I have to heat up my CRT??

It`s most likely a failed capacitor in the power supply. Unless you are confident with working on high voltage circuits, you need to take it to an engineer.

Ron(UK)

Agreed all points

Arfa

I would add solder connections to the list of suspects.

Mark Z.

Evaluate your options carefully. Professional repair costs have to be weighed against replacement costs. These days there are many many used CRTs available for very low cost or even free. This is in part due to the availability of LCD type computer monitors.

ciscodsl

Thanks for all the replies, they have been very helpful,

thanks, Rachel :)

It is common for loose connections (especially bad solder joints) to be affected by thermal expansion and contraction.

What's the connection between capacitor performance and temperature?

When electrolytics are dying through high ESR, as they often do when they approach the end of their service life - see the interesting discussions on this in thread "Which DVD player is more reliable" further down the list, started on 18th Nov by Bob Hoffman - they tend to be much worse when cold than when warm. Once you have got the cap up at enough of a temperature to get it back in spec enough for the power supply to start up, it becomes self-sustaining through self heating of the cap from the high frequency current that they tend to pass in SMPS applications, and also from radiated heat from nearby hot-running components. All is then well until next time it's left to get cold. It's the reason why so many customers bring stuff in for repair with the story that it was working fine until they went away on holiday, and shut everything down, and then the DVD / VCR / sat box / computer (sub your own equipment item) didn't ever work again when they put the power back on.

Arfa

And if you keep using it like that, further damage will eventually occur.

While I haven't looked into the actual chemistry, ESR drops as temperature rises, so bad electrolytics usually are a lot worse when cold.

I repaired a 17" CRT the other night, but really it was only because I can. Nanao Flexscan F550i, had no green. Found several leaking electrolytic capacitors on the input board with a corroded mess around them and a shorted diode in the green video amp. Good mental exercise if nothing else, the monitor looks better than it has in years.

Some component(s) in the power supply, most likely some capacitors, have become thermo sensitive. Take the monitor to a service centre for them to locate the defective part(s) and replace them.

I don't suggest for you to try to service this yourself. It takes service experience, and there are serious safety issues involved.

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JANA _____

When my monitor was working correctly, I would plug in the monitor on, the green power light would come on for a second, then it would turn amber (power down, I believe).

Now when I plug the monitor on the power light simply flashes and there is clicking noise, I have to repeatedly turn the monitor on and off at the plug switch to get it to eventually come on properly. I noticed this was worse in cold weather or in the morning when it was cold.

I tried an experiment, I placed a fan heater a couple of feet away from the monitor and switched it on for 15 minutes then turned the monitor on, It came on as normal. I've tried this a few times now, even in the morning and it comes on as normal. So when I warm my monitor up in this way it starts as normal.

I was wondering if anyone had any ideas what the problem might be.

thanks, Rachel

Yes. If you're lucky, you'll find a technician who has seen this problem before and knows exactly which part is the failure-prone one in your piece of equipment.