Tech: CRT Monitor problems ???

Subject: RE: Tech: CRT Monitor problems ???
From: Ross Campbell
Date: 31 Jan 09 - 10:58 PM

I picked up an Apple 17" crt display for £1 on eBay last year (local collection). Great display, hopefully years of life left. If you can cope with the bulk and the weight, they still beat most TFTs for price, clarity and brightness. Similar offers for 17" & 21" monitors come up frustratingly often in the London area (I'm in Lancashire - a bit too far to make the petrol worth while!)

I have a Formac 17" crt monitor spare if it's any use (ie within reach).

Ross

Subject: RE: Tech: CRT Monitor problems ???
From: Skivee
Date: 31 Jan 09 - 08:13 PM

Sometimes it doesn't seen right to perform CPR on an old CRT; Does it have a DNR?

Subject: RE: Tech: CRT Monitor problems ???
From: Bernard
Date: 31 Jan 09 - 07:25 PM

Sounds like a dry solder joint or mucky pot to me... a dry joint can be a pig to find, but a mucky pot can be easily cured with a squirt of WD40 (whilst switched off) and quick rotation back and forth, remembering he original setting, o'course...!

Not a job for the faint hearted - especially as the HT lead to the CRT is a killer, quite literally. If you don't understand them (see JiK's post above), keep away!

An LCD 'flat screen' is definitely the way forward! They'r dirt cheap these days.

Subject: RE: Tech: CRT Monitor problems ???
From: JohnInKansas
Date: 31 Jan 09 - 01:17 PM

Be very careful if you choose to try to open up a CRT monitor to blow the dust out. The high voltage circuits inside usually contain large electrolytic capacitors that cannot be effectively discharged. After years of operation they will be charged (often at about 1500 volts) even with power off. You can (if you're quite daring) short circuit them to bring the voltage down; but just "turning things off" won't discharge them, and when the "short" is removed, without turning things back on the electrolytic "memory" will restore them to near operating voltage to zap you if you touch something.

Old CRT TVs have the same "feature."

Having gone through about a dozen computers, all but one of which was purchased with a new monitor, my experience has been that the monitors from ten or more years ago generally slightly outlasted the computer, but that has become somewhat less likely in recent years. All of our old monitors were "retained" and used again after the newest one gave out, but we finally reached the point of having no "working spares," and recently had to say fond farewell to them all. (Six of them went to the recycler in one load.)

The symptoms described are pretty much typical of "end-or-life" for a CRT. It's remotely possible that they could be caused by a failing graphics card in the computer, but about the only simple way to tell if that's the case would be to swap in a different monitor to see if you get the same result with both monitors (indicating it's probably the card) or the other one works (perhaps with a different defect if it's an old monitor) in which case it's almost certainly the monitor.

You will really like your new flat monitor. It will be much smaller and lighter, and will give the cat space to lay between it and the keyboard (or a convenient place for the bits of paper and string to pile up where they're handy). The only complaint we've found is that the cat who liked the warmth of sleeping on top of the CRT now has no place comfortable to do his cat things, and there is no longer the long tail hanging down in front to swish the dust off.

Note that the old CRT monitor is "e-waste" and should be recycled appropriately, where possible.

John

Subject: RE: Tech: CRT Monitor problems ???
From: frogprince
Date: 31 Jan 09 - 12:57 PM

Or, what could be the cheapest possible perfectly good alternative: check ebay for crt monitors. I got a 17" Compaq new in the box for about $50.00, which included shipping. There were a bunch on auction which it appears that people got in computer package deals and had no use for.

Subject: RE: Tech: CRT Monitor problems ???
From: treewind
Date: 31 Jan 09 - 12:38 PM

Get a new TFT flat screen before the old CRT gives up for ever. It's not going to last long, the replacement will probably cost less than the original did and will save you on electrical power during its lifetime.

And yes, as someone said it's probably bad contacts, either in connectors that have become dirty/tarnished with age or a dry soldered joint. But CRT monitors have high voltages and stressed components (voltage and temperature) so 9 years isn't a bad lifetime.

If you're desperate, you could try unplugging it, leaving it for a while to discharge any nasty high voltages, opening it up (this may not be easy), blowing/vacuuming the dust off all the internal parts and unplugging and re-plugging all the connectors and socketed components you can find. No guarantee it will work...

Anahata

Subject: RE: Tech: CRT Monitor problems ???
From: Newport Boy
Date: 31 Jan 09 - 12:10 PM

It sometimes works, and sometimes finally kills the device. Such problems are often due to the heating and cooling slightly disturbing components in their sockets. A sudden shock may jar them back into good contact. It may also cause the hot component to fail.

Phil

Subject: Tech: CRT Monitor problems ???
From: GUEST,punkfolkrocker
Date: 31 Jan 09 - 11:33 AM

17" CRT monitor been in reliable daily heavy use for about 9 years.
Last night the vertical hold suddenly went.
The entire 'picture' compressed down into the lower third of the screen..
After several hours of fiddling about with the controls and degaussing,
it just as suddenly snapped back into healthy condition
and started working properly again ???
Today it was working fine for about an hour
then the same problem re-occured..

so in frustration I resorted to the old method
of dealing with problematic electrical equipment
and angrily 'thumped' the top of the bloody thing.

..and by mirical and magic it immediately started working properly again !!!???


I doubt if it will last for much longer, and a replacement is soon to be purchased.

Bt why does physical violence work as such a good remedy for malfunctioning older technological devices ???