Toshiba laptop display problems

[SimonH]

Long shot, but hope someone can help, bearing in mind my business is repairing desktops. My Toshiba laptop has been playing up lately, turning it on, the screen shows a backlight but nothing else, just black. If I turn it off and on again enough times I can usually get it working, but then it goes again when I next turn it off. I'm suspecting a wiring problem somewhere but don't fancy taking off all those screws on the bottom just yet. Any ideas ? I'm stumped

[grotbag]

We used to have a similar problem on a set of Samson V20's which we ended up replacing with the V25.

They would go 'bar code' or 'blank'. We originally thought it was because of the narrow screen surround and the quantity of file we put in the lappy bag.

Turned out to be a wiring problem, through the 'hinges' which connected the base to the lid on the V20's - a design fault. The V25's have a separate hinge type thingy where the wires go from base to screen.

Could your problem be similar?

Have you searched the web for similar problems?

[SimonH]

Sounds likely GB, I've searched the internet to death on this one. The screen part of these laptops is pretty flaky, the backing cracked around the hinges aome time ago. Looks like I may have to dismantle it to have a look. It's a couple of years old now, so maybe it's time to upgrade anyway.

I think Toshina got the design wrong on these, 17 inch widescreen monitor with a tiny hinge at each end, nothing in the middle for support.

Ta for the reply

Si

[FirestormMike]

Vickies laptop does the same, have to wiggle it backwards and forwards to get it to come on sometimes.

[Rerb]

Three things it could be:-
1 The back light bulb (complete pain to replace)
2 the invertor (powers the back light bulb)
3 Dodgy cable (betwixed screen and main housing)

[SimonH]

Cheers Rerb. any idea how I get to the invertor, I've seen a couple of posts on the web referring to this, but no idea what it is, having said that, I suspect cabling is the most likely.

[bigmax]

If the screen is just showing white, it's not going to be the back light, it would just be black if that failed. It sounds like either the graphics card has gone or more likely the cable that goes thru the hinge. They're made of mylar with the copper track inside and go brittle then fail.

The inverter and back light are so expensive they're not worth repairing anyway

Edit: just re-read the first post, is it showing a backlight or is the screen black/blank?

[SimonH]

Originally Posted by bigmax

Edit: just re-read the first post, is it showing a backlight or is the screen black/blank?

I can see a faint backlight, but the screen is black, well, grey with the backlight on. Interestingly, I've discovered today that removing the battery completely and just plugging in mains power, it seems to come on every time. For the life of me I can't understand the link between the two ??

[Rerb]

Originally Posted by SimonH

I can see a faint backlight, but the screen is black, well, grey with the backlight on. Interestingly, I've discovered today that removing the battery completely and just plugging in mains power, it seems to come on every time. For the life of me I can't understand the link between the two ??

Do you mean this problem happens when the battery is the only power source?

[SimonH]

Originally Posted by Rerb

Do you mean this problem happens when the battery is the only power source?

Problem happens either when the battery is the only power source, or when the battery is installed, but mains power also attached. Seems to disappear when on mains power only, with the battery physically removed. That said, if I boot it up on mains power only, then insert the battery, it's fine until the next reboot. How peculiar.