Author Topic: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W  (Read 5542 times)

incrediblehark

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #30 on: January 19, 2016, 10:14:33 AM »
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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #31 on: January 19, 2016, 10:23:48 AM »
The original is an el cheapo unregulated model, yeah, I would upgrade it quick. Might as well give less work to the internal regulators.

http://www.pcenginefx.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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #32 on: January 19, 2016, 10:45:09 AM »
The original is an el cheapo unregulated model, yeah, I would upgrade it quick. Might as well give less work to the internal regulators.

http://www.pcenginefx.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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #33 on: January 19, 2016, 03:48:54 PM »
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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #34 on: January 20, 2016, 02:23:39 AM »
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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #35 on: January 24, 2016, 07:02:50 AM »
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.
GW/GB/GBP/GBL/GBC/GBA/GBASP/GBASP2/GBM/DS/DSL/DSiXL/3DS/PM/VB/FC/NES/SNES/N64/GC/Wii/PS/PSONE/PS2/PS2S/
SMS/SMS2/GG/NOM/MD/MD2/MD3/MD1CD/SS/DC/XB/XB360/NGP/NGPC/NGPC2/WS/WSC/CSW/PCEGT/PCE/PCECG1/PCECG2/
PCECD/TG16TE/NGAGE/GIZ/GP32/GP2XF1/GP2XF2/GP2XWIZ/GP2XCAN/DA320/ST520/ST1040/LNX/LNX2/JAG/PORT/CD32/A500/
C64/CDi/VMU/POCKSTN/PSP/PSPCFW/FDS/VSM

thesteve

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #36 on: January 24, 2016, 11:03:20 AM »
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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #37 on: January 25, 2016, 01:55:31 PM »
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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #38 on: January 30, 2016, 04:55:37 AM »
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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #39 on: January 30, 2016, 05:14:59 AM »
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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #40 on: January 30, 2016, 07:31:13 AM »
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 :mrgreen:

leonk

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #41 on: January 30, 2016, 07:41:06 AM »
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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #42 on: January 31, 2016, 05:50:50 AM »
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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #43 on: January 31, 2016, 06:28:31 AM »
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

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Re: PC Engine 'Jail Bar' Video Noise - repair guide by Tim W
« Reply #44 on: January 31, 2016, 02:22:49 PM »
as far as the 7805 noise, that is what the big caps are there for (that and input power)