NO HDMI out, but detecting resolution properly, also VNC OK

Question

I am connecting monitor via 2 adapters VGA-to-DVI and then DVI-to-HDMI to my RPI v3. I've been using it in such manner on and off for a couple of years now and it always worked. After several months of pause I tried to power it up again and now I get no HDMI output. The power adapter is 2.5Amp. The card is obviously works, because I can connect via RealVNC. All other functions (WiFi, etc.) seems to be working.

Naturally I thought there might be a problem with my monitor, so I connected it to a working computer and I can see it's OK. Also I tried another monitor connecting to PI and same - no output.

Interestingly enough, apparently PI can properly detect which monitor is currently connected to HDMI port, as you can see on the screenshots of RealVNC Connection Property using 2 different monitors. The field "size" showing the correct maximum resolution supporting by each monitor, so at least some communication via HDMI port is functioning properly.

I have also tried hdmi_safe=1 with no success, other than forcing 640x480 resolution visible via VNC.

What can I do?

Answer 1

First clean the connectors. I'm a De-Ox-It fan. Swap and / or flex cables and watch for a response, ( very slow flex, if it works, the response won't be fast. )
Then try to eliminate adapters. Do you have a DVI monitor you can test on? Not the best time to bug all your friends to find an HDMI monitor you can try with. Hmm, just looked at my Pi3b, I wouldn't go after those solder spots. I find the micro connectors seem fragile, but the full-size hasn't seemed to be trouble (yet). Might try checking voltage at the Pi, doesn't seem likely that the video would be the only thing down. I'd also check dmesg, but I wouldn't expect to find anything.