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 Post subject: 32x Video Noise
PostPosted: Thu May 10, 2018 9:32 pm 


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Joined: 05 Mar 2018
Posts: 86
I've got a Genesis 2 + Sega CD 2 combo that's working perfectly - no jailbars! - no noise of any kind, through HDRV component cables. When I connect the 32x however I get these very faint horizontal lines moving through the screen. The lines are not sharply defined, almost looks like a waterfall effect. It's fairly subtle and can be seen better on dark backgrounds.

I have all three units connected to a single 5A 12VDC switching supply that's quite nice. In an effort to troubleshoot the noise, I tried various combinations of other supplies (all SMPS, I don't have any linears in the right voltage range) and even tried isolating all three units on separate supplies in case of ground looping. The isolation seemed to make no difference, and some of the other supplies introduced other noises into the base genesis output. So I'm currently back to the single 5A supply, with the 32x disconnected, and all is well again.

What should I try to clean up the 32x output? Aftermarket video jumper cable from the base console (if there even is such a thing)? Recap? Something else?

P.S. I have another 32x (not being used) that has a much more exaggerated version of the same problem, but on it the lines are VERY noticeable and the unit emits an audible whine. Might be a more "mature" condition of the same base issue.

P.P.S. I found that if I connect the "good" 32x using the factory metal shield plate things I actually get some pretty gnarly jailbars on blue just like a model 1. This is in addition to the other noise mentioned above. Removing the shields seems to have no downside so anyone using a 32x should probably ditch them if you are suffering from jailbars on model 2.


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 Post subject: Re: 32x Video Noise
PostPosted: Thu May 10, 2018 11:29 pm 



Joined: 07 Apr 2016
Posts: 1123
Location: Ohio
I thought the 32X was supposed to make the image quality better, not worse. On Composite and RGB.


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 Post subject: Re: 32x Video Noise
PostPosted: Fri May 11, 2018 10:27 am 



Joined: 20 Mar 2017
Posts: 93
A recap can always help, just make sure if you replace all of them, CE18 is a special Sanyo os-con solid polymer cap, so if you replace that one, you'll need a Panasonic os-con, as Sanyo were bought out by them some years ago. Also, check your patch cable, it can be the case where the cable connecting the video out from the Mega Drive to the 32X can cause noise.


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 Post subject: Re: 32x Video Noise
PostPosted: Fri May 11, 2018 12:45 pm 


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Joined: 05 Mar 2018
Posts: 86
Xaranar wrote:
A recap can always help, just make sure if you replace all of them, CE18 is a special Sanyo os-con solid polymer cap, so if you replace that one, you'll need a Panasonic os-con, as Sanyo were bought out by them some years ago. Also, check your patch cable, it can be the case where the cable connecting the video out from the Mega Drive to the 32X can cause noise.

I'm not sure what to check specifically about the patch cable, it is OEM Sega and undamaged. Is there an upgraded aftermarket one available?


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 Post subject: Re: 32x Video Noise
PostPosted: Fri May 11, 2018 1:33 pm 


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Joined: 25 Dec 2013
Posts: 504
Location: Indiana
For testing isn't it possible to not use the patch cable at all and plug in directly to each output one at a time. Might help to see if the jailbars are only on one output.


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 Post subject: Re: 32x Video Noise
PostPosted: Fri May 11, 2018 1:58 pm 


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Posts: 86
citrus3000psi wrote:
For testing isn't it possible to not use the patch cable at all and plug in directly to each output one at a time. Might help to see if the jailbars are only on one output.

I did try putting a genesis cart in the 32x and NOT routing video through the unit - multi out from the genesis direct to load, 32x only receiving power. This did not introduce the noise.

I did not try a 32x game with the jumper disconnected and running 32x multi out to load, I was under the impression this would not function but I will try it tonight


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 Post subject: Re: 32x Video Noise
PostPosted: Sat May 12, 2018 3:10 pm 


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Joined: 05 Mar 2018
Posts: 86
32x game with video from genesis -> display = no interference, many objects missing
genesis game in 32x with video from genesis -> display = perfect
32x game with video from 32x -> display, no jumper = no video


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 Post subject: Re: 32x Video Noise
PostPosted: Tue May 15, 2018 10:23 pm 


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Joined: 05 Mar 2018
Posts: 86
still at a loss with this, trying to decide what to go for next

1) get a linear power supply to drive the 32x since it doesn't have a 7805 in it
2) try replacing oem sega link cable with aftermarket

thinking about going for the psu first, I don't suppose anyone knows the actual peak current draw of the thing? it's spec is 850ma but I feel like that's probably more than it needs...


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 Post subject: Re: 32x Video Noise
PostPosted: Wed May 16, 2018 5:05 am 



Joined: 03 Mar 2005
Posts: 298
maxtherabbit wrote:
1) get a linear power supply to drive the 32x since it doesn't have a 7805 in it


If the Console5 tech-wiki is accurate, then the 32X contains an RH5RL33A regulator (EDIT: The service manual confirms this). This is intriguing, because that would have it supplying only 3.3V while the SH2s and RAM apparently require 5V. Are those parts getting their power from the Genesis? I'll have to investigate.

If you go the route of getting a quality 9V SMPS, I'd go ahead and get a Y-splitter so that you're giving both the Genesis and 32X stable power. While linear regulators like the 7805 should be good at rejecting moderate levels of ripple from an AC adapter, the filter capacitors in original adapters are due to go bad sooner or later, so you might as well head off that problem now.


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 Post subject: Re: 32x Video Noise
PostPosted: Wed May 16, 2018 11:12 pm 


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Joined: 05 Mar 2018
Posts: 86
Found a suitable linear brick for the 32x and it didn't change anything :|


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