Win7 computer boot has been long sounded and the solution

1, if it is constantly ringing (long sound), then it may be that the memory is not inserted or damaged, or the memory is dirty, resulting in memory can not be loaded;
Solution: Open the back cover of the chassis, unplug the memory module, then clean the dust and erase the oxidized part of the gold finger with an eraser. The memory slot is also cleaned up and re-inserted. If it still doesn't work. Then you can only replace one more memory.
2, if it is constantly ringing, it means that the power supply, the display is not connected to the display card;
Solution: Check all the plugs to see if they are plugged in.