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

[leonk]

Put together by Tim Worthington of NESRGB fame himself!!

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.

[leonk]

The biggest issue is would it fit on the pads. Don't want the caps to be too big.

[Corredor X]

I keep reading that the white PCE gives jailbar free RGB in the IFU

Sadly that's not always the case, my RGB modded white PCE gives me jailbars on a IFU  They are visible in places like Keith Courage's blue sky and Bomberman/Bonk 3 title screens. Looking forward to do viletim's mod too, saw it on Shmups forums and the results look amazing for a very simple procedure; before that I was wondering if modding the IFU could get me a better image.

[SegaSonic91]

I keep reading that the white PCE gives jailbar free RGB in the IFU

Sadly that's not always the case, my RGB modded white PCE gives me jailbars on a IFU  They are visible in places like Keith Courage's blue sky and Bomberman/Bonk 3 title screens. Looking forward to do viletim's mod too, saw it on Shmups forums and the results look amazing for a very simple procedure; before that I was wondering if modding the IFU could get me a better image.

That's disappointing.  But in saying that, it seems that nothing is ever 100% the same with this wacky system.  Some people report no jailbars with a Core Grafx while others say it's terrible.  Same can be said with just about every other iteration, save the US versions, it seems.  I am STILL waiting for my power cables for both my IFU and DUO (which I finally finished capping today) to arrive before I can test them out.  I am not impressed with "Retro Game Suuplies" service, at all. 

I do not have Wataru yet (been meaning to buy it for years!!) or PC Genjin 3 to test with, what games are good to test for jailbars?  I think I've seen Super Raiden used before, I can use that.  Legend of Hero Tonma has quite a lot of blue backgrounds from memory, I may try that, too.  Although, I don't remember full solid backgrounds, it tends to have more going on in the background.

One other thing I was wondering, does the Super Grafx suffer from jailbars, too?

[incrediblehark]

my white pce+ifu30 has perfect picture without this mod, but my duo could use it for sure. just don't know how comfortable i feel about doing it myself.

[mickcris]

location on the CoreGrafx.  They have the same part ids as the white PCE

[incrediblehark]

Got my caps in the mail today from digikey, the smd ones leonk linked to. Man these are small! I'm going to give it a shot but worried I'm going to kill my duo.

[L-Digital]

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.

Hi Keith

Do you have a guide you can point me to for getting c-sync when modding the if unit? Do you use an amp or just channel it from the pins to the output?

Thanks

[Keith Courage]

Here is a pic of the pin out inside an IFU. Use the pin labeled sync. Do not use composite video.



Then wire up your Din port like this. Pic is from a DUO but the pin out should be the same.



Although there are many who prefer that the red and blue lines be swapped around. Either way works as long as you wire up your scart cable accordingly.

[NightWolve]

Great find, the guide was put together and presented well! Him and Steve have never talked on each others' findings but oh well. Will be interesting to see if this works better than everything we have reported here.

[incrediblehark]

EDIT: The following post appears to be unrelated to the jailbar issue, new thread to be started as I don't want to mislead others looking for what seems to be a reliable fix for jailbars

So I installed the 2 caps per viletim's instructions and the jailbars are gone! I have to say I did a pretty terrible job of soldering these to the board but it seems to have worked. However, I am still having another issue. I am getting a lot of interference on screen in the form of diagonal wavy lines. I tried taking pics of it:


It appears as snow in the photos, best I could do to capture them. This issue was ongoing for me even before the fix, and I was hoping this would clear it up. Any idea on what could solve this issue? its the only thing holding me back from a clear picture on my Duo.

[ApolloBoy]

What kind of power supply are using with your Duo? If you're using a cheap PSU it can generate interference like the kind you're seeing.

[incrediblehark]

It is an official US Duo adapter. I could try a newer one but would have to get a tip for my universal.

[NightWolve]

The original is an el cheapo unregulated model, yeah, I would upgrade it quick. Might as well give less work to the internal regulators.

https://www.pcengine-fx.com/forums/index.php?msg=374635

You want a 9 VDC adapter preferably rated at/above 1.5 Amps. You can go 1 volt lower per Steve's findings/recommendations. I have a link on where to buy a tip in that post as well.

[deubeul]

Did you have the diagonal wavy lines before you put the 2 caps?

I had  diagonal wavy lines on 2 CGX too. At first I assumed it was because of the RGB amp I used ( a homemade Sodipeng amp), because a Duo-R with Pnauts' amp did not have the problem.

I tried the CGXs with others PSUs, even an other TV, but problem was still there. I even tried with a different kind of  din8 base in one of the CGX.

I also tried to get the RGB from the Huc6260, since I get it from there in the Duo, but no difference.

Then I received everything needed to build a Micro's amp and the diag lines were still there. Note that I replaced C135 and C133 with the 4.7 uF on this CGX. Let's call it CGX1.

Then I desoldered the Pnaut's amp to put it in the other CGX, the CGX2 then, and the diag lines were still there. What the fuck?, did I say to myself.

Then I noticed the wires I used in the CGX1 for the RGB mod were not the same I used for the Duo-R. So I desoldered the wires and replaced them with the same I used with the Duo and BAM! Bye bye the diagonal wavy lines.

Problem was still there on the CGX2 with Pnauts' amp though. Goog wires, good amp, good PSU, good Din8 base, same Scart cable, same psu. What the hell was the problem? What's the difference with the CGX1? Answer was: C133 and C135 replacement. Now the picture is just perfect, freed from jailbars and  diagonal lines.

In these cases the issue was a combination of severeral little things. Maybe my handmade Sodipeng amp would work now? But hey, I'm tired of soldering/desoldering for today. Tomorrow I'll see if the diagonal lines come back if if get the RGB from the exp port and let you know.

[mickcris]

The original is an el cheapo unregulated model, yeah, I would upgrade it quick. Might as well give less work to the internal regulators.

https://www.pcengine-fx.com/forums/index.php?topic=14453.msg374635#msg374635

You want a 9 VDC adapter preferably rated at/above 1.5 Amps. You can go 1 volt lower per Steve's findings/recommendations. I have a link on where to buy a tip in that post as well.

these adapters are easier to use as no soldering required:
http://www.ebay.com/itm/DC-Power-Plug-Jack-Change-Adapter-3-0x6-3mm-Male-to-2-1x5-5mm-Female-lot-/131665973582

Im not really sure those cheap chinese supplies are better than the original though.  Some can cause noise in the picture.

[incrediblehark]

Thanks for the input to everyone who responded. To answer some questions:

NightWolve  - I have an enercell universal adapter I use on my ifu-30 which is also rgb modded. I just ordered a "Q" style tip to see if it will clear up the issues on my Duo. My IFU-30 has the same amp and uses the same cable.

deubeul - The lines were there before I replaced the 2 caps. It is a US Duo. it is using the same amp as my ifu-30, and I believe I used the same gauge wire (ifu-30 was a homemade project, duo was a commissioned mod). the briefcase setup has no lines, and the rgb was taken from the expansion port.

You said you replaced C135 and C133 on the coregrafx? Do you know what that would translate to on a duo? not that I trust my soldering skills... I'm too embarrassed to show just how bad of a job I did on this replacement. (crooked caps)

[NightWolve]

The original is an el cheapo unregulated model, yeah, I would upgrade it quick. Might as well give less work to the internal regulators.

https://www.pcengine-fx.com/forums/index.php?topic=14453.msg374635#msg374635
You want a 9 VDC adapter preferably rated at/above 1.5 Amps. You can go 1 volt lower per Steve's findings/recommendations. I have a link on where to buy a tip in that post as well.

these adapters are easier to use as no soldering required:
http://www.ebay.com/itm/DC-Power-Plug-Jack-Change-Adapter-3-0x6-3mm-Male-to-2-1x5-5mm-Female-lot-/131665973582

Im not really sure those cheap chinese supplies are better than the original though.  Some can cause noise in the picture.

The original is also a cheap supply from Taiwan, but cheaper in every way. Just a super-sized dry-transformer, 4 diodes, one 10,000 uF smoothing capacitor, and a one-time fuse, that's it... A 9 volt regulated model would give a bit less work to the internal regulators and is better for the motor area which is fed the full unregulated power per Steve's findings. It's entirely better on paper to get a regulated model and if you do get noise, to find another.

[mickcris]

The original is an el cheapo unregulated model, yeah, I would upgrade it quick. Might as well give less work to the internal regulators.

https://www.pcengine-fx.com/forums/index.php?topic=14453.msg374635#msg374635
You want a 9 VDC adapter preferably rated at/above 1.5 Amps. You can go 1 volt lower per Steve's findings/recommendations. I have a link on where to buy a tip in that post as well.

these adapters are easier to use as no soldering required:
http://www.ebay.com/itm/DC-Power-Plug-Jack-Change-Adapter-3-0x6-3mm-Male-to-2-1x5-5mm-Female-lot-/131665973582

Im not really sure those cheap chinese supplies are better than the original though.  Some can cause noise in the picture.

The original is also a cheap supply from Taiwan, but cheaper in every way. Just a super-sized dry-transformer, 4 diodes, one 10,000 uF smoothing capacitor, and a one-time fuse, that's it... A 9 volt regulated model would give a bit less work to the internal regulators and is better for the motor area which is fed the full unregulated power per Steve's findings. It's entirely better on paper to get a regulated model and if you do get noise, to find another.

I personally have never had an issue with an original supply causing noise but im not saying it cant happen.  I have however had lot of issues with those power supplies from china.  They have flooded the market with them though so its hard to find a good quality one these days.  People from the US buy them for a couple bucks and sell them here for $10 or more to make it look like they are better quality when they are the same.  You just have to be prepared to toss it if you buy one and try again like you said. 
They also sometimes overstate the max current rating so that is something else to be aware of.  If you ever open one up, you will see how junky they are.

[thesteve]

i use the cheap china supply's and other then having a few fail they have been good
never really had a noise issue with them
that and for less then $3 having a bad one from time to time isnt a big deal

[mickcris]

i use the cheap china supply's and other then having a few fail they have been good
never really had a noise issue with them
that and for less then $3 having a bad one from time to time isnt a big deal

I bought a 10 pack from alliexpress a couple weeks ago as I was living dangerously and they showed up yesterday.  The one I tested seems to work pretty well with no noise so that's something.  I still wish there were some relatively cheap ones that were a little better quality.  The ones I got yesterday are a little heavier than the ones I had previously but they still feel cheap.

Just a warning on these universal ones as they are terrible and cause noise interference:
http://www.amazon.com/Nippon-America-2000mA-Multi-Purpose-Adapter/dp/B00EZB5OTM

[Fidde_se]

Tested it on the CoreGrafx I mostly used and it has some jailbars and I have la steve fix on it which made it a little better, tried Tims, and made no difference.

Used the new Banding test, https://dl.dropboxusercontent.com/u/1403041/banding.pce

Tested TG16 without any jailbar mods, and it was nearly invisible, tried a white PCE and it was not showing at all at stills, some less visible more like dreamy maybe when the orange moving squares was showing in the banding test, was struck by that those two didn't show anything when a double modded CG showed it....

But then again, 100nF should be enough on the rails, it's the most common capacitor value just because of the function it has, between a line or vcc to ground... and it's used for it's filter function
so the value actually has to be precise, but first you must know signalwise, what it is you want to remove, what we want to do is not much different from a speaker crossover but we don't know the "jailbars" frequency and not input or output impedance of the circuit we use, so we can't actually calcite on the crossover frequency that a specific capacitor value removes.

It's not like a capacitor in a power supply where bigger is better, it's a precise value making a crossover frequency that either makes a highpass or lowpass depending on how it's connected, and if the noise that this jailbar creates is on the same as the wanted signals frequency (RGB/Composite) it will never be solved, it might even mix internally of the HUC6260, and there's no fixing that...

But it's very different from model to model and between individual consoles that's for sure.

[thesteve]

ok a few points
it is like on a supply and it does somewhat mix in the 6260
where it differs from an old supply is the old supply had 120Hz on the line that needed to be filtered
in this case we are dealing with much higher frequencies and sensitivities to adjacent trace currents
the value of the cap is the cutoff freq of the filtering, not a band pass so bigger is better
ESR will be more important then value as will current path (on the NES mini moving 1 trace to a jumper nearly cures it simply by changing the current path

[incrediblehark]

Got my adaptaplug tip in the mail today and doesn't appear to solve my particular issue. Going to start a new thread to not mislead others as it seems unrelated to the jailbar fix.

[Ergot_Cholera]

I finally tried this jailbar fix (with 1206 and then 0805 caps) and noticed no difference on the 2 PCE (original) that I tried, and on a Core Grafx it made them worse! I don't have a Duo to try it with.
I thought this might be a good solution to the problem but I feel disappointed now. How have others fared with their "repairs"?

[MNKyDeth]

I really have not been a part of the conversation on this and I may not understand it all.

But what about the 7805's themselves? I going through all the 7805's on mouser's website each one's datasheet varies on the output noise voltage. I have no idea if this plays a role with something like this.

But I also notice that not every PC Engine Duo or PC Engine Duo-R has the same 7805's as the another.

Could some of the issue be just that the people that experience this effect have a noisier 7805? Even though it works and is good it might just be making to much noise in the system electrically?

I am just throwing it out there as I really don't know how this effects the system but thought it might contribute where other fixes have failed.

[incrediblehark]

I noticed some light jailbars on my white pc engine so I did the repair last night. It was a lot easier for me to swap out the caps on the PC Engine compared to the Duo, and the picture on the PCE is perfect now

[leonk]

I finally tried this jailbar fix (with 1206 and then 0805 caps) and noticed no difference on the 2 PCE (original) that I tried, and on a Core Grafx it made them worse! I don't have a Duo to try it with.
I thought this might be a good solution to the problem but I feel disappointed now. How have others fared with their "repairs"?

Sounds like you did something wrong. Tim actually owns an original white PCE and what he used to figure this out.

[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).

[deubeul]

I really have not been a part of the conversation on this and I may not understand it all.

But what about the 7805's themselves? I going through all the 7805's on mouser's website each one's datasheet varies on the output noise voltage. I have no idea if this plays a role with something like this.

But I also notice that not every PC Engine Duo or PC Engine Duo-R has the same 7805's as the another.

Could some of the issue be just that the people that experience this effect have a noisier 7805? Even though it works and is good it might just be making to much noise in the system electrically?

I am just throwing it out there as I really don't know how this effects the system but thought it might contribute where other fixes have failed.

Hey, I think you make a good point here. I'm curious about TheSteve and other tech guys' thought about it.

[thesteve]

as far as the 7805 noise, that is what the big caps are there for (that and input power)

[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).