I'll probably dismantle it further...

cheers

Jules

Reply to
Jules Richardson
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I'd say it's probably the LCD panel, but it depends on how the signal is broken out. Somebody on eBay has the video board for $20; panels are available for under $50.

It comes down to what you have the most of and what you need the most. For your $5 you have a hard drive, sell the laptop on eBay for $20 + shipping and you increase the profit and minimize the risk. Spending $50 for a panel still allows some room for profit.

PlainBill

Reply to
PlainBill

Thanks - that would be my guess too, but I just wasn't sure what [more-] modern laptops do with the video path.

I ended up taking the lower case apart (actually far less trouble than I'd expected - a far cry from the last time I needed to completely dismantle a laptop, probably ~15 years ago!). There is a daughter-board in there containing the video hardware, but reseating that board and the cable connector which feeds the LCD didn't help.

I left it running a memory test for a few hours and all seems well there, so there's not really anything else to do except decide whether to buy a replacement panel (it also needs a new battery, but I could do that after I've confirmed that the LCD is at fault), or simply use it for parts as was the original plan.

Yeah... and at least it's running, so I can always part it out (DVD drive, system board, memory, PSU) and sell those individually, which might net me a little more than selling a complete unit (where a buyer probably only wants it for one component).

I can also sit on it for a while and see if a broken (in some other way) laptop becomes available locally; my guess is that the same panel is used in a few models from a few different vendors rather than being specific to this Dell. It's not like I need to have it up and running anytime soon.

cheers

Jules

Reply to
Jules Richardson

A couple of links here might help you in that goal.

formatting link

formatting link

(anyone found other laptop LCD cross-reference pages?)

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Adrian C
Reply to
Adrian C

Interesting - that first link lists the Inspiron 9300 as having a Samsung LTN170WU-L01 or LTN170WU-L02, but the screen in this one I have is a Philips LP171WU1.

The second link doesn't mention WUXGA at all, unless that's what they're calling WXGA++?

cheers

Jules

Reply to
Jules Richardson

I would mark subparts and take pics where there is any ambiguity , taking apart. Then nothing to loose just insulated pressing of connectors/contacts and active components , powered-up, when you get down in that area.

Reply to
N_Cook

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