I recently happened upon a bunch of small form factor monitors that were mostly functional save 1 14M4U with a bad tube. Since this series is one of the higher end Pro monitors I set about trying to find a replacement. I am lucky enough to have a few of these already laying around, including one that needs a recap. So in order to save myself time and a lot of headache, I decided to opt for a simple tube swap.
Note: the usual rules apply here when working on a CRT. Make sure you discharge the tube fully and remove the anode cap.
The 14M4U is a small monitor and quite modular.
The power supply board and the board to the right are held in by 2 screws that attach to the metal shield surrounding the picture tube.
The motherboard can be slide out from underneath the tube as on most Sony monitors.
Power and RGB lines.
The C board is held on by suction and can simply be pulled off by the yoke.
You will likely have to unscrew these grounding plates on the terminal board.
It always helps to have a picture of where each connector goes.
The tube on these units is fairly light, so i opted to simply switch the cases in order to avoid having to completely tear down the whole monitor as I had 2 identical 14M4U'S.
Once you have the tubes swapped you will likely have to do some adjustments to align the picture. Luckily I was able to do this mostly in the service menu. If you cant get the picture right you may have to adjust the deflection coil/magnets around the yolk.