beaglebone hdmi to VGA using powered Köning convertor not working ?

Feel free to do this modification. Just remember it violates the warranty. I do not intend to power the world over HDMI connector. Just the EEPROM for the purpose of reading the EDID. This is the way the board was design and is not a “feature”.

While the TPS65217 can handle more, it does have a limit.


Hi Gerald,

Agree :slight_smile: But at least consider a bigger fuse, a 250mA would be perfect. Those PTCs are not very good when current is near maximum point. They not actually switch, but increase their resistance due to natural construction and revert very slowly to initial condition (minutes). BTW this one has 4.5 ohms in normal state so when a big HDMI consumer will draw there will be no more +5V anyhow.

My reason is quite simple… I spent around 45 euro for board with all taxes and another 20 or more for cheapest HDMI adapter I found. So almost 50% from price and I see no point to spent more for a better adapter.

Edouard Gora, YO3HCV

Instead of changing the fuse and (probably) violating the warranty on the BeagleBone black, if I hack my microHDMI to VGA adapter and give it external power, would it work ?
Interestingly, the yellow thing does get incredibly hot and I see nothing past the beaglebone flash screen while boot, that too only after I edited the uEnv.txt file.
however the edid info obtained by logging into beaglebone through SSH (putty) shows 1 available resolution 1440x900@60Hz
with a different HDMI to VGA adapter 2 options are available 1920x1080 @ 60Hz and another one 1600 something by something. would that be issue of power supply to the HDMI to VGA converter or something else ?

thanks in advance

External power will work, as that is the one we recommend. The yellow thing is a PTC, not a fuse. It is designed to get hot and as a result increase the resistance with the level of heat to reduce the current flow.


Hello Gerald,
Thank you for your reply. The power supplied through the PTC turned out to be the issue. On my HDMI to VGA converter, I removed the power coming from beaglebone microHDMI port and added external power supply and it is working fine.
Earlier, even when I forced resolution, after 5 or 10 mins the PTC would become too hot and the monitor would go to to sleep, now It runs properly for a few hours.


Yes I know. It is the way I designed the board. I do not see it as an issue. It is designed to limit the current. You are free to change it if you like as long as you don’t expect any RMA support on the board.