I've been using a CA-42 (Nokia official) as an interface for a while now but it stopped working recently. The loopback test shows everything OK, but it won't program either of the two units I tested it on.
Using Port : \\.\COM38 Using Programmer : arduino Overriding Baud Rate : 115200 avrdude: Send: 0   avrdude: Send: 0   avrdude: Send: 0   avrdude: Recv: 0  avrdude: stk500_getsync(): not in sync: resp=0x30 avrdude done. Thank you.
There's definitely communication happening--it doesn't have wait for a response before getting the ACSII 0 in return. I tested for a short, but that's not it either.
Here's how I have it hooked up if it helps:
RED --> 5V
BLACK --> GND
BLU --> 1k resistor --> D1
WHITE --> 1k resistor --> D0