Contact your supplier if these steps do not help. These steps may vary depending on manufacturer configuration. This is a generic troubleshooting guide for RAMBo.
F4 is a 15A ATO (the type found in many automotives).
F3 supplies the extruder heater + fan outputs and logic.
F2 supplies the motors and on-board power supply.
An example part number for replacement fuses is 0448005.MR Fast or very fast acting are recommended. The small white fuse holders are Little Fuse OMNI-BLOCK fuse holders.
High quality, High temperature FR4-TG130 PCB.
Built in SMPS for 5V generation from Extruders + fans and logic.
Motors, 5A 12-28V (fuse can be exchanged for up to 10A capacity).
Extruders + fans and logic, 5A 12-35V (fuse can be exchanged for up to 10A capacity).
Three independent power rails for flexible input power configurations.
Proper fan connector placement is shown in the figures below: Fan has a 3-pin power connector desktop board has a 4-pin fan header: Note: when using a 3-pin power connector with a 4-pin fan header, the fan will always be on there is no fan control.
Low resistance mosfets for cool running Fans and on-board fan headers are backwards compatible.
If you wanna make your fan work you'll need a 5V source and connect it to the PWM pin (100 speed). Accepted voltages are TTL standarts - so, max voltage is a bit above 5V - hence your busted 15 fan.
#4 pin fan pinout drivers
Extra driver ports broke out for up to 3 additional drivers (some of the motor extension pins are shared with max endstop and a pin allocated for SPI-SS extensions) 4 pin fans use Pulse Width Modulation to regulate speed - the PWM pin.
Step and Direction pins are on their own ports for synchronous movement capability.
2-11 in which vector 1 is 120 degrees in advance of vector 2 and the phase. This pinout and color scheme applies to fans made by Delta Electronics, models BFB0412HB (Apple P/N 603-5520), BFB0612H (Apple P/N 603-5519), BFB0812H (Apple P/N 603-6624), and others.
Microstep mode configured by MCU through firmware (no jumpers needed) Thanks go to Bob Wilson (volvodad on Brickboard) for contributing to these differences.
Current limit on driver IC VCC to prevent permanent latchup.
Input/Outputs pins: A GPIO pin set as Input reads the signal received by the Raspberry Pi, sent by the device connected to this pin. All the voltages are measured with respect to the GND voltage. GND: Ground is commonly referred to as GND.
Digital Trimpot for stepper current control 3.3V: The 3v pin is used to provide a stable 3.3v supply to external components and also to test LEDs.
5 A4982 1/16th microstep motor drivers(2 connectors on Z for Prusa Mendel and other dual Z printer designs).
v1.4 added EXP1 EXP2 connectors for LCD.
All extra pins broken out on both processors (allows using the 32u2 for LUFA AVR programmer, etc.).
Crystals for both usb and mcu (timing accurate to 10ppm).
Arduino MEGA compatible Atmega2560 and Atmega32u2 processors are compatible with all RAMPS class firmware.
The USB connection is isolated from the rest of the board and cannot be a power source. You must connect an external power source to the Heater, Fans, and Logic input for the RAMBo to operate.