Long story short, I blew up the screen that came with my RAMPS 1.4. I had an existing display that came stock with the Wanhao Duplicator i3 (Melzi board). Here's how to make the appropriate harness.
First, some nomenclature:
RAMPS 1.4 Smart Controller Connector Adapter
Left port (EXP2) left to right, top to bottom:
1 2 3 4 5
6 7 8 9 10
Right (EXP1) port left to right, top to bottom:
1 2 3 4 5
6 7 8 9 10
Wanhao LCD port
Left to right, top to bottom
1 2 3 4 5
6 7 8 9 10
| Adapter Left (EXP2) | Wanhao LCD (EXP1) |
|---|---|
| 1 | |
| 2 | |
| 3 | 1 |
| 4 | 2 |
| 5 | |
| 6 | |
| 7 | 9 |
| 8 | |
| 9 | |
| 10 |
| Adapter Right (EXP1) | Wanhao LCD (EXP1) |
|---|---|
| 1 | 5 |
| 2 | |
| 3 | 8 |
| 4 | 7 |
| 5 | 4 |
| 6 | 10 |
| 7 | |
| 8 | |
| 9 | 6 |
| 10 | 3 |
I've since replaced the display but I'll post here for posterity as it may be useful to someone. As a side note, I find the service life of the mechanical components of these machines to be incredible. This is my first and only FDM printer which has been running since 2017.