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

[leonk]

Put together by Tim W of NESRGB fame himself!!

http://etim.net.au/av-driver/pcebars/

[MNKyDeth]

Bookmarked for the next time I work on one of these consoles.

I use an XRGB though and have never experienced this jailbar effect with any of the ones I personally own with it. Maybe it is more pronounced on actual RGB TV's?

[turbokon]

Awesome, this is exactly what we needed.  I have an ifu white pce setup I rgb modded.  I tried all the previous known methods to get rid of the jailbars to no avail.  I will try this tonight.

[SegaSonic91]

So, Tim finally put up some info in regards to the AV Driver.  I am still waiting for that thing to appear in the shop section.  Shame he does not do repairs, I could use an expert like him to fix my DUO-RX

[mickcris]

Hopefully this is the universal fix. The other methods seem to work on some consoles and not others.

[MotherGunner]

Agreed.  I could use this fix on my TG-16.  Also, the US Duo I have had slight jail bars for even standard AV.

[turbokon]

It definitely help my ifu pce setup.  I ended up going with 10uf caps.  Also someone might tell him he mixed up the pce and turbografx board.

[Keith Courage]

Yeah, so far every system seems to act a little different with RGB. Just last week I installed an amp in a pcengine IFU setup and it had no jail bars whatsoever. I didn't even do any of the cap additions or changes. All I did was take everything needed from the exp port pins inside the IFU. I used C-sync, not composite video for sync.

It's too bad we can't just toss one of these inside our consoles to fix everything.

[Ergot_Cholera]

This looks promising. I have ordered some of the 1206 size as I found them cheaper than the 0805.
 As others have stated the "fixes" seem to work better on some consoles than others. I replaced C103 on a PC Engine with a 470uF and the jailbars were reduced a lot, tried it on another and it didn't seem to have any effect.

[thesteve]

in this he is adding capacitance to A5V and D5V lines
my pin41 and pin43 is A5V and Aref-low
the A5V is consistent with his thought process but the ref-low was done because the amps use 0v for ground, but the6260 outputs are using ref-low as signal ground for the DA canverter

[wilykat]

What about Duo-R? I can't find 2 sets of 4 caps near the video chip unless it is that 2 banks of 4 electrolytic caps to the right of the chip C954 to C960?  The negative leads all connected to ground (no separation) and all positive leads goes to various spots mostly under the video chip.

[leonk]

Parts came in from Digikey and I gave it a shot.  OMG for the first time, my Turbografx-16 is CLEAN.  Can't see any jailbars at all!! 

Here's the part I ordered:

http://www.digikey.com/product-search/en?keywords=445-2873-ND

I desoldered/removed the through hole caps and used these in its place.  For other systems, here's the SMD equivalent:

http://www.digikey.com/product-search/en?keywords=1276-2873-1-ND

[mickcris]

This is the location on the Duo-R.  They are on the underside of the board opposite of the HuC6260.  They have the same number designations as the regular Duo.

[SegaSonic91]

Definitely trying this one the DUO when I get the caps replaced.  The IFU I am doing has a Core Grafx with the CD-ROM2.  The IFU system I bought waaaaaaay back in 1995 was an original white PCE so I will interested in seeing if there is any difference, video wise between the two.  I keep reading that the white PCE gives jailbar free RGB in the IFU,

[wilykat]

Thankies for the image, it wasn't obvious to me because the chip were kind of scattered. I didn't think to check the part reference number and see if it had the same wiring diagram.

Since my Duo-R is out for the modding, I might as well do this.  It won't hurt to have one beefier cap on each rail at all and I have quite a few caps.  I think... 22uF ceramic cap (package size 1210 or metric 3225) is probably overkill but it's got to be a whole lot better than the feeble sized stock caps NEC used.