[pondringjunkman]

So I dragged home this old(1986?) Blue KM3P. The graphics screen was dead, but it came with an extra CRT. Got the machine up and running, and swapped the crt, and it worked! Sort of... see the first photo- seems the image is too wide. The horizontal adjustment makes changes, but small ones that don't help. I have heard that caps can go bad? which ones should I be suspicious of?

Been lurking for a while, learning. Thanks to the help learned here, i got it running on my phase converter, and can program off single phase- tho had to move control and servo transformers to the good power leads. Thanks!!

[SoCalPE.com]

Usually you'll see slight bulging on the top of the caps when they are bad... hard to tell by the pictures.

[scrambled]

If you have the wrong screen in it will distort the image. I am working on a MD3, and I swapped my screens to try and figure out why mine was not working.

It has something to do with the screen refreash rate. I was told this will damage the screen if swapped for a long period of time.


Steve

[pondringjunkman]

Thanks very much for the replies! I don't see any swelling of the caps. Would the ones in question be in circuit with the wires going to the screen? The screen is best when the "cardboard tube" is adjusted all the way out- when the set screw is as far from the coil as possible.

The part number on the replacement crt was the same as the old one, and very different from the main crt.

On the old CRT, the external coil was easy to slip off of the tube. Is this intended to be an adjustment? Can the coil be safely backed off a bit- perhaps narrowing the picture?

Thanks again for the replies! I hope I'm not insulting anyone with dumb questions!

[bloke]

Look at the part number on the body of the HT coil (the part that has the flying lead that goes to the top of the CRT tube). I think you'll find that the CRT you fitted has the same number on the coil as the current text CRT.

[pondringjunkman]

Look at the part number on the body of the HT coil (the part that has the flying lead that goes to the top of the CRT tube). I think you'll find that the CRT you fitted has the same number on the coil as the current text CRT.

There are no similarities among any numbers for the graphics or main screen and their respective flyback transformers. No similarities exist between any of the component part numbers, yet the main screen works fine.