My computer is a Pavilion DV-4 1465dx, which I purchased in the summer of 2009. I upgraded from Windows Vista to Windows 7 last fall. (About time!) The only hardware problem I had before this year was a corrupted hard drive, which I replaced over the 2012 summer. In late April 2013 however, I lost video in the LCD. This problem occurred without much warning, aside from a slight display flicker once when closing the laptop, perhaps the last time the screen worked properly. There had been other indications of hardware issues – the webcam would only work at certain screen angles – which led me to believe there was a faulty connection in the display cable.
To provide more information on the problem itself, the screen powers on but shows no image, just a uniform grey appearance. I can vary the screen’s brightness by both software and hardware input, but I have no image itself. The computer appears to function completely normally everywhere else – it still boots normally, still recognizes the display, operates normally, and outputs perfect video when connected to an external monitor.
I searched online for potential solutions and found that these models often had trouble with the display cable. This seemed to match my symptoms of screen power but no signal, and spotty webcam connections. If I understood correctly, the performance also ruled out problems with the inverter (the little circuit board at the bottom of the screen) because the screen still had power and brightness control. I purchased a new cable (and a new LCD, as I had cracked the old one in haste to remove the screen bezel, not my best moment) and when they arrived, I connected and reassembled everything on my laptop, and powered it on. Nothing had changed. The same exact performance and issues were present. Confounded, I tested both cables, pin for pin, with a multimeter, only to find that one of the connections for the original cable *was* broken, and that the replacement cable was intact. (I drew diagrams of the wiring as I tested, and I can post these if seeing them would help?) I had fixed the cable, but had not restored display functionality, which meant that somewhere else in the system there must be a broken circuit.
This is where I need help! The laptop is no better, and no worse. Further searches online suggested that there might be a broken solder on the display chip’s BGA (ball grid array) connection to the motherboard, which can only be repaired by heating and “reflowing” that area of the board. However, I understand that this is a potentially risky procedure due to heat-sensitive motherboard elements (capacitors). Additionally, I believe that if there are connection issues on the motherboard, I would see some combination of flashing Caps Lock and Num Lock lights? This has not been observed.
I purchased a new computer (a Surface Pro) this summer, but I still anticipate using this laptop in some situations, if possible. Is there anything else I can try, short of cooking the processor with a heat gun? Any diagnostics I can run that might shed more light on this situation?
