If it doesn't use an external power brick, but a normal kettle cord for power Typically it is a capacitor on the power supply side that's popped or swollen and is causing the issue.. replacing that generally resolves the problem and capacitors can be bought for less than 10rand..
I have fixed a number of monitors and flat screen TVs with this issue already..
On Voortrekker road, in Parow, between Parow municipality and giel basson drive is a place you can take it to.. I have no idea what they will charge to repair..