Sorgelig wrote:If signal would really so weak, then many users should complain. Currently only you complain. So it means it's something special in your case. Probably your de10 is defective.
It's not only him -- I have the same problem with my MiSTer. It frequently causes either my HDMI switch to freak out, or (when I bypass the switch) my Sharp AQUOS HDTV to lose sync, or both, depending upon the length and quality of the HDMI cable I'm using. None of the other devices (including Raspberry Pi 3B+) hooked up to the same exact inputs have any issues like this. I too have replaced my power supply with one of the 3A Raspberry Pi power supplies in hopes of providing a little more power, but still experience the same issue.
Another thing worth noting -- when the HDMI is struggling and desyncing, a secondary symptom is that memtest claims my 128GB SDRAM is only stable at 120. To get it to be stable at 140, I have to swap out the HDMI cable for a shorter one.
And there's a third symptom also: when the HDMI is struggling and desyncing, then sometimes my USB wifi dongle or my USB Bluetooth dongle (or both) will randomly fail to work (their little icons just never appear in the top bar of the MiSTer menu).
All of these things taken together suggest to me that the overall power delivery is insufficient. I'm thinking about trying an even higher-amperage supply, and possibly a *slightly* higher voltage supply, to see if that cures things.