Con el Pronterface he calentado hotend y cama, incluso he extruido un poco de filamento... lo fijo a una temperatura y funciona.
Tambien probé a pasar el m303 con el hotend y la cama ya calientes y me pasa lo mismo...
De PID de momento no he tocado nada en Marlin está tal cual lo descargue...
/ PID settings:
// Comment the following line to disable PID and enable bang-bang.
#define PIDTEMP
#define BANG_MAX 256 // limits current to nozzle while in bang-bang mode; 256=full current
#define PID_MAX 256 // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 256=full current
#ifdef PIDTEMP
//#define PID_DEBUG // Sends debug data to the serial port.
//#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
#define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
// is more then PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max. (10)
#define PID_INTEGRAL_DRIVE_MAX 255 //limit for the integral term
#define K1 0.95 //smoothing factor withing the PID
#define PID_dT ((16.0 * 8.0)/(F_CPU / 64.0 / 256.0)) //sampling period of the temperature routine
// If you are using a preconfigured hotend then you can use one of the value sets by uncommenting it
// Ultimaker
#define DEFAULT_Kp 19.82
#define DEFAULT_Ki 1.31
#define DEFAULT_Kd 75.04
// Makergear
// #define DEFAULT_Kp 7.0
// #define DEFAULT_Ki 0.1
// #define DEFAULT_Kd 12
// Mendel Parts V9 on 12V
// #define DEFAULT_Kp 63.0
// #define DEFAULT_Ki 2.25
// #define DEFAULT_Kd 440
#endif // PIDTEMP