AV Famicom+NESRGB+Everdrive=speckles/lines issue.

[Shnryuu]

This is a painfully random issue I'm facing together with AV Famicom, Tim Worthington's NESRGB and Everdrive N8 installed. I've been looking for information across the internet and I noticed that some people have removed their 2SA937 Q1 transistor alone or with resistor that sits next to it to solve this. I've done both and I haven't had any good luck with this. This issue is propably happening like a combo; so Everdrive + NESRGB and a specific console model might trigger this issue. Issue is that I see some random speckles and lines on black areas and that makes me to wonder is there something interfering something. I've also seen some information regarding about pulling out an leg from the PPU. If I remember correctly that leg is numbered as 21. I'm not an expert at electronics but I've tried to find possible soldering issues out. This isn't really AV Famicom alone related so I don't really know is this is the best place to ask for information though

I live in Europe so we have different standards here. I've taken that into account as well. I have two adapters and I can change voltage values from the other one. I've been using 9V setting. Both have the same specifications like; AC-DC adaptor, 9W, Input: 100-240V~50/60Hz Output: 9V 1A.

Any help I can get is fine and I'm willing to dig more information from my console if needed. I've been struggling with this for a while and I don't know what persons I really should contact about this. I know that even gametech.us solved this by removing a transistor but that didn't help

Console information:
SN: HN10772197
CPU: HVCN-CPU-01

[Pikkon]

Does this happen on a crt or hd tv,also if you use a regular game does the issue occur.

[Shnryuu]

I haven't tried with a real cart yet because I need an adapter. Happens on both HDTV and CRT as well. I've only seen people having this issue on NESRGB + Everdrive N8 setups. Many people claim it to be related to PPU. My PPU revision is H which should fix this issue but it doesn't seem to. I'm also interested to know how I can debug this further on.

[Frank_fjs]

I know a recent batch of RGB boards had a faulty transistor, this could be your issue.

Everdrives also pull more voltage than they should which may be contributing to the problem. Best bet is to try with a normal cart and go from there.

Also worth trying a good quality PSU, cheap ones will create interference.

[Shnryuu]

That's interesting! This is the information for the board, NESRGB14 T. W. 2015. I'll try to look for more inforamtion about those transistors as well . I've tried couple of different PSUs. One of them is Eagle's switching power supply in its model is P00C. PRI:100v-240V~60Hz/50Hz 0.25A. SEC: 3/4.5/5/6/7.5/9/12V 1A 12VA. I'm using 9V setting and a correct pin at the end. Other is from Japanspel's shop with same specs and 9V but without possibility to change voltage. I'll try to get a cheap cartridge or a good adapter so I can test this without everdrive. My PPU top of the board is RP2C02H-0 4AM 4J.

[Frank_fjs]

Official info about the faulty boards:

http://etim.net.au/nesrgb/background_fault/

[Shnryuu]

Official info about the faulty boards:

http://etim.net.au/nesrgb/background_fault/

Seems to be fine. This has a circular mount and a good printing. Model is 1644 320 and I can see a good Microchip logo we well. This seems to be ruled out

[Frank_fjs]

My suspicions based on what I think is most likely to least:

The ED cart

The power supply

The video cable (what type are you using?)

The installation

The fact that Famicoms have a poorly designed motherboard prone to introducing interference to the audio and video lines.

The top two suspicions may be related. The ED carts draw more power than the console is rated for. Coupled with an inadequate power supply and other components (such as video chips) are starved for power. I've seen this exact problem before with a component modded Super Famicom. Solution is to use a higher rated PSU, i.e. more Amps. That or stop using the ED, your console will last longer too.

[Shnryuu]

I've tried couple of different PSUs and there's no difference. Second one outputs 1A, I wonder should I go higher? I'm using a shielded RGB scart cable. I haven't found anything suspicious yet on the installation but I'm trying to find any possible interferance. I'm practicing speedrunning mostly on my Everdrive so I'm not willing to throw it away but thanks for the advice though.

[Frank_fjs]

With the ED you will need a 1.5 to 2 Amp PSU. The Famicom is drawing its power, on top of the ED, on top of the RGB board.

To elaborate on the Super Famicom issue... A friend had a Super Famicom and was using a Retrovision component video cable. This cable draws 5V to power an IC. The combination of the video cable and ED drawing extra power resulted in bad video interference. This only happened with the ED cart inserted, regular game carts worked fine. He was using a 1 Amp PSU. We switched to a 2 Amp PSU and problem fixed.