electromaster_84

Sorry for not replying sooner, and I hope you have resolved the issue by now. To answer your question, since the last time I posted I have removed the capacitor from the audio line of my console with no ill effects. I found it made the audio a bit harsh, and since the mod board just passed the audio straight through I figured it wasn't needed. After tinkering with my console for awhile I've found the best solution to this problem is to route the audio wire away from the video wire of the mod board. In my opinion this problem stems from using the unshielded solid core wire provided in the mod kit causing interference between the audio and video signals. If I were to install this kit again I would use some kind of shielded av cable instead of the wire provided.

First I would like to apologize if this is considered thread necromancy, but I have finally found a solution to this problem! I would like to thank rednakes1 for his suggestion to add a 1uf capacitor to the audio line. Adding the capacitor had zero effect on the problem, but did get me thinking back to my initial testing. When the audio was disconnected from the mod board no vertical lines appeared when a sound should have been played. I couldn't hear if a sound had been played of course because the audio was disconnected. I just wasn't thinking straight or was frustrated with the whole mess back then, so I reconnected everything and lived with it. Until today that is when inspiration struck me! What if the audio circuit of the mod board itself was causing the interference? Could it be so simple as to just bypass the audio around the mod board completely? Well I'm here to tell you it is, and why I didn't think of it sooner boggles the mind. So today I soldered a short length of wire from R206 to the positive terminal of a 1uf capacitor, and soldered another length of wire from the negative terminal of the capacitor to the audio jack. Boom presto I had glorious audio, and no interference or vertical lines marring the picture. TLDR Disconnect the audio from the mod board. Then connect the positive terminal of a 1uf capacitor to R206, and the negative terminal to the audio jack with some wire.

well yeah the op could, but I can't because I don't own a megadrive model 1. Also there are 30+ capacitors on some of those boards. I wouldn't want to have to count and write down all those capacitor values if it wasn't necessary.

You will have to look up which motherboard revision you have and go from there. I found some info, and one site that sell complete capacitor kits for NTSC systems. Links http://console5.com/store/kits/console-cap-kits.html?cat=120 http://console5.com/wiki/Genesis http://www.sega-16.com/forum/showthread.php?10012-Genesis-Capacitor-List

I would check and see if there is a blown fuse somwhere near the power input. You could also check if power is getting to the voltage regulator with your multimeter. Pin 1 is the input voltage, pin 2 in the middle is ground, and pin 3 is the output +5v. Here's a link to the 7805 datasheet https://www.fairchildsemi.com/datasheets/LM/LM7805.pdf Also if you eventually get it working I would recommend replacing the voltage input capacitors.

Anybody got any idea as to what is causing this?

I never owned a Nes, but aren't the cartridges taller and wider than Atari carts? Maybe they just look thinner? Get Well Soon!

I only have Activision, Parker Brothers, and Atari carts. Publisher Length (top to bottom) Width (side to side) Depth (thickness) Activision 97mm 81mm 20mm Parker Bros. 98mm 82mm 20mm Atari 98mm 82mm 20mm It was a little hard to measure the width (side to side) on the Atari and Parker Brothers carts because of the curved edges

First I know the picture quality isn't great, but it's really hard to capture the problem on camera from a crt television. My console is a composite modded 4-switch vader. The mod I used is a simple transistor and 2 resistor type ordered from Vintage Gaming and More (http://www.vintagegamingandmore.com/product/atari-video-mod-kit/) The kit was easy to install, and everything seemed to go well. The video quality isn't the best, but it's good enough for me. Anyway on to the problem I've been having. If you look near the center of the screen in the pictures you will notice some type of small lines or static. The lines/static only appear when a sound is played, and it seems the higher the pitch of the sound the more noticeable it is. I've done some testing and I'll just list my findings along with the parts I've removed from the motherboard below. Parts Removed From Motherboard 1) RF Module 2) Q201 3) R209 4) L201 (Audio Coil/Inductor) Testing Steps Result 1) Removed RCA audio cables from jacks on atari to tv No audio, but lines still appeared 2) Replaced capacitors C214,C201,C241,and C243 No change lines still appeared 3) Desoldered Audio wire from mod board to R206 No audio, but also no lines I haven't tried replacing the two audio capacitors C206 and C207 because I don't have any suitable replacements on hand.

I agree that the harmony cart is probably not at fault here, and would not cause any problems unless the regulator was on it's way out already. Come to think of it are the regulators in those models the kind with a heatsink clipped/bolted to them instead of being bolted to the board? If so I would check the solder points on the regulator and see if one or more have cracked, and make sure the heatsink is securely connected to the regulator.

Just noticed those cables you linked are 50 ohm impedance (https://telcoantennas.com.au/site/guide-antenna-cables-connectors), and I think you may want to use a 75 ohm impedance cable instead. 50 ohm is used for things that transmit and receive signals because of it's power handling characteristics, but for a device that just receives signals like a television 75 ohm works best. Here is a link that might shed some light on the subject for you http://cablesondemandblog.com/wordpress1/2014/03/06/whats-the-difference-between-50-ohm-and-75-ohm-coaxial-cable/

You could use a right angle adapter inside the console, and then you wouldn't have to make such a sharp bend at the rca connector. I'm not sure if your using a straight rca connection or some kind of rca to coaxial adapter/switch box, but there are adapters for both. (RCA to RCA) http://www.monoprice.com/Product?p_id=10586&gclid=CjwKEAjw3fG4BRDsn9GAv7T2zEkSJACNJdjg5N_nIphI6iMSJMITC7oXhsuVmfWVIMG9LmQ8c4txRhoC2W3w_wcB (RCA to F-type Coaxial) http://www.showmecables.com/product/F-Type-Female-Right-Angle-to-RCA-Plug-Adapter.aspx?utm_source=google&utm_medium=cse&utm_campaign=688&gclid=CjwKEAjw3fG4BRDsn9GAv7T2zEkSJACNJdjgqN_us8pp2g1R4bn_WPy5eaGltpvmk7DNQ75oFydhdxoCnP7w_wcB

To be clear the only reasons i suggested using a higher amperage voltage regulator were as follows 1) The original regulator is over 30 years old, and I would replace it anyway if it was suspect. 2) the op is using a harmony cart, and that draws a little more power from the system. Other than that it sounds like you know the Atari 2600 better than me, so I would suggest the op check out that post you linked. I would still suggest replacing all electrolytic capacitors, voltage filtering cap (green chicklet near the regulator), and the voltage regulator itself. There are kits out there that can be had for under $10.00 that come with all the parts I mentioned, and more. http://console5.com/store/atari-2600-total-refresh-kit-new-capacitors.html

The harmony cartridge draws power from the system, so it could be stressing the voltage regulator if its a little weak already. You could try playing a normal cartridge and seeing if the same behavior occurs. The best way to know for sure would be to use a multimeter and measure the voltage from the regulator. Also it could be a bad/cracked solder joint somewhere on the board, and when it heats up it loses connection. If it is a bad solder joint I would think the most likely areas to look for one would be the power jack, power switch, and cartridge slot. All of these areas see stress, and over the years one of the solder joints could have failed. One other thing to check would be the power switch, they can get dirty and have poor contact. The way I always check these is to power up the system, and give the switch a gentle wiggle up/down and side to side. Don't use enough force to throw the switch, but enough for the contacts inside the switch to move a little. If the screen glitches, the system shuts off, or anything out of the ordinary happens the switch is bad. If that's the case you can either desolder and clean the switch, or buy a new one. If it were me I would recap the board (new capacitors), and replace the voltage regulator with a higher amperage equivalent (7805cv 1.5 amp). If the chips (TIA, RIOT, and CPU) are socketed i would pull the chips, and clean them.