RAMPS + Arduino, not functioning

Hi (first post here!)

Sorry if the topic is a bit unclear.
I have just assembled a prusa i3 kit but have stumbled when coming to the electronics.

Problem:
When turning on the power supply, the RAMPS and Arduino are completely dead.

Facts:
I have measured the voltage just inside the screw connectors. Both lines are at 12.5V.
I have measured Vin to GND on the Arduino, it's at ~12V
I have unplugged the power supply, and connected the USB cable to my PC. The Arduino leds light up (a green and yellow one), and LED1 on the RAMPS turn on and off once. No connection is possible using Pronterface, with or without the power supply on.

Does anyone have any idea what might be wrong? Anything else I can do to troubleshoot?

Thanks and regards,
Rickard

Edit: Clarified No connection possible.
Edit2: I see now that this probably belongs in the Electronics/RAMPS forum

Edited 2 time(s). Last edit at 09/19/2014 08:45AM by rickard.

Have you uploaded the firmware to the Arduino?

Hi.

No, the Arduino is (supposedly) pre-flashed. Flashed or not flashed, I think some leds should light up when turning on the power (like when just powering up the Arduino).

Some more info.
I took the thing apart. Removed all the stepper drivers and separated the RAMPS from the Arduino. Same result.
I attached the LED display to the RAMPS. This also lights up when attaching the USB cable, but not with the power supply alone. It however contains a bunch of filled squares.

Edited 1 time(s). Last edit at 09/20/2014 11:45AM by rickard.

Uploaded the firmware (just in case!). The Arduino receives it ok, but the result is the same.

could this be a diode issue?, our both diodes soldered on the ramps

I'd forgotten to test Pronterface on COM3. Testing to connect on this port shows this text (or something similar):

Connecting...
ánP|hn“6ba8&6ŽIP|H.8]‹ˆŠHÈXÎjO>|9L]Hmjm~‹ˆŠHÈXñJ3ð^èÊK@óM³w·è%iþ
&ç}+MBOV7d6ë<ÂóHH6FñJ¤JLÿKÿLÿKª¹ÿÁÿZŽ*:&h/^7L*
JÄZäˆI¨ˆIˆŽJÿzˆxñ:&é>HŠ$P|þ%ÿ%þ%h%ˆxñé>JÐé+^^IjOé^xñJ„jâaHJàAHJP|@_!Ã&&·ÈM/Mvl
IM+j«6l*IÐ6X/+H^¬4ä&HóH
Æ&(N~L*Iàf8NL
x±JÄzbŽJjüJˆ(JˆjKàŽ
'*ƒMah$P|
žI¨jžIfñ
jo—FñJHáˆJ§a5O-Ž
ón†O=á6ñNmHñ/^fNn~_á~8é^H&NN6a„-HH&I`~!^ŒHoBOvHa7&‡þ

Regarding diodes. I measure 12V+ at D2, but only ~0.57V at D1. Can this be the problem?

Edit: And yes, polarity seems to be correct.

Edited 1 time(s). Last edit at 09/22/2014 03:57PM by rickard.

Quote
rickard
I'd forgotten to test Pronterface on COM3. Testing to connect on this port shows this text (or something similar):

Connecting...
ánP|hn“6ba8&6ŽIP|H.8]‹ˆŠHÈXÎjO>|9L]Hmjm~‹ˆŠHÈXñJ3ð^èÊK@óM³w·è%iþ
&ç}+MBOV7d6ë<ÂóHH6FñJ¤JLÿKÿLÿKª¹ÿÁÿZŽ*:&h/^7L*
JÄZäˆI¨ˆIˆŽJÿzˆxñ:&é>HŠ$P|þ%ÿ%þ%h%ˆxñé>JÐé+^^IjOé^xñJ„jâaHJàAHJP|@_!Ã&&·ÈM/Mvl
IM+j«6l*IÐ6X/+H^¬4ä&HóH
Æ&(N~L*Iàf8NL
x±JÄzbŽJjüJˆ(JˆjKàŽ
'*ƒMah$P|
žI¨jžIfñ
jo—FñJHáˆJ§a5O-Ž
ón†O=á6ñNmHñ/^fNn~_á~8é^H&NN6a„-HH&I`~!^ŒHoBOvHa7&‡þ

Have you double checked the port the computer sees the Arduino on?
Have you made sure the baud rate is the same in pronterface as what you have in your Marlin Configuration.h?

Steve

Thanks Steve. Setting the baud rate made the reception eligable.
It seems like the Arduino is functioning, so I'm going to connect everything again and see if the only thing not working is the powering the Arduino through the RAMPS (although it seems as if the error in that case still is on the Arduino side as Vin is powered).

I get the feeling power is not coming through.
After connecting everything and starting pronterface, I've tried running the motors and heatbed. Motors beep, and I've lowered the speeds to a tenth from the default (to 300 x/y, 20 z). Heatbed doesn't get warm at all, nor is there any indication it's on (no voltage on the line).