LCD Screen Problems with Latitude CPi

Question

I'm working on a rather old Latitude CPi. It developed a problem with the LCD screen; at narrow angles (and even eventually straight up), the screen was completely black. It would flicker while being tilted. I thought perhaps its cable had become loose, so I opened the case to reseat it on the board. This done, the screen would no longer turn on at all. The system powered on just fine, but nothing on the screen. I could not make anything happen at all. I acquired anothter screen which has been tested and found to work. And this is where it gets really interesting. Plugged the screen into the board, then plugged power into the laptop (no battery in). No change. Press power. Nothing happens. Without unplugging power, unplug the screen -- and the system powers up. Turn the system back off, unplug power, plug in LCD cable, plug in power -- LED D3, which indicates power and has an icon of a battery on the system's case, begins blinking between green and red very quickly. Pressing the power button stops this. Unplug LCD cable, system powers up. Turn it off, unplug power. Plug in LCD cable. Plug in power. LED D3 blinking again, this time three flashes of green then one of red. Power button does not stop this but system will not boot. Unplug LCD cable, system boots spontaneously. Another repetition of the same procedure gets me a repeated series of green flashes. A slight change; the power button does not stop the flashes. Unplugging the video cable does but no longer spontaneously boots the system. It seems to have settled into this. To clarify my terminology and work procedure: I am working on the system with the keyboard and cover removed, obviously, so as to have access to the board. When I say 'LCD cable' -- a black spool or cylinder extends to the right from the left protrusion at the bottom of the screen casing. A black ribbon/cable with visible copper-looking surface is partially wrapped around this; the cable terminates in a large plastic piece, male in configuration, with inset small wires. It's a sort of plug, and it fits into a receptacle on a board in the computer. This board is the topmost board of any significance visible upon opening the system; it bears a MagicMedia chip of some sort and I infer it to be a video board, although I am not certain of this. Putting the male end of the ribbon into its socket on the 'video board' is the act I refer to as 'plugging in the LCD cable.' I have not examined the LCD screen itself to any extent becaue I have never worked with them and have no access to materials on the subject. I have the impression that the casing simply snaps off, but don't know this for sure. One other thing of note: The socket on the 'video boaord' is female. Besides the area to receive the LCD cable on the inside, it has thin pieces of a silver-colored metal on each side, roughly the height and width of the socket itself and extremely close to thte edges of the plastic. The one closer to thte back of the computer was bent slightly toward the back of the computer, whereas the frontward one stood straight up. Straightening the one toward the back produced no effect. I don't care which LCD screen works in the end, I just want one of them to. I'd assume the problem was in the board, except the fact that the newly-acquired LCD screen causes all those weird LED things demonstrates that there is a difference of some sort between the screens and gives me hope. Any advice? -Paul

stevecotton · Answer

I have a latitude cpi r400, asumed to be the same as yours. I too had the problem with the lcd screen, yet instead of replacing the screen i had one of my IT buddies find a compatible video card and replace it. The magicvideo or magicmedia chip is the VIDEO board, and i believe they are 4mb agp video cards. Fortunately for me the friend of mine founda copy of the same video card and simply replaced it, no upgrade simply for the fact that i dunno what kind of new card would be compatible or even wortht eh cost for a pentium II processor.I cant do much becasue the processor is slow and old so gaming, dvds, and most other "modern media" i cant use the laptop for, i sheerly use it only for work. My suggestion, replace the video card sounds like it would do the trick. these laptops being older tend to run hot, mine gets really hot, so uch so that i cant keep it in my lap and must keep it on a table to work with. I believe the heat that the card and moterboard are exposed to can tend to shorten the life span of them and therefore may eed replacing. Quite frankly i have given up on my outdated piece of pentium II cpi 400 poop. I about to get a new notebook, but i hope the suggestion helped, although i not sure if my blabbering did.

steve

AussieChris · Answer

Hi,

You may have a damaged flex cable. It may be shorting the power. The other part that may be bad is the invertor. ( you could unplug the flex cable from it to see if it will boot ) A failed one will stop the machine booting, but would be unrelated to changing the screen. Have a good look at the cable, and if it looks damaged replace it. Changing the LCD may have caused some damage to it. It may also be worth reseating the CPU and video card, unrelated but often cause issues with your model.

Regards Chris

paulbee · Answer

Is there any leeway on compatible inverter boards that do not have the original part number? My inverter board is a 7719R, which is listed on hard-to-find parts websites and seems to run over $50. I find inverter boards that look identical yet are different part numbers on eBay for $5-$10. Is using one of them a possibility?

-Paul

Locked Topics – Laptops General

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