I'm looking to resolve the jailbars on my Sega Master System Model 1.
I have my SMS Model 1 hooked up through a gscartsw_lite, into a Framemeister, and then to my TV.
I understand there is an RGB Bypass available, but it uses a THS7314 with a low pass filter. And given that I run my setup through a Framemeister, I don't want to double up on low pass filters.
Can anyone on these forums tells me what is causing the jailbars? Is it interference from circuitry in the console? If so, can this be resolved by cutting unnecessary circuitry like composite video? Would a cap replacement help?
Any and all suggestions would be welcome.
SMS Jailbars Solution
Re: SMS Jailbars Solution
What I've done 'till now:
1) Used a THS7374 RGB bypass
2) Disabled CVBS
3) Disabled subcarrier
4) Did not recap the console
Unfortunately, jailbars are still there...
1) Used a THS7374 RGB bypass
2) Disabled CVBS
3) Disabled subcarrier
4) Did not recap the console
Unfortunately, jailbars are still there...
Re: SMS Jailbars Solution
I have done a full recap and can confirm it does not resolve the jail bars.
Using a scart cable with csync did minimize them, but they are still visible in solid blue color backgrounds.
Using a scart cable with csync did minimize them, but they are still visible in solid blue color backgrounds.
-
cr4zymanz0r
- Posts: 356
- Joined: Sat Oct 19, 2013 6:36 am
Re: SMS Jailbars Solution
Did you disconnect or cut the traces for the RGBs signals coming out of the Sega 315-5124 chip so they were only connected to the RGB bypass board and not still connected to the SMS board?zeruel85 wrote:What I've done 'till now:
1) Used a THS7374 RGB bypass
2) Disabled CVBS
3) Disabled subcarrier
4) Did not recap the console
Unfortunately, jailbars are still there...
Re: SMS Jailbars Solution
This is what worked for me. I did the RGB bypass mod, and cut the signals. No more jailbars on my SMS.cr4zymanz0r wrote:Did you disconnect or cut the traces for the RGBs signals coming out of the Sega 315-5124 chip so they were only connected to the RGB bypass board and not still connected to the SMS board?zeruel85 wrote:What I've done 'till now:
1) Used a THS7374 RGB bypass
2) Disabled CVBS
3) Disabled subcarrier
4) Did not recap the console
Unfortunately, jailbars are still there...
Re: SMS Jailbars Solution
Disconnected. I will try to cut the trace when I have some free time and I'll report back.cr4zymanz0r wrote:Did you disconnect or cut the traces for the RGBs signals coming out of the Sega 315-5124 chip so they were only connected to the RGB bypass board and not still connected to the SMS board?zeruel85 wrote:What I've done 'till now:
1) Used a THS7374 RGB bypass
2) Disabled CVBS
3) Disabled subcarrier
4) Did not recap the console
Unfortunately, jailbars are still there...
Thanks
Re: SMS Jailbars Solution
I appreciate the feedback from everyone. It sounds like gaming community is still trying to figure this one out.
-
cr4zymanz0r
- Posts: 356
- Joined: Sat Oct 19, 2013 6:36 am
Re: SMS Jailbars Solution
Last night I installed a RGB bypass board for my SMS. It was better, but not perfect. Here are my results:
Before: Couldn't really see the jailbars on a 27" Trinitron modded for RGB, but they were VERY obvious on my HDTV via OSSC.
After RGB Bypass, original RGB traces NOT cut: It definately was better. The jailbars were still there but much more faint on the OSSC. I could see them up close, but could hardly tell when sitting a few feet back on the couch.
RGB Bypass, original RGB traces cut: Oddly, this didn't seem to change anything over the traces not being cut (at least as far as I could tell).
I'm much happier with it now, but the perfectionist in me is still annoyed . I'm beginning to wonder if some (all?) Master Systems have a design flaw similar to PC-Engine where there's not enough capacitance on the power filtering circuit for one of the video related chips. Investigating that is beyond my level of expertise, but I'd be happy to work with someone who does have the knowledge.
Before: Couldn't really see the jailbars on a 27" Trinitron modded for RGB, but they were VERY obvious on my HDTV via OSSC.
After RGB Bypass, original RGB traces NOT cut: It definately was better. The jailbars were still there but much more faint on the OSSC. I could see them up close, but could hardly tell when sitting a few feet back on the couch.
RGB Bypass, original RGB traces cut: Oddly, this didn't seem to change anything over the traces not being cut (at least as far as I could tell).
I'm much happier with it now, but the perfectionist in me is still annoyed . I'm beginning to wonder if some (all?) Master Systems have a design flaw similar to PC-Engine where there's not enough capacitance on the power filtering circuit for one of the video related chips. Investigating that is beyond my level of expertise, but I'd be happy to work with someone who does have the knowledge.
Re: SMS Jailbars Solution
I don't know which bypass amp RetroRGB was selling back in early 2016, but that bypass amp, along with cutting the RGB traces worked really well for me. Mine were SUPER bad before that and like 99.5% gone after that.
-
cr4zymanz0r
- Posts: 356
- Joined: Sat Oct 19, 2013 6:36 am
Re: SMS Jailbars Solution
Johnpv wrote:I don't know which bypass amp RetroRGB was selling back in early 2016, but that bypass amp, along with cutting the RGB traces worked really well for me. Mine were SUPER bad before that and like 99.5% gone after that.
I couldn't find one for sale anywhere so I ended up just ordering the PCB and populating it myself: https://oshpark.com/shared_projects/KiETPmh8
I wouldn't say 99.5% of the jailbars are gone for me though. maybe like 80% gone. There's a few different internal revisions of SMS that might affect things too.