I made a simple circuit to read data from RS232 lines and print data on different RS232 lines. This is the IC I am using: MAX3232EIDWG4. The IC fails to convert the CMOS to RS232 level logic. I am suspecting it is because of a broken IC or because of the design.
As Elliot Alderson has spotted, you must connect CBYPASS between pins 16 (VCC) and 15 (GND).
Is it fine to connect RIN1 and RIN2 to read from either of these RS232 lines?
I don't know what you're trying to accomplish by doing so. But since these two pins are inputs you may connect them together.
ROUT1 and ROUT2 are connected together to get the same signal.
You mustn't connect output signals together. In theory both outputs should signal the same (since RIN1 and RIN2 are connected). But in reality one signal will be driven slightly faster than the other. This will cause a short on these outputs for a brief moment.
Is it fine to connect DIN1 and DIN2 to split my RS232 output lines?
DIN1 and DIN2 could be connected if you desire.
What are the consequences of connecting 2 different lines together?
As already stated, connecting outputs is a bad idea. You may connect inputs (CMOS: DIN, RS232: RIN), but I fail to see the benefit.
You can't put a capacitor in series with the 3V3 power connection. You probably intended that capacitor to be from 3V3 to ground.
After making that change, try using the device without connecting the inputs together. Measure the RS232 output voltages and report back.