ER-301/Maintenance and Repair
Replacing the CPU Board
Sometimes it is necessary to replace the CPU board on the ER-301. This process is easy and safe as long as you take your time, take basic anti-static precautions and do not force anything.
- Purchase a replacement CPU board (AM3352-SOM) from Olimex for about 37EUR: https://www.olimex.com/Products/SOM/AM335X/AM3352-SOM/
- Remove the rear uSD from the old CPU board and insert it in the SD slot on the new CPU board.
- Carefully pull off the old CPU board by prying up each side little-by-little. Do NOT try to forcefully pull it off all at once. Here is a step-by-step tutorial on how to remove the CPU board: ER-301/CPU_Board_Removal
- Carefully align the pins and push on the new CPU board. It is very important that you use both hands, pressing ONLY on all 4 corners evenly. Do not push on the center of the board and especially do not push on the area with the Olimex logo. Underneath the logo is the RAM chip which might be damaged if you press here.
Removing the panel
You will need...
- a 1.5mm allen wrench for the knob's set screw.
- a 12mm socket wrench for the nut on the encoder bushing. An adjustable wrench is fine for this also.
- an 8mm socket wrench for the jacks. Cover the end of the socket wrench with felt or any similar cloth. The finger-tip of an old glove also works.
If you feel confident removing the panel on your ER-301 and replacing button caps, you can try doing it yourself. The part number for the gray buttons is D6C10-F1-LFS:
Mouser https://www.mouser.com/ProductDetail/CK-Components/D6C10-F1-LFS (Ignore the round green button in the picture.)
Digi-key https://www.digikey.com/products/en?WT.z_se_ps=1&keywords=D6C10-F1-LFS (Ignore the black button in the picture.)
I find that prying off the button caps is most conveniently done with a 2mm flathead screwdriver. Here is what the process looks like: