Charge controller

If it still works as a PV controller then there is no need to get a new one unless you particularly want to see the input / output numbers ..

Most of the new controllers and MPPT units only have LEDs to indicate connected , charging and battery SOC ..

Cheers

Steve

ronox,

'black squares' makes me think your readout is a 'seven segment LED' type.
LEDs don't burn out just like that. So you'll most likely be able to fix it by opening up the unit and look for bad connections. If there are some cable connectors on the circuit board, wiggle them a bit in their sockets.
Sometimes it even helps to tap the case with the screw driver handle while the unit is in operation, but be gentle.

Best regards, Peter