My X4 speed display is faulty and 2 digits of the speed are blank. I'd like to repair it as I'm guessing it is not possible to obtain a new module. The display driver is HT1621 but I have no idea what the display is. I have desoldered one side and lifted it but it has no markings at all on it. It is a 2.4" display with 4 large digits on left and on the right For Stop? and Rev in smaller letters arranged vertically. Any help on this will be hugely appreciated.