The relationship between resume-from-suspend failures (and other monitor-related anomalies) and bad Display Port cables & adapters:
When using certain incorrectly manufactured 3 rd party Mini DisplayPort to DisplayPort cables to connect a display to a host computer, problems such as the following may arise:
- Host computer is unable to power on.
- Host computer is unable to correctly enter sleep modes.
- Host computer is unable to correctly resume from sleep modes.
- Display is unable to be turned on or display video correctly.
- Incorrect display resolution or corrupted video is shown.
Technical description of cause
Certain Mini DisplayPort to DisplayPort cables available in the market do not adhere to the DisplayPort design wiring specification. This incorrect design causes power-related issues with the display and/or host computer.
The DisplayPort specification states that a display (known as a “sink” device) must output power on its DisplayPort input connector. The specification also states that a graphics adapter (known as a “source” device) must also output power on its DisplayPort output connector. The idea for providing power on both the “source” and “sink” devices is that certain other devices connected between the two can receive power. Such devices may be, for example, a repeater or a converter of some sort.
When a cable is used to connect a display directly to a graphics adapter, the DisplayPort specification states that the cable must not connect the power line, and the power outputs of the two devices should not be connected together via the cable.
The cables that were manufactured incorrectly connect the power line through the cable and allow the power outputs of the display and graphics adapter to be connected together - a condition that is forbidden in the DisplayPort specification.
Because the two power sources are connected together when using one of these cables, situations can arise in which one device is actually supplying power to the other. For example, if the host computer is powered off but the display is on (or even in standby mode), the display will inadvertently supply power to the host computer, which may cause problems such as not being able to power on, enter sleep modes or resume correctly. Similarly, if the host computer is powered on but the display is off, the computer will be supplying power to the display, which may cause problems with the display powering on."[/i]
Notice regarding incompatibility of certain 3rd party DisplayPort video cables
Special thanks to dudepare for finding the above document:
(Page 38, Posts #556 and #557)
Black Screen on Windows Login (344.16 and .11) on DisplayPort with GTX980 SC (Fix info posted 11/25/ - GeForce Forums
How to Choose a DisplayPort Cable, and Not Get a Bad One! - DisplayPort