Hewlett-Packard Pavillion DV6500 Notebook Repair. (Artefacts on the Screen)

Today I will show you a repair process of the Hewlett-Packard Pavillion DV6500 Notebook based on Core2Duo T5450 CPU and GeForce 8400M GS graphic card.
Customer said: "Multiple problems, but main - computer doesn't show display correctly. Looks like LCD is dead." Then my question was: "Did anybody has opened it before." Customer's answer: "No. Nobody. Laptop looks like new. I know, may be it is difficult to fix it, so I'm ready to sell it for parts." I've answered: "Ok. I'm ready to look at it."

I've received a laptop.
Condition: I've never saw worth in my life. One button is missing, scratches everywhere. Looks like somebody very far not professional tried to fix it. All the top surface of the screws was damaged. I've spent a lot of time when tried to unscrew them.

I've tried to connect universal power adapter (original power adapter was missing) and turn it on... no success.
LED indicator around the power connector was on (blue light), I've tried to take off the connector, but it was very hot. Something wrong with battery, may be short circuit inside. Battery was bigger size than original, somebody replaced it. So, I took off the battery, and power connector became normal. After a few tries to power on the laptop A've moved my finger and pushed near the power on button. It is started...

Deffinately, something wrong with the graphic card. And there is only one way to fix the notebook, at least make it temporary working.

Repair process:

1. Take off the RAM and the Hard Disk Drive. Then unscrew all the screws on the bottom (including the screws under the battery, because they are holding the touch panel above the keyboard) and take off the DVD-RW.

2. Then turn the laptop around. Took off the touch panel and the keyboard. Be carefull with two ribbon cables, which connecting the touch panel with the motherboard. In my laptop they are was damaged and also connected wrong, because of this the laptop didn't turn on. It turned on only when you touching the touch panel. Then unscrew all the screws under the touch panel and under the keyboard.

3. Split the notebook's case and take off the top part. Under it you will see the motherboard. Unscrew all the screws, which holds the motherboard, unplug a few cables from it and take it off.

4. Now you have to take off the CMOS battery, and using the hot air or infrared solderer to warm thoroughly the surface right behind the graphic card processor (GPU). This needed to make better the GPU contacts with the motherboard. This way of repair will not guarantee anything. It is only for emergency cases. (Not finished work or some programs which runs only under the particular operation system from this notebook.) After that you have to save the data and utilize the laptop or sell it for PARTS ONLY with problem and repair explanation.

5. During the assembling of the laptop, I found that on of the ribbon cables between the touch panel and motherboard is damaged. (which goes to the "power on" button) That two cables look same, I've tried to replace them. But nothing works. I found, which cable is working, the I've connected it to the power button and I've left the touch panel off. (I didn't connect the damaged cable, otherwise even power button is not working.) But now the touch panel is not working, but the power button is more important.