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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: 82atari5200 on November 14, 2010, 01:28:49 AM

Title: commodore 1084 repair
Post by: 82atari5200 on November 14, 2010, 01:28:49 AM
I have 3 1084's that all flicker after being on for a few minutes plus a 1092? that does it every once in awhile. one of the 1084's picture stretches at the top but looks normal otherwise I'm handy with a soldering iron and have built/fixed various other electronics but can't find a troubleshooting guide for these monitors anywhere.  Any help would be much appreciated...
Title: Re: commodore 1084 repair
Post by: Franko on November 14, 2010, 01:39:39 AM
See DLH's site for the 1084 service manual & lot's of other great info as well... :)

DLH's Site: 1084 Service Manual (http://www.bombjack.org/commodore/commodore/)
Title: Re: commodore 1084 repair
Post by: mechy on November 14, 2010, 04:48:55 AM
Most the time its cracked/cold solder joints on the flyback transformer.The 1942 is notorious for having the chokes soldered badly and flyback solder thats bad..other times may be a flyback thats arcing. there are other causes,but these i have seen alot.

Sadly most people run them glitching and smack the hell out of them to attempt to make them act right until it either kills the fets/transformer or burns something up. I was given a old 1960 multisync that had a 1/2" hole burned thru the board in the middle and the fet literally crumbled to dust when i went to remove it.Being a crazy fool who hates to toss anything,i made a attempt at fixing it,and I managed to get this monitor going,but still has bad 15khz screen,oddly works perfect on 31khz..oh well can't win them all ;)  as usual BEWARE OF THE HIGH VOLTAGES INSIDE!

Btw,i guess u meant a 1902(c64 monitor?) they have the same troubles usually.

mike
Title: Re: commodore 1084 repair
Post by: 82atari5200 on November 14, 2010, 10:08:43 PM
Now I only have a solid line in the middle of the screen. But it no longer flickers. :)
Title: Re: commodore 1084 repair
Post by: tone007 on November 14, 2010, 10:10:32 PM
Sounds like you gave it a good beating!

Next step, dumpster!
Title: Re: commodore 1084 repair
Post by: Tenacious on November 14, 2010, 10:48:20 PM
Quote from: 82atari5200;591767
Now I only have a solid line in the middle of the screen. But it no longer flickers. :)

I'd be willing to bet this is one the most common failures.  I have a 1084s and a 1950 that do this.  Haven't gotten around to repairing them yet.

If I understand correctly, your entire screen is concentrated in that horizontal line.

@ tone

What day of the week is your garbage collected?  You seem to pitch anything.
Title: Re: commodore 1084 repair
Post by: 82atari5200 on November 14, 2010, 10:53:29 PM
Yes. I think it is. It was working before but I took it apart and reflowed the solder and when I put it back and turned it on there was only the center line.
Title: Re: commodore 1084 repair
Post by: Franko on November 14, 2010, 11:48:28 PM
That means the line fields collapsed, could be a number of different causes and not easy to fix if you don't have the tools and know what your doing... :(

(could end up being a costly repair too... :( )
Title: Re: commodore 1084 repair
Post by: 82atari5200 on November 14, 2010, 11:59:52 PM
Well looking around it looks like the i301 vertical ic is bad. Anyone else concur?
Title: Re: commodore 1084 repair
Post by: actung_bab on November 15, 2010, 12:09:54 AM
Quote from: 82atari5200;591567
I have 3 1084's that all flicker after being on for a few minutes plus a 1092? that does it every once in awhile. one of the 1084's picture stretches at the top but looks normal otherwise I'm handy with a soldering iron and have built/fixed various other electronics but can't find a troubleshooting guide for these monitors anywhere.  Any help would be much appreciated...
just be very very carefull as like other poster said there some serious voltage my best freind got nasty zap from monitor and he is quilifed service technician
his father was tv repair man and he got caught out as well .
give you very nasty shock not pleastant at all as capittors can store volatge for long time as well . if you want work on at least leave 24 hrs not switched on have somoone with you
tv service shop maybe better option
Title: Re: commodore 1084 repair
Post by: 82atari5200 on November 15, 2010, 12:19:37 AM
I found that one out a few years ago replacing some mac classic monitors. My arm ached for a day.
Title: Re: commodore 1084 repair
Post by: tone007 on November 15, 2010, 12:22:32 AM
Quote from: 82atari5200;591808
I found that one out a few years ago replacing some mac classic monitors. My arm ached for a day.


..and this is why I'm more than happy to toss them when they give me trouble!
Title: Re: commodore 1084 repair
Post by: RobertB on November 15, 2010, 03:45:35 AM
If you can afford the postage, send it to master repair technician, Ray Carlsen, in Washington state.  He can repair such a monitor.

How many of our club monitors have been repaired by him?
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug
The Other Group of Amigoids
http://www.calweb.com/~rabel1/
Southern California Commodore & Amiga Network
http://www.sccaners.org
Title: Re: commodore 1084 repair
Post by: mechy on November 15, 2010, 06:54:47 AM
Quote from: 82atari5200;591801
Well looking around it looks like the i301 vertical ic is bad. Anyone else concur?


that is sure a possibility, but it makes me ask what caused it to fail suddenly?,you may have other problems causing it and adding another vertical ic may just fry again..soldering the flyback etc shouldn't do that? u kill it with static or just a fluke it died? you bridge some solder somewhere that shorted it?
I really don't know enough about monitor repair to help much.

As robertB said,ray carlsen is a good guy,you might email and ask some questions,he's pretty friendly.

Mike