Where to get a replacement CRT

Only alternative is to get a dead CC and hope the CRT is OK.

I 'won' a CC a/b from the same seller. Same total lack of response. Let's both post -ve feedback, to protect others from him.

Stuart

Don't worry, I already posted the appropriate feedback: "Will not respond to any of my emails. Did not honour deal. Not to be trusted."
This guy had no problem replying to my questions proir to the auction ending - he even mentioned you by name Stuart and suggested that I look at this forum (which I was aware of anyway).

jms.esp

Someone to avoid ebay-wise!!

Maybe the problem with this CC is not the CRT but the video card?
Having had another look it's nowhere near as bad as I remember it being - but there is a sort of shadowy line running just to the right of centre: http://web.ukonline.co.uk/gdmorris/Classic_Screen.jpg

Could this be something to do with loose cables or poor solder joints somewhere? Maybe it needs deguassing? or is this sort of thing normal for colour crts?
I initially was thinking burnt out phosphors - hence bad CRT, but now I'm not so sure.

problem is indeed an a/b issue. In my experience, apart from screen burn, CC CRTs either work or they don't. Where are you geographically? I have a spare CC CRT in the garage, but I hate the idea of entrusting it to the PO!

Stuart

I'm in London, cityside E1. So you think from looking at the image that this shadow could be caused by the anologue board? The image is stable and sharp. The shadow is only really visible when the desktop background is grey or white - but, being the doomed perfectionist that I am, it really bugs me.

....so I should be looking for a replacement a/b instead?

One sure way would be to open up the CC, and release the yoke clamp. Rotate the yoke a little. If the fault moves, then it's probably the a/b. If the fault stays fixed, then it's probably the CRT.

a/bs are VERY hard to find.

But next time I'm going to be in EC1, I'll try to remember to let you know. If you ever head towards Southampton, you can have a CRT FOC, if it turns out that that's your problem.

Stuart

That's a good idea, I'll give it a try this weekend. Thanks for the kind offer of the CRT, which I will definitely accept, should it prove to be the problem....but knowing my luck it will be the a/b (!)
Maybe if it is the a/b a spot of joint resoldering might help? I once managed to resurrect a Mac Plus this way, maybe worth a try.

Absolutely. Start with cold joints, then leaking capacitors.

Stuart

Well, having rotated the yoke and seen the screen 'shadow' move accordingly - I have to conclude that the CRT is not to balme. I would never have thought the a/b was to blame as the image has always been very stable and noise free...but then this is a colour screen, which I suppose is more sensitive to component ageing/failure. Before I attempt to resolder the a/b board I think i'll have a go at the small video board sticking out behind the neck of the CRT. If anyone knows of any particularly sensitive video related components on the a/b i'd be very grateful for any info.

Given that CC a/b boards are highly endangered species, and that a working a/b that gives a shadow on the CRT is better than an a/b that gives nothing, do be careful! ;-)

Good luck,

Stuart

Yes, I will be VERY careful.
From what I can see of the board itself , it looks pretty grimy. One visible resistor seems to have leaked some orangy coloured liquid. I've done some searching around various forums, but there doesn't seem to be an obvious answer to what is causing the (arcing to the right) shadow.

Keeping Stuart's caveat about taking care against breakage well in mind, pay close attention to the soldering of the pins connecting the video board and CRT. Use fresh solder rather than a remelt if the soldering is suspect. Tarnish, from slight to pronounced, needs cleaning off (both pins and receptacle). Look also for molten plastic from overheated pins, caused by arcing within the connector. From there, look for molten cable jackets (same cause). Cast a jaundiced eye also over the connection of the loom to the a/b, breaking and remaking it two or three times.