Toshiba Satellite C660D-155 Screen or board

[rudger]

I have a toshiba C660D-155 Laptop on the bench at the moment it has a 15.6" Chunghwa CLAA156WB11 LED Screen fitted which is showing the attached picture im 99% Sure that the screen has failed however the customer advised me that it has been to another IT Company twice before it was brought to me for repair.

Just over 12 Months ago the screen was changed as it was showing the exact same problem and the fault has reoccured now the other IT Company are saying that the fault is not the screen but with the mobo I have been brought in by the owner as they are looking for a 2nd oppinion. I have tested the laptop on an external monitor and it is working fine which makes me think that it is the screen once again.

can any of you guys think what else could have caused the screen to fail twice or why the mobo could have caused the fault.

Thanks in advance

Rudger

 

[andyroe208]

Hi Rudger

I would have been the same as you when I first started dealing with repairs, if it works on an external display then it must be the screen , however I then started at the biggest seller of computers in the UK (I won't give them the satisfaction of actually naming them) and actually learnt that this isn't always the case in fact I had a big argument with a colleague of mine at the time about this situation. I said it was the screen and they said it was the board. Needless to say in the end I had to apologise as they were right (They had been working there for several years).

Now to answer your question I never got to the bottom of how it was the mainboard I just remember it so I hope others could answer that question for you.

What I would do if you haven't already is test another screen on it to see if it is just the screen that has failed, this obviously won't tell you if the board is causing the issue over time though, but I have found that if the board is the issue it won't be fixed even temporary when putting the new screen in. Obviously if the new screen is used and the issue is still the same then you know straight away the issue is not the screen. (I did read the post but couldn't see if you actually had done this)

I hope this makes sense to you and is of help

 

[andyroe208]

Oh and have you tried the harness/LCD cable just in case?

 

[rudger]

I must admit I have always found it to be the screen every time I have seen this problem I always checked with an external monitor and if the display on an external monitor is fine then I have replaced the screen, I have checked the Harness cable and it seems fine, no signs of damage and no improvement if the cable is moved the only problem is I dont have a similar screen to connect to prove the screen

Rudger

 

[andyroe208]

I do agree with you on the fact that 99.99% of the time it is the screen but on the odd occasion I have found it is the board. Without testing a new screen it really is hard to tell where the main problems lie. If someone else has more experience about this sort of thing it that would help also. Where I worked money was no object nor were parts, if we replaced the screen and it didn't work we would replace the board, if that didn't work we would replace the harness. OK this is the right way to go and some would have just called us glorified parts fitters and not technicians although most of us got it right the first time. That is one of the main reasons I left the company.

 

[NYJimbo]

A couple weeks ago a DV9000 came in with a green screen. Everything looked fine except there was way too much green, but some other colors could be seen. He also took it to a shop which said it was the LCD but they wanted $250 to replace it. I had a cracked LCD which would work and sure enough the green was on there too. The LCD cable looked perfect and no amount of flexing would change the picture in the slightest bit. I started to think it could be the LCD side of the board/GPU because I have seen weird stuff before, but I bought a DV9000 cable and after that the picture was perfect. If the cable isnt too expensive tell the customer you want to go that way and see if the cable does it.

I find it hard to believe the motherboard would suddenly be the problem if before it was the LCD. I think they just got lucky with the cable. A few months ago I replaced a broken LCD and a few days later the customer brought it back with a red screen. Same thing about the cable, I couldnt get it to shift colors on flexing so I thought the LCD might have gone, but I had a cable in stock for that unit and that was the fix.

 

[andyroe208]

Hi NYJimbo

The good old DV9000. they are known for their terrible graphics and will forever need reflowing or a new mainboard all the time. You must have got lucky on this one with it being the cable but yes I agree the cables are relatively cheap so this could be an option, even if that isn't the problem it's not too much money tied up until you can use it.

Yes it is hard to believe it is the board but without any other screen to test that can't really be ruled out.

 

[javjim]

You have 3 options.

LCD, LCD FLEX CABLE or motherboard.

I would begin with the lcd flex cable. sometimes they go wrong

try to wiggle it and see if it changes something

 

[frenchscottie]

I've had faulty cables that no matter how much you wiggle, twist or wobble the picture doesn't change. Also be carefull as it can also catch fire or give you a shock if there is a broken wire or 2.
Some weird effects you can get from a bad cable are :- A 2 by 2 grid of an exact copy of the screen, i.e 4 identical screens. or 2 screens squashed vertically, 2 inch band down the left side of screen, 4 colour display, wrong colours i.e. blues are green, reds are pink etc. And loads more.
As said above i'd change the cable first if I wasn't sure the cause.

Mo

 

[taeknikall]

This thing has made diaq screen a bit easy

lcdparts.net/LST01.aspx

If you have the option to test another led with this unit , could be better to test another led if you dont have another cable to try..

 

[rudger]

Well a quick update to the situation I Decided to go for the replacement screen as it was not too expensive, however the screen I recieved is also faulty - (totally different Fault to the screen fitted) but it has done enough to prove that it is a screen fault im now expecting another screen on monday.

Thanks for your help everyone.

Rudger