Commodore 1084D Flyback Question

[RNSpeed]

My Commodore 1084 is having some upper screen distortion problem described on the following thread http://amiga.org/forums/showthread.php?t=72748.

Factory flyback is MSH1FCT81 (see pic #1). So looking on different pages with references for replacement LOPT one of the listed ones is MSH1FCT31 (pic #2). So as part of the troubleshooting process I ordered the replacement LOPT and once installed when I turn on the monitor it powers on for a second then power off.

Had tried two different MSH1FCT31 and got the same results. It the MSH1FCT31 really a replacement for the Commodore 1084D?

[spaceman88]

They both seem to cross to a HR 46045. I haven't changed a 1084D flyback so I don't know for sure, but I have used replacement flybacks before with (mostly) good results. I did run into one TV that had issues with a replacement. Did you try the original back in it to see if it still works? When I first looked at your pictures I thought it might be a capacitor, but your problem gets worse when when it warms up, bad capacitors usually get better as they warm. Maybe a yoke? But with that you most often get bending on both sides of the screen. Then there's the whole PAL/NTSC factor, definitely a weird one.....if I think of something more helpful I'll come back, good luck.

BTW, since it gets worse when it warms up, did you try any freeze spray to cool selected parts?

[UberFreak]

Definitely not a flyback issue.

Btw, in the other thread you posted RGB pictures that look fine.
Are all the pictures 50Hz or 60Hz, or are they mixed?
Its not clear from the description, since later on you write that PAL (50Hz) looks fine on composite.

As spaceman88 suggested, get a freeze spray, let the monitor warm up and start exploring.
I'd start with the PSU, then move to the HV section.

[RNSpeed]

They both seem to cross to a HR 46045. I haven't changed a 1084D flyback so I don't know for sure, but I have used replacement flybacks before with (mostly) good results. I did run into one TV that had issues with a replacement. Did you try the original back in it to see if it still works? When I first looked at your pictures I thought it might be a capacitor, but your problem gets worse when when it warms up, bad capacitors usually get better as they warm. Maybe a yoke? But with that you most often get bending on both sides of the screen. Then there's the whole PAL/NTSC factor, definitely a weird one.....if I think of something more helpful I'll come back, good luck.

BTW, since it gets worse when it warms up, did you try any freeze spray to cool selected parts?

Thanks for the information. With the original Flyback the monitor works, and with the replacement which I had already tried two  with the same issue of the momentary On/Off behavior

[RNSpeed]

Definitely not a flyback issue.

Btw, in the other thread you posted RGB pictures that look fine.
Are all the pictures 50Hz or 60Hz, or are they mixed?
Its not clear from the description, since later on you write that PAL (50Hz) looks fine on composite.

As spaceman88 suggested, get a freeze spray, let the monitor warm up and start exploring.
I'd start with the PSU, then move to the HV section.

Thanks for your reply. The monitor works without issues with a PAL (50Hz) Amiga A1200. I had tried RGB, and composite and the monitor works without issues.

But any NTSC source which  I had tried with my other Amiga A1200 (that is NTSC) RGB and composite the monitor gets the distortion (starting from the TOP bending to the left) and getting worse the more time the monitor stays on.

Other NTSC sources I had tried with the same Results; Turbografx, Supergrafx, PC Engine, PSX, Sega Genesis.