Extruder wont heat all the way

Hey guys,

I am in the precess of getting my pruse I3 rework up and running. When I try to heat up the hotends and the bed to start a print the bed heats up just fine, but then the hotend will olny heat up to around 130degrees and won't make it all the way to 230. I have dual extruders on my printer. I am stumpped on what to do. Any suggestions? I am using two j head hot ends, with a ramps 1.4 and an arduino mega 2560. Marlin is my firmware.

I have a few thoughts.

1) Can your power supply handle 2 hotends. I would disconnect 1 to see if it can get one hot enough.
2) Do you have anything sucking heat? I had issues getting one of my hotends hot enough, the issue ended up being that i had it in direct contact with a big chunk of aluminum. If your fan is running at 100% as its heating, it could also keep it from
3) Are you sure that your heater cartridges actually work? sometimes they just don't work and need to be replaced. Fortunetly they are really cheap on ebay, If I were you i would buy a handful of spares.
4) start checking your assumptions, it sounds like you are assuming that the temperature that the printer is giving you is correct, when it may not be. You may be assuming that your firmware knows what thermistor you are using, when it may not be and so forth.