It's just to get rid of any static charges, when the board is inserted into the chassis. This is because the edge is going to be the first bit that touches the chassis, and the capacitors have physically been placed with one end close to the chassis, and the other end connected to the PCB ground. As rachaelp says, its for the AC signal, that brief spike and then in theory the board ground and the chassis ground should be at a closer potential. Sometimes there is a parallel resistor too (>1M), to provide a high impedance DC path. In the duplicate thread (which makes it awkward to provide a good response, because it is only by chance that I saw it), it showed the portion of the schematic, with the ground connection on each side. However, it should have been drawn better, with a different symbol on each side to show the difference between board ground and chassis ground.
It's just to get rid of any static charges, when the board is inserted into the chassis. This is because the edge is going to be the first bit that touches the chassis, and the capacitors have physically been placed with one end close to the chassis, and the other end connected to the PCB ground. As rachaelp says, its for the AC signal, that brief spike and then in theory the board ground and the chassis ground should be at a closer potential. Sometimes there is a parallel resistor too (>1M), to provide a high impedance DC path. In the duplicate thread (which makes it awkward to provide a good response, because it is only by chance that I saw it), it showed the portion of the schematic, with the ground connection on each side. However, it should have been drawn better, with a different symbol on each side to show the difference between board ground and chassis ground.
