<p><em>Although it appears to be a RAMPS compatible board as described in <a href="/a/11477">this <strong>now deleted</strong> answer</a>, <strong>it is not using a RAMPS pin configuration</strong>.</em> </p>

<hr>

<p>To fix this in the firmware, this requires an upload of newly configured firmware to the board. See e.g. question: "<a href="/q/5848">How to upload firmware to reprap printer?</a>". For Marlin firmware (which is also loaded at the factory) You need to assign the correct board number or constant name (amongst several other things) in the <a href="https://github.com/MarlinFirmware/Marlin/blob/2.0.x/Marlin/Configuration.h" rel="nofollow noreferrer">Configuration.h</a> file. Note that this is "clearly" described by the manufacturer <a href="http://www.geeetech.com/wiki/index.php/GT2560A/GT2560A%2B" rel="nofollow noreferrer">here</a>.</p>

<p>From factory, a version of 1.1.X is loaded note that version 1.1.9 is the last of the 1.x branch, the default is now version 2.x.</p>

<p>From the <a href="http://www.geeetech.com/wiki/index.php/GT2560" rel="nofollow noreferrer">manufacturer of your board</a> you find that:</p>

<pre><code>#define MOTHERBOARD 7
</code></pre>

<p>needs to be set. Note that using number is old, nowadays you would use a constant. For board number <code>7</code> this is the constant defined as <a href="https://github.com/MarlinFirmware/Marlin/blob/2.0.x/Marlin/src/core/boards.h#L73" rel="nofollow noreferrer"><code>BOARD_ULTIMAKER</code></a>. Note that in version 2.x this number is now 1117, so the preferred usage is the constant name <code>BOARD_ULTIMAKER</code>!</p>

<p>Specifically for your board, the Configuration.h file should contain:</p>

<pre>
#ifndef MOTHERBOARD
  #define MOTHERBOARD BOARD_ULTIMAKER
#endif
</pre>

<p>The pin arrangement used by this board is found in <a href="https://github.com/MarlinFirmware/Marlin/blob/2.0.x/Marlin/src/pins/ramps/pins_ULTIMAKER.h" rel="nofollow noreferrer"><code>pins_ULTIMAKER.h</code></a>.</p>

<p>In this pin file you need to swap the pin numbers that identify the bed and the second extruder (<code>E1</code>) thermistor pin. In this file change:</p>

<pre>
//
// Heaters / Fans
//
#define HEATER_0_PIN        2
#define HEATER_1_PIN        3
#define HEATER_BED_PIN      4
</pre>

<p>to: </p>

<pre>
//
// Heaters / Fans
//
#define HEATER_0_PIN        2
#define HEATER_1_PIN        4 // or -1
#define HEATER_BED_PIN      3
</pre>

<p>Note that it could be that the <code>E1</code> heater output may not be designed to take the high current load the bed requires (depends on the traces on the board and the used MOSFET; with respect to the MOSFET, <a href="http://www.geeetech.com/wiki/index.php/GT2560A/GT2560A%2B" rel="nofollow noreferrer">the manufacturer states</a> that:</p>

<blockquote>
  <p>3 55Amp MOSFET (with LED indicator, the actual output is restricted by the PCB board and the connector), all 3 MOSFET are equipped with heat sink to ensure sufficient heat dissipation and stable operation</p>
</blockquote>

<p>, implying that the MOSFETs are identical). It is therefore advised to use an external MOSFET module. This will keep the high currents away from your printer board. Such a module looks like:</p>

<p><a href="https://i.sstatic.net/aMcjA.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/aMcjA.jpg" alt="MOSFET module"></a></p>

<p>You need to wire the second extruder heater leads to the white cable, the power and the bed leads use screw terminals and are clearly labeled.</p>

CC BY-SA 4.0
2019-12-05T14:03:34.930Z
Don't forget you have to walk them through how to install the compiler, get the source from git hub et al.
user77232
CC BY-SA 4.0
2019-12-05T14:05:00.663Z
@user77232 No that is not necessary, there are already questions on that front. I'll link them.
0scar
CC BY-SA 4.0
2019-12-05T14:48:11.987Z
Oops, I only read that the board "integrated 2560 and RAMPS" - didn't know they weren't competent enough to route it similarly.

Marlin 2.0 has just been released out of bugfix though.
towe
CC BY-SA 4.0
2019-12-05T15:30:24.910Z
@towe +1 for the 2.x statement! I have updated the answer, many thanks!
0scar
CC BY-SA 4.0
2019-12-05T12:43:49.263Z
2019-12-05T15:29:37.860Z
2019-12-05T15:29:37.860Z
0scar
<p>If you want to use Extruder heater and thermistor 2 as a hotbed driver, then you will need to get an external mosfet, since I doubt that the extruder heater mosfet will be able to handle the required current. Then in your slicer, just remap the bed from BED to E2</p>

CC BY-SA 4.0
2019-12-04T15:35:58.313Z
2019-12-04T15:35:58.313Z
user77232
<p>The heated bed output on my printer recently stopped working. I have an output for a second hotend. How can I reprogram this output as a heated bed output? The board is a <a href="http://www.geeetech.com/wiki/index.php/GT2560" rel="nofollow noreferrer">Geeetech GT2560 rev A+</a>.</p>

CC BY-SA 4.0
2019-12-04T15:30:44.353Z
Have you tried using the other heater output in the G-Code? Like E3 or something? What is the label of the other heater that you're talking about? Is it the extruder heater or a secondary bed heater? Do you have a pic of the output you're talking about? Can we see it? Do you have an environment for compiling the firmware? Do you know what firmware it is using?
user77232
<heated-bed><reprap><geeetech>
How to use second hotend for bed heating?
Matěj Musil
# How to use second hotend for bed heating?

(Asked by: username_0 on 2019-12-04)

The heated bed output on my printer recently stopped working. I have an output for a second hotend. How can I reprogram this output as a heated bed output? The board is a [Geeetech GT2560 rev A+](http://www.geeetech.com/wiki/index.php/GT2560).

**Tags:** heated-bed, reprap, geeetech

> **Comments:**
> **username_1**: Have you tried using the other heater output in the G-Code? Like E3 or something? What is the label of the other heater that you're talking about? Is it the extruder heater or a secondary bed heater? Do you have a pic of the output you're talking about? Can we see it? Do you have an environment for compiling the firmware? Do you know what firmware it is using?  

---

## 2 answers

### Answer by username_2 on 2019-12-05. Score: 2

*Although it appears to be a RAMPS compatible board as described in [this **now deleted** answer](/a/11477), **it is not using a RAMPS pin configuration**.*

---

To fix this in the firmware, this requires an upload of newly configured firmware to the board. See e.g. question: "[How to upload firmware to reprap printer?](/q/5848)". For Marlin firmware (which is also loaded at the factory) You need to assign the correct board number or constant name (amongst several other things) in the [Configuration.h](https://github.com/MarlinFirmware/Marlin/blob/2.0.x/Marlin/Configuration.h) file. Note that this is "clearly" described by the manufacturer [here](http://www.geeetech.com/wiki/index.php/GT2560A/GT2560A%2B).

From factory, a version of 1.1.X is loaded note that version 1.1.9 is the last of the 1.x branch, the default is now version 2.x.

From the [manufacturer of your board](http://www.geeetech.com/wiki/index.php/GT2560) you find that:

```
#define MOTHERBOARD 7

```

needs to be set. Note that using number is old, nowadays you would use a constant. For board number `7` this is the constant defined as [`BOARD_ULTIMAKER`](https://github.com/MarlinFirmware/Marlin/blob/2.0.x/Marlin/src/core/boards.h#L73). Note that in version 2.x this number is now 1117, so the preferred usage is the constant name `BOARD_ULTIMAKER`!

Specifically for your board, the Configuration.h file should contain:

```

#ifndef MOTHERBOARD
  #define MOTHERBOARD BOARD_ULTIMAKER
#endif

```

The pin arrangement used by this board is found in [`pins_ULTIMAKER.h`](https://github.com/MarlinFirmware/Marlin/blob/2.0.x/Marlin/src/pins/ramps/pins_ULTIMAKER.h).

In this pin file you need to swap the pin numbers that identify the bed and the second extruder (`E1`) thermistor pin. In this file change:

```

//
// Heaters / Fans
//
#define HEATER_0_PIN        2
#define HEATER_1_PIN        3
#define HEATER_BED_PIN      4

```

to:

```

//
// Heaters / Fans
//
#define HEATER_0_PIN        2
#define HEATER_1_PIN        4 // or -1
#define HEATER_BED_PIN      3

```

Note that it could be that the `E1` heater output may not be designed to take the high current load the bed requires (depends on the traces on the board and the used MOSFET; with respect to the MOSFET, [the manufacturer states](http://www.geeetech.com/wiki/index.php/GT2560A/GT2560A%2B) that:

> 3 55Amp MOSFET (with LED indicator, the actual output is restricted by the PCB board and the connector), all 3 MOSFET are equipped with heat sink to ensure sufficient heat dissipation and stable operation

, implying that the MOSFETs are identical). It is therefore advised to use an external MOSFET module. This will keep the high currents away from your printer board. Such a module looks like:

[![MOSFET module](https://i.sstatic.net/aMcjA.jpg)](https://i.sstatic.net/aMcjA.jpg)

You need to wire the second extruder heater leads to the white cable, the power and the bed leads use screw terminals and are clearly labeled.

> **Comments:**
> **username_1**: Don't forget you have to walk them through how to install the compiler, get the source from git hub et al.  
> **username_2**: @username_1 No that is not necessary, there are already questions on that front. I'll link them.  
> **username_3**: Oops, I only read that the board "integrated 2560 and RAMPS" - didn't know they weren't competent enough to route it similarly.  Marlin 2.0 has just been released out of bugfix though.  
> **username_2**: @username_3 +1 for the 2.x statement! I have updated the answer, many thanks!  

---

### Answer by username_1 on 2019-12-04. Score: 0

If you want to use Extruder heater and thermistor 2 as a hotbed driver, then you will need to get an external mosfet, since I doubt that the extruder heater mosfet will be able to handle the required current. Then in your slicer, just remap the bed from BED to E2


---

