dafa_123

Hello, I have a Sega Saturn that will not power up. I cannot find any schematic for the Yamaha XS205 Rev C power supply. I believe that the transformer is bad. I get continuity on the high voltage side but not on the low voltage side. On the high voltage side, I get ±160v DC but nothing on the low voltage. I am unable to find the part number of the transformer. The transformer is green and the number on top shows: XR909 A T64. Anyone know a replacement part number for that transformer? Thanks.

Indeed. I don't mind trying. I only need a schematic to built a 15kHz signal generator that can replicate the one on the SNES. I have a working SNES to compare the signal to. You don't have such a schematic by any chance?

As I suspected, on the defective SNES, I get no signal on pin 100 of PPU2 U3. When I compare to a working SNES (See picture), which gets a 15kHz signal on pin 100. Does anyone know if it would be possible to create a replacement 15kHz RSYNC using an external circuit? Would it work? Thnaks.

If I check with an oscilloscope, what kind of signal should I be getting out of pin 100? If I had a reference, I could compare.

Do you know if pin 100 of U3 is the one doing the video sync?

I checked all the lines for the PPUs and RAM and everything looks fine. I also checked the grounds and VCC and they also llook fine. When I look at the electric diagram, I see pin 100 of PPU2 U3 that says CSYNC that goes to both the RF Module and the AV out connector. Does anyone know if that is what is used to sync the image on the TV? If U3 is not sending the correct signal out of pin 100, could that be the issue? Thanks.

I have the same issue with RF.

Do you know a good RGB Mod for the SNES?

I have tested with a different PSU and cables. I have another SNES that works fine with the all my cables and both PSU that I have. Since I have the same issue with RF and RCA, the issues seems to be elsewhere.

Power looks good according to the meter. Which of the chips could be causing the issue? Does not look like a RAM or PPU issue from what I saw on Youtube, but I could be wrong. Since all the tests pass on the diagnostic, I am not sure what what to look at next! It seems like there is something wrong with the video output.

First one. US model.

Here is a video of Starfox on another TV and the diagnostic cartridge test. What I would like to know is if there is a repair manual for the SNES like they have for the Intellivision and Colcecovision that can tell you what to check, and what kind on signal to expect from a meter or oscilloscope. VID_20200222_125644.mp4

It depends on the board version that you have. On mine, it's under the metal shield next to VA1 and between the voltage regulator and a very large capacitor.

Model on the board says SHVC-CPU-01. USA, I think.

Yes, I have a Starfox cartridge, exact same issue.

Yes, I tried on 2 different CRT.

Not sure were to post this. I have a SNES with the image continually flickering. The keeps going up, down, up, down like when we had an old TV with rabbit ears that was not properly adjusted. (See video) I have already checked the power, AV cables, replaced all the capacitors, try to adjust the little screw near the oscillator crystal, replaced the oscillator crystal and I keep getting the same issue with RF, composite and component cables. When I manage to run the test cartridge, all systems pass the test. I get no Fails. Any ideas what to look at next? VID_20200406_163351.mp4

I had a SNES with a black screen and no sound. D1 was dead. Replaced it and the image and sounds came back. If you have a meter, you can check if you have power past D1.

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

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.

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

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?

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.

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.

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