Re: 7104 strange beam shape
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Hi Chris , I had that effect on one of my 7104's some tears ago , if I remember correctly there is a preset focus control - maybe focus range control near the rear right-hand side if you take the cover off . One other thing to check is the beam finder switch as it affects several circuits and could affect the focus if not all sections of it are working .
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Brian (UK) On Wednesday, 23 February 2022, 23:31:51 GMT, cmjones01 <chris@...> wrote:
I've just tried to use my 7104 for the first time in a few months. It's been stored in the attic of my house for that time. When put away, it was working really well. It still seems to be working well but the spot on the CRT is no longer a spot but a strange-shaped blob. The blob is one or two inches in diameter, has sharp edges, and its shape and size vary with the focus and astig controls. It doesn't come across well in a still photo (especially as the image is a bit muddled by the worn areas on the MCP) but I made a very short video of what it looks like: I don't have much time to spend on this, so I'll probably end up just putting it back in the attic for another day. I couldn't resist a quick look inside but nothing's obviously come adrift. Has anyone seen these symptoms before and figured out their cause? It feels to me like some electrode in the CRT isn't at the right potential. Chris |
Brian