Have an issue with a DP-640B dimmer pack.
Firmware v1.1 (so says the MCU sticker)
I noticed on one of my dimmers that as channel values faded up (or down) through 22-23% (DMX 56 through 58), the connected lamp would dip to about 19% then back to the correct level as the fade continued.
When the channel was set to DMX 57, the dim level would be equivalent to DMX 51. Setting channel to DMX 56 or 58, the dim level was correct.
This behavior is consistent across all 6 channels and is clearly a firmware issue. I expected the affected unit had down rev firmware, but the sticker says v1.1 which is the same as a second DP-640B that does not exhibit this behavior. I swapped MCUs, and the problem followed the MCU. The firmware rev sticker on one of the MCUs is not correct (or the version was not changed for the build which included the fix).
How can I obtain a replacement MCU (or burn a new MCU) for the DP-640B with later rev firmware not containing the bug?