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dafa_123

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About dafa_123

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  1. Hello, I know that I am in the Genesis section, but can't seem to find a SNES section. I have a SNES that had no video but the sound was working. After looking at the schematics and doing some diagnostic, I found out that D1 was dead. I've replaced the diode and now I get the image but it's continuously flickering (See attached video). I've managed to run a burn-in test and everything passes. I am thinking that I may have a bad capacitor somewhere. I am looking at ordering a replacement kit but I would love to have a second opinion on this issue. Thank you. VID_20200222_125644.mp4
  2. Does any one know how many overlays came with Dr. Seuss and Cabbage Patch Kids Picture Show? I recently got a Dr Seuss and CPKPS that seemed new in box, but they only got 1 overlay. Was wondering if that's normal? Thanks.
  3. I used pin 2 of the RF box with a 10uF capacitor and it works great. Image and sound are crystal clear. Completed reassembly and cleaned the two very dirty controller that came with the console and voilà! Just like new, well... almost Once again, thanks for helping revive this dead console and saving it from the scrap yard. VID_20200118_165322[1].mp4
  4. Replaced C2 with the 85nF and it works. Super clear and sharp image. For the Audio, should I connect the RCA directly to pin 2 of the RF box or should I put a capacitor or some other component between pin 2 and the RCA connector?
  5. Purchased the parts and build it myself. C3 - pin is facing the 75 ohm resistor and the + side is on pin 6. For C2, I have some ceramic 85nF on hand, would that work or should I go back to the store and get 0.1uF? The IC I got from the store is a LM318P I checked the schematic, and everything appears Ok.
  6. I may need your guidance once more. I followed the schematic but replaced C3 with a 470uF as you mentioned and put a 10uF at C2. Unfortunately, the store did not have any ceramic 10uF so I got the electrolytic one for now. I don't get an image when connecting to the TV. I took some oscilloscope reading on the input at pin 6 of the RF box and the RCA output. The input signal seems different when the AV Mod is connected. I don't know if it's normal.
  7. I will try it. I will get the missing components tomorrow and try to built it this week end. I'll keep you posted on my progress. Thanks. Daniel
  8. IT'S ALIVE!!! Yeah The GPU I got from Ebay was a TMS9929. I installed the old TMS9928 and got the image with the proper speed. I got some thermal glue and I am going to put the heat sink back on tonight. Thank you for your time and patience on this project with me If you ever finish that diagnostic kit, let me know. I would be happy to buy one. Next step, AV MOD. I got a schematic that seems straight forward. Any thoughts on this mod? Coleco AV MOD.docx
  9. Eureuka, got an image and sound. The image is constantly flickering. I am thinking that I could adjust it with the little screws in the RF module. The weird thing is that the sound and game play are a little slower than they should. Any idea why? Check my video VID_20200115_205714[1].mp4
  10. resistance between pin 14 and the +5V at the plug = Don't get any reading. between pin 7 and the ground at the plug = 0.35 ohm I found something strange when I was testing the pins on U8. Pins 3, 8 , 9 and 12 are connected together. Is that suppose to be like this? From the datasheet, I understand that 8 and 12 are supposed to be connected but I don't think that 9 should be there??
  11. There is something wrong with U8. I got some Deoxit and used it. I also got a brand new 74LS74, I get a similar clock on Pin 11 but my Vmax is a lot lower than yours. The signal that I get on pin 3, 8, 9 are unstable. I get a Vmax of 1.88v on Pin 3. I get a Vmax of 1.88v on pin 8. I get a Vmax of 2.8v on Pin 9. I get a Vmax of 1.66v on pin 6 of U1. The frequencies are all completely erratic on those pins. No stable signal!? Here is my clock on Pin 11
  12. I put the probe x10 and put the 10x in the Ch1 Probe in the software. I added Vmin and Vmax and Frequency on screen. When I measure U8:11 I get Vmin -1.37v, Vmax 3v and Vpp of 4.38v and the frequency goes rapidly from *** to 7.14Mhz and sometime I see quickly 3.58Mhz and it oscillate rapidly between the 3 measurements.
  13. This what I get when I measure directly on each pins of that silver 7Mhz "crystal". Not sure if it's supposed to be like that.
  14. I checked the traces and they are all good. I took some new measurement of U8 using the original 74LS74 and 2 other 74LS74 that I got before Christmas and I get the same results. I checked with the calibration hooks on the oscilloscope to make sure that it was working properly and it is. Cam the 7Mhz, I thinks it's a crystal, on the board be bad? Here the readings that I am now getting!
  15. Found the Vpp. Thanks. I put the old 74LS74 and still getting a flat line. It's possible that I damaged one of the traces when I removed the old IC. Do you have by any chance the schematic showing where each pin of U8 goes? I see some of the pins on the schematics you sent me for U8 but not all of them. Otherwise, I will try and figure it out by following the traces if possible.
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