Normal phenomenon on ‘Diamondtron NF-CRT’ monitors
Misalignment of Aperture Grille
Due to the nature of the Diamondtron NF-CRT, in rare cases, a misalignment of the aperture grille may happen by the shock or vibration caused during transportation. If a black vertical line appears on the screen, apply a light shock to the side of the monitor with your hand. If the problem persists, follow the procedure below.
ADisplay a full white picture and inspect the problem area.
BDisplay a high-white picture that covers the problem area to shoot a strong electron beam. Leave it for a while, until the problem disappears.
Damper Wires
The two faint horizontal lines that may be visible on the screen are actually the shadows of steel wires called Damper Wires. All Diamondtron NF-CRT based monitors have these wires for structural reasons.