This doesn't sound like a video card issue, it sounds like a short circuit somewhere (maybe a blown cap or resister? no way to tell without inspecting). Shutting down when you open the lid would indicate to me a safety mechanism when the unit detects a short or power spike trying to engage the primary display, and one of the involved chipsets terminates the power to avoid permanent damage. I don't believe it's a loose connector, because that isn't normally so predictable a result.
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This doesn't sound like a video card issue, it sounds like a short circuit somewhere (maybe a blown cap or resistor? no way to tell without inspecting). Shutting down when you open the lid would indicate to me a safety mechanism when the unit detects a short or power spike trying to engage the primary display, and one of the involved chipsets terminates the power to avoid permanent damage. I don't believe it's a loose connector, because that isn't normally so predictable a result.
This doesn't sound like a video card issue, it sounds like a short circuit somewhere (maybe a blown cap or resister? no way to tell without inspecting). Shutting down when you open the lid would indicate to me a safety mechanism when the unit detects a short or power spike trying to engage the primary display, and one of the involved chipsets terminates the power to avoid permanent damage. I don't believe it's a loose connector, because that isn't normally so predictable a result.