PC Engine 'Jail Bar' Video Noise - repair guide by Tim W

[Keith Courage]

Didn't do anything wrong. Followed the guide to the letter. I am not questioning the ability of Tim as I assume he is a professional electrical engineer and certainly more knowledgeable and capable with electronics than I am. 
The consoles are RGB modified using THS7314 ICs and the output is via shielded scart cables straight to a TV (I'm in Europe).

Give this a try.
 I just did this extra capacitor mod for a JP PC Engine DUO. It works great. No jail bars whatsoever now. Just installed the one larger cap in the picture. Website did not say the value of the capacitor but from the length/width of it I'm guessing that it's a 820UF or 1000UF cap. I haven't seen many lower value caps that are that tall and skinny.





Adding this 1000UF cap is the only thing I changed. Did not have to add the two 22uf caps nor did I have to do anything extra with grounding.

Also, did you try using pure sync instead of composite video for sync?

[Ergot_Cholera]

Didn't do anything wrong. Followed the guide to the letter. I am not questioning the ability of Tim as I assume he is a professional electrical engineer and certainly more knowledgeable and capable with electronics than I am. 
The consoles are RGB modified using THS7314 ICs and the output is via shielded scart cables straight to a TV (I'm in Europe).

Give this a try.
 I just did this extra capacitor mod for a JP PC Engine DUO. It works great. No jail bars whatsoever now. Just installed the one larger cap in the picture. Website did not say the value of the capacitor but from the length/width of it I'm guessing that it's a 820UF or 1000UF cap. I haven't seen many lower value caps that are that tall and skinny.





Adding this 1000UF cap is the only thing I changed. Did not have to add the two 22uf caps nor did I have to do anything extra with grounding.

Also, did you try using pure sync instead of composite video for sync?

I tried the capacitor that you suggested on a Duo that I used to own a while ago (since sold as I prefer the SCD-ROM²) and it does indeed work. I used the only spare large, brown coloured capacitor that I had (think it was 820uF).

The Core Grafx is a different story though, I have tried the two 22uF caps from the C6260 and it made no difference. I might have to try using pure sync, instead of cutting the trace to the pin on the din 8 it would be less destructive to just remove the 470uF cap next to it wouldn't it?

[Keith Courage]

yes, you can remove that capacitor to do what you are talking about. The reason most people like to cut it is so that way they can install a switch on the system to then swap between regular composite video and pure sync.

sorry, didn't realize you were talking about a core grafx earlier.

[mickcris]

I have had one coregrafx that had jailbars that were so bad that I could really notice.  i tried using c-sync on that console and it made no difference.  Also the 22uf caps on the c6260 also made no difference.  this was before Tim's fix so im not sure if that would have helped on this console or not.

[Ergot_Cholera]

I have noticed that Core Grafx seem to be the worst for jailbars followed closely by the Duo, don't know about Duo-R/RX as I have never owned one. I had a shuttle that had fairly bad jailbars, probably on a par with Core Grafx.
I think the best is the original PC Engine. I tried this "fix" on an original without any other mods using an RGB modded AV Booster and then on my SCD-ROM², with the AV Booster they are still slightly visible but on the SCD-ROM² I cannot see any (this is using comp video as sync).

[deubeul]

I Just replaced C133 and C135 on a white PcE that had huge jailbars after I RGB modded it, and they totally disapeared!

[ApolloBoy]

Just swapped out the S-video mod in my white PCE for an RGB mod yesterday, and I went and performed Tim's jailbar fix while I was in there. No jailbars to speak of.

[Keith Courage]

After many more systems and testing the 4.7uf fix by adding two of them to the necessary cap spots, it has worked on at least 95% of the systems I have applied it to. This guide by Tim should really be stickied as the definitive way to remove jail bars. Works better than anything I've ever done in the past.

So besides the initial guide http://etim.net.au/av-driver/pcebars/

one should also add the pics that mckcris posted for the core grafx and DUO-R

[NightWolve]

Cool to hear. Saw the date just now, he put that guide together only a month ago, so it's really new information. Looks like Le Steve has serious competition for PCE problem-solving.

[thesteve]

funny thing is this one isnt really different from mine, except i went directly to the pins

[wilykat]

I did my mod a while back, forgot to take pictures.  I got a few 22uF cap in SMD size 1210 (1.2mm by 1.0mm)  It is noticeably larger than existing SMD but I was able to place the new cap side by side with existing cap and solder em together. No messy wires, no need to remove old cap, etc. and 1210 is plenty big enough for most people to hand solder it, no solder paste or baking the board.

[Keith Courage]

funny thing is this one isnt really different from mine, except i went directly to the pins

I was actually wondering this exact same thing. on the first couple of systems I tested it on I just thought nothing of it. Thinking, well how could it be any different? but then I noticed more and more systems with the same results. All I can say is that in some systems that I've done the 22uf capacitor fix, the 4.7 UF fix in the other places just worked better.

[mickcris]

yeah for whatever reason, the 22uf fix only seemed to work on duos.  this 4.7uf seems to work on all versions.

[gojira1954]

Anyone done a supergrafx yet? I would like to know which caps to replace pls =]

[Ergot_Cholera]

Anyone done a supergrafx yet? I would like to know which caps to replace pls =]

I have RGB modded my Super Grafx and I really can't see any jailbars without the jailbar fix. Others may have a different result though I suppose.
Maybe Super Grafx are less prone to jailbars due to the layout of the board.