CRT face down

No problem ... test away!

Can't see a problem.

In the 1930s CRTs were operated screen up, with a mirror lid used to view the picture. Today CRTs can be used in any and all positions.

NT

Your monitor can run in any position for testing.

Just take care to not knock the neck of the tube, or hit the monitor. It is possible for any small debris, or carbon pieces to fall on to the mask in the tube, and afterwards show in the picture. I've seen this happen.

Jerry G.

Tamme Bever wrote:

They could then too, the old electrostatic deflection tubes were so long they mounted them vertical with the mirror so the set wouldn't be so deep.

Jerry G is right on, don't do anything to the CRT tube that would cause any loose debris within the CRT to fall onto the shadow mask and cause a black spot by blocking the electron beam, or to go around the edge of the mask and scratch the phosphors themselves. The phosphors are coated on the electron gun side, but the material is easily disturbed and anything loose in the tube could scratch the phosphors.

H. R.(Bob) Hofmann

Jerry G. wrote: