need help with m45-s351 backlight please

I'm having trouble with the backlight on my m45-s351 notebook. When I first turn the notebook on I can see an image on the screen for a second or two before the screen goes blank. I'm able to use an external monitor with no problem and if I shine a light on the laptop's LCD I can see images on the screen - this leads me to believe it's just a backlight problem. Is there any way for me to further troubleshoot this to determine what the exact problem is? If it's something I can diagnose and fix myself I would prefer to do that instead of taking it to a local computer shop (the computer is obviously out of warranty).

I did a search and I see a lot of people mention the inverter but how do I know if that's my problem? Any help is greatly appreciated.

 

There are a few things it could be. The lamp itself, the inverter that powers it, or the cabling to both. Cabling is often a simple first solution to try. You'd want to get disassembly instructions for your model and determine where the ribbon cable is that connects the motherboard to the LCD, then remove and reseat the connection at both ends. Also check the connection from the lamp to the inverter. You should also be examining the cables for crimps or exposed wires or anything that would suggest the wire isn't making good contact or has been damaged. Test the laptop to see if that resolves the problem.

If it doesn't, I'd look at the inverter to see if it has any obvious serial numbers or markings, then try to price a replacement. Replacing the inverter is normally a lot easier than replacing the lamp, so it's a good next step. If you're confident with electronics and are familiar with safely dealing with electricity you could test the inverter with a multimeter to determine if it is still sending power to the lamp. If it is, you'd want to price a lamp bulb and gingerly work on replacing that.

Short of testing the inverter for current, there isn't really anything you can do to tell if it's the inverter or the lamp, since the lamp is powered by the inverter. If one or the other failed it'd look about the same, though sometimes the lamp bulbs will flicker or work again for a little bit before they die completely.

I'd start with the cables first, though because that can sometimes be a cheap, easy fix for this problem and save you a lot of hassle messing with the bulb and inverter.

 

Any idea where I might be able to find disassembly instructions for my specific model?

 

Forget it. I found the disassembly instructions. I'll do what you said and check the cables before I try a new inverter. Thank you.

 

I need some additional help with this. I ended up replacing the inverter and it worked great for a couple weeks or so; however when the computer boots up now the initial screen comes up but it's got a distinct red tint to it. Then it flickers and you can hear a buzzing sound (almost like something is shorting out) and the screen turns off. I thought it might be the inverter again so I bought another one and the same thing happens with the new inverter.

Does anyone have any idea what could be causing this problem and, if so, is it something that is easy to repair on my own? I don't really want to put any significant money into this POS laptop but if it's something simple that I can do on my own, I'd like to fix it. Either way I'm going to look into getting another laptop (not a Toshiba) but it would make my life a bit easier if I could get the screen working again.

 

A redish or pinkish tint to the LCD image is almost always a due to a bad CCFL (i.e. the fluorescent backlight tube) that's going to fail in short order.

Basically you need to replace the CCFL at the bottom of the LCD. This job is definitely not for the faint of heart but is DIY-able regardless.

 

I have gone through the EXACT same problems with my M45. Just put in second replacement inverter. No luck this time. I think there is a design flaw. I called Toshiba and they basically told me to "@#$%-off". Nice. Please post here if you have any luck replacing the FFL. I will do the same.

 

Would I need to take the entire laptop apart to do this or would I just have to concentrate on the LCD disassembly instructions like I did when I replaced the inverter?

 

Basically the LCD lid must be disassembled (just like is required to get at the inverter) with an additional step: the LCD must then be removed completely from the hinges that are screwed in on both sides.

Then the fun part starts: removing the CCFL from the LCD itself. For this info with step-by-step pictures check out these links:
How to replace laptop backlight lamp (CCFL) <- for the general idea
Thinkpad 600E LCD CCFL Replacement <- for very detailed, step-by-step instructions (which apply to other laptops--not just ThinkPads)

I went through this myself on my old Satellite 5205 just about a month ago. I bought my replacement CCFL through Mouser Electronics and the CCFL is made by JKL Components.

Double check the diameter and length of one's own laptop's CCFL when it's removed from the LCD as the dimensions vary by LCD model. IOW, not all Toshiba laptops use the same size CCFL.

So, for example, my own Satellite 5205 has a 15" 4:3 aspect ratio LCD that's actually made by Sharp Electronics (part #LQ150U1LA03) which requires a CCFL measuring 2mm in diameter by 305mm in length. Note that rarely does a laptop manufacturer build their own LCDs and so most LCDs are made by Sharp, LG Philips, etc.

Also, speaking from personal experience, one might want to order two identical CCFLs as they are *very* easy to break accidentally when handling during installation.

 

Wow - thank you for that. Unfortunately, this repair seems a bit over my head so I think I'm just going to get myself a new laptop. I hate this thing anyway and I'm sure it's going to keep causing me problems. I'm going to see what kind of deals are available on other brands and make my decision. Thanks again for your help.