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emerson

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About emerson

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    Chopper Commander

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    Male
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    Northeast Ohio
  • Interests
    laserdiscs, old computers, old and somewhat new video games

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  1. Looking at the datasheets for the 7404 and 1n4446 I see that the maximum logic low voltage of the 7404 is 0.8 volts but the forward voltage of the 1n4446 is 1.0 volts. I don't know how diodes act while in parallel but pressing two or more buttons on the same joystick would effectvely put them in parallel. The forward voltage of the 1n4446 would make it so the ground reference inside the joystick is 1.0 volts and not console ground. http://www.ti.com/lit/ds/symlink/sn54ls04-sp.pdf http://www.mouser.com/ds/2/149/1N4446-81810.pdf
  2. Can you test the socketed chips in a known working console? You could try making this simple composite mod to see if the video signal is good. https://chester.me/archives/2019/02/renovating-an-atari-2600-av-mod-capacitors-and-power-adaptor-replacement/
  3. By through hole plating I meant the metal inside the hole that connects the top and bottom traces. Not the actual trace on the surface of the pcb. Typically plating will be attached to the lead of the removed component if it's been pulled out. It's pretty easy to miss if the removed component has a glob of solder on the leads still. Also, a surface trace that has been lifted, even if it still has continuity with itself, will have torn away from the through hole plating and therefore won't be attached to the trace on the other side. This is why it's important to have solder on both sides of a two sided pcb. https://www.pcbunlimited.com/engineering/plated-non-plated-through-holes
  4. Is it possible you inadvertently pulled out the through hole plating while desoldering? The service manual can be found here if you haven't found it already. If you don't have an oscilloscope I recommend using an analog volt meter when measuring high frequency voltages such as the rf signal. The sample rate of a digital meter can affect the reading. A logic probe can be easily built to determine if you have a clock signal.
  5. The schematic I posted earlier has all the component values labeled.
  6. Maybe we can take an educated guess... Looking at the arkanoid paddle info from the nesdev wiki you'll see it uses D3 for the button and D4 for the knob. This page has a schematic of the paddle controller. Here is the nes controller port pinout copied from the nesdev wiki: __ GND -- |O \ CLK <- |O O\ -- +5V LAT <- |O O| <- D3 D0 -> |O O| <- D4 '---' NES port * Directions are relative to the jack on the from of console By looking at the datasheets of a few chips from the schematic, here is my guess of the pinout: BLK - VCC BLU - D4 ORG - CLK RED - LAT WHT - D3 GRN - GND I hope this helps.
  7. I agree. You'll want to open the card and give the contacts a thorough cleaning. Also be sure to clean the contacts on the console as well.
  8. You have to open the console and look at the mod chip wiring. 128KB (kilobytes) is correct. Another way of saying it is 1 Mb or (megabits).
  9. If I remember correctly the controller and memory card use the exact same connections and rely on serial commands to determine which device the console is talking to. If this is true then your controller should not work either if the mod work is bad. See if they pulled power from the memory card port and look for shorts. I assume you've tried cleaning contacts in the console and memory card. Is this an official memory card or third party?
  10. Could you add line drivers or buffers on either side of the extension cable? One on the address lines from console to cartridge, and one on the data line from cartridge to console?
  11. Crystalis, Game Gear and PAL tv tuner sold.
  12. Here is a USB Host controller IC that connects to a microcontroller via SPI. https://www.maximintegrated.com/en/products/interface/controllers-expanders/MAX3421E.html
  13. Lowered prices on most everything. Added some Panasonic AG-1970 vcrs, an N64, a Master System and a Sega CD. Casino Kid 2 sold. Moving computer stuff to VCF forums. Will accept any reasonable offer.
  14. Good, I'm glad everything works now. It's good practice to just leave those "purple jumpers" installed. It's easy to forget those power busses aren't connected in the middle.
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