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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment. |
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1st May 2015, 8:43 pm | #1 |
Retired Dormant Member
Join Date: Apr 2015
Location: Leicestershire, UK.
Posts: 14
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Acorn AKF-12 monitor
Hi all.
A couple of years ago I picked up a full acorn A3000 setup, including an AKF-12 colour monitor. Unfortunately the monitor has recently failed. When switched on, the power light does not come on and no picture is produced at all. All that happens now is a high pitched squeal (different to the squeal it would normally produce in operation) is produced. When the monitor is switched off this noise gradually decreases in pitch before going silent. Does anybody know what the problem might be and how I might go about fixing it? Many thanks Liam M6BWJ |
1st May 2015, 11:23 pm | #2 |
Octode
Join Date: Jan 2013
Location: Barnsley, South Yorkshire, UK.
Posts: 1,517
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Re: Acorn AKF-12 monitor
It could be all manner of things but I'd put Line Output and/or power supply problems high on the list. Given CRT computer monitors are now virtually worthless would it not be easier to just get another monitor? or do you want the actual 'badged' monitor? If you can't find an actual badged one but could live with one of the correct appearance & vintage have a look for Philips CM8833 it was a popular and reliable monitor of that era and there's one on E-bay at the moment - if you fancy it just make sure it has the correct type of inputs you require.
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2nd May 2015, 12:11 pm | #3 |
Retired Dormant Member
Join Date: Apr 2015
Location: Leicestershire, UK.
Posts: 14
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Re: Acorn AKF-12 monitor
I think I may just do that. I've never attempted servicing a modern(ish) CRT display and I really don't think it's worth my time. Unfortunate but these things happen I suppose.
On the bright side, it's an ideal unit for spares now. Many thanks |
6th May 2015, 2:46 pm | #4 |
Heptode
Join Date: Nov 2008
Location: North Walsham, Norfolk, UK.
Posts: 900
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Re: Acorn AKF-12 monitor
Pop the back off and look for dry joints especially round the the line and SMPS transformers as the steadily decreasing whistle sounds like there's no load on the PSU.
Worth a try before you bin it. |
6th May 2015, 3:03 pm | #5 |
Nonode
Join Date: Oct 2008
Location: Warsaw, Poland and Cambridge, UK
Posts: 2,677
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Re: Acorn AKF-12 monitor
The AKF12 *is*, I believe, a rebadged Philips CM8833. As such, it's becoming more and more desirable - high-quality CRT computer monitors capable of scanning at 15kHz are gradually dying out. It's worth saving if you can. There should be lots of information on line about the CM8833 because it was used with loads of computers of the era - the BBC Micro, Archimedes and Amiga for a start.
Chris
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6th May 2015, 8:34 pm | #6 |
Nonode
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
Posts: 2,573
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Re: Acorn AKF-12 monitor
The service manual for the CM8833 is readily available, just google CM8833 service manual.
As mentioned the symptoms indicate a power supply or more probably Line output fault. Keith |