R.Pi gratuitous & frequent screen blank - hardware problem?

Question

Have been using my Pi for 2 weeks, but recently discovered the monitor displaying "No Signal", and the screen went blank for a few sec before returning to normal display. I don't believe this is the config issue that other people have been up against. Powering down the Pi and letting it restart solved the problem for up to 30 min. but after leaving it down for the weekend, the problem is back this morning with a vengeance. Can't edit code! Once upon a time I thought the problem was triggered by performing an action which resulted in the display being updated.

I'm using an HDMI/VGA converter with a Benq monitor. Have tried changing monitor, VGA lead, and converter none of which has helped. BTW my Pi is an older model, the board printing says (c) 2011.12 ...

Is the Pi HDMI o/p known to be intolerant of HDMI/VGA converters over a period of time? Apart from the config issues, has anyone else seen (and solved) a problem like this?

EDIT

hdmi_force_hotplug=1 is already in /boot/config.txt hdmi_safe=1 was hidden with a # at the start of the line

on rebooting, got the pretty rainbow colours on the screen, then nothing ... just blank :(

Answer 1

Plausible theory: HDMI/VGA converters need power, and RPi might fail to provide enough. Once the converter shuts down because of lack of power, the RPi sees there's nothing connected to its HDMI port and disables the video.

Try running with hdmi_force_hotplug=1 and hdmi_safe=1 in your /boot/config.txt The first setting specially should help, if my theory is correct.

Edit: rainbow colours indicate power supply problems which result in all kinds of glitches, sometimes hard to reproduce or seemingly random. You'll need to find a better power supply for your RPi. Aim for something rated at 2A or more to be sure.