Raspberry Pi 3 no HDMI output

[RogtheDodge]

Hi
My 2 Raspberry Pi 3s won't display on my HDMI monitor (with 2 different HDMI cables) or my HDMIPi screen. Shows as 'no signal'.
Yet if I remove the sd card from the 3 and place it in my Raspberry Pi 2 it displays fine. So it's not the HDMI settings in config.txt!
BUT the Raspberry Pi 3s will work with my Motorola lapdock via HDMI!!

Help!

[masa-aud]

reply to RogtheDodge on RPi3 no HDMI out
So recommended is to retry connection of RPi3's HDMI exactly and also checking voltage of Power Supply enough for Pi3.

masa

[RogtheDodge]

Tried to connect again. 1st using Raspberry Pi 2 to HDMI all fine. Unplugged peripherals and sd card put into Raspberry pi 3 no signal on HDMI. The PSU I am using is 2.5 amps
Could the Pis be faulty?

[dom]

You wont get any hdmi output without a valid sdcard.
Are you sure your sdcard image is new enough for Pi3?
Latest Jessie from here should be.
Report output of "vcgencmd version" (on Pi2) to be sure.

[RogtheDodge]

Hi Dom
Thanks. You put me on the right road. The latest 'Jessie' did get me HDMI access. What wouldn't load HDMI was the latest 'BerryBoot' v13-03-16 for Pi 2 & 3. I needed this for my WD Pi-drive.
What's odd is that 'BerryBoot' and my LapDock did give me HDMI output! Very strange.
Thanks again