MegaSTE Repair Continued - Video Noise

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geogeo_28
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Re: MegaSTE Repair Continued - Video Noise

Post by geogeo_28 » Tue Jan 12, 2021 9:03 am

New picture of the noise:
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exxos
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Re: MegaSTE Repair Continued - Video Noise

Post by exxos » Tue Jan 12, 2021 4:22 pm

displaced wrote:
Thu Jan 07, 2021 12:08 am
Well, whaddya know...
Wired up a Meanwell RQ85B, and here's the output (earth connected, OSSC powered via its usual USB adapter).
BTW if that PSU is better, have you tried moving it closer to the motherboard ? Also wondering if the video is picking up interference from the PSU.. and as you have the meanwell "out" of the way... was just a thought anyway..
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Re: MegaSTE Repair Continued - Video Noise

Post by exxos » Wed Jan 13, 2021 10:55 pm

Also the problem may be on the RGB drivers .... May need better caps...

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geogeo_28
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Re: MegaSTE Repair Continued - Video Noise

Post by geogeo_28 » Thu Jan 14, 2021 5:59 am

I replaced all the caps with new ones but I should definitely test them again. I have an Atlas ESR70 to help. I have to check the diodes also.
Is it possible that the floppy controller adds noise on the bus? Definitively, I know that I have issue with this controller and it needs to be replaced.

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Re: MegaSTE Repair Continued - Video Noise

Post by exxos » Thu Jan 14, 2021 11:56 am

The whole motherboard is a noise generator..
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