Dr.Buddha Posted May 16, 2020 Share Posted May 16, 2020 (edited) I picked up a Jaguar that has the R/P board. Everything seems to work but theres terrible static over the top of any sound thats played. Its not static all the time, just when a sound is played. It does it both on RF and with one of those composite adapters. Reg1 is outputting 5v as normal and the whole board is recapped. I thought it might have been an issue with the cap job but that turned out not to be the case after further investigation. All the caps are the correct rating and seem to have intact traces. I posted a video to the consolerepair subreddit if that helps. Thoughts? Edited May 16, 2020 by Dr.Buddha Quote Link to comment Share on other sites More sharing options...
neo_rg Posted May 16, 2020 Share Posted May 16, 2020 That sound more like over amplification , distortion is much like static. Quote Link to comment Share on other sites More sharing options...
Dr.Buddha Posted May 17, 2020 Author Share Posted May 17, 2020 6 hours ago, neo_rg said: That sound more like over amplification , distortion is much like static. any idea what might be causing that? Quote Link to comment Share on other sites More sharing options...
eightbit Posted May 17, 2020 Share Posted May 17, 2020 Did you try to connect this to another audio source with the same result? A set of amplified speakers or a stereo receiver? Quote Link to comment Share on other sites More sharing options...
Dr.Buddha Posted May 17, 2020 Author Share Posted May 17, 2020 7 hours ago, eightbit said: Did you try to connect this to another audio source with the same result? A set of amplified speakers or a stereo receiver? 2 different tvs and the guy I got it from said it did the same so thats at least 3 different devices Quote Link to comment Share on other sites More sharing options...
Zerosquare Posted May 17, 2020 Share Posted May 17, 2020 Check the audio signal on pin 6 (left channel) and pin 8 (right channel) of U5 (located on the bottom left of the PCB). Is it distorted as well? Quote Link to comment Share on other sites More sharing options...
oakcitycomics Posted May 17, 2020 Share Posted May 17, 2020 Are you using the Atari power supply? I know some of these cheap ones everyone is hocking off on amazon and ebay cause static with a lot of the retro consoles. Very common issue on Genesis and SNES. Just a thought Quote Link to comment Share on other sites More sharing options...
Dr.Buddha Posted May 18, 2020 Author Share Posted May 18, 2020 17 hours ago, oakcitycomics said: Are you using the Atari power supply? I know some of these cheap ones everyone is hocking off on amazon and ebay cause static with a lot of the retro consoles. Very common issue on Genesis and SNES. Just a thought using a genuine power supply that works fine with other systems Quote Link to comment Share on other sites More sharing options...
Dr.Buddha Posted May 18, 2020 Author Share Posted May 18, 2020 17 hours ago, Zerosquare said: Check the audio signal on pin 6 (left channel) and pin 8 (right channel) of U5 (located on the bottom left of the PCB). Is it distorted as well? is it a line level audio signal coming out of those pins? trying to figure out a way to check them without a scope. Quote Link to comment Share on other sites More sharing options...
Dr.Buddha Posted May 18, 2020 Author Share Posted May 18, 2020 (edited) 20 hours ago, Zerosquare said: Check the audio signal on pin 6 (left channel) and pin 8 (right channel) of U5 (located on the bottom left of the PCB). Is it distorted as well? Well I soldered on some wires to pins 6 and 8 and connected them to some powered speakers. Yes, pins 6 and 8 are producing static hiss with game sounds barely audible underneath Would that mean U5 is most likely needing to be replaced or something further back in the line? Edited May 18, 2020 by Dr.Buddha Quote Link to comment Share on other sites More sharing options...
Zerosquare Posted May 19, 2020 Share Posted May 19, 2020 (edited) - Check if the supply voltage on U5 is correct (pin 5 is +5V, pin 4 is ground). - Check the voltage between the common point of R64 and R65 (AVREF) and ground. It should be about 3.3 V. - If you have an oscilloscope : check that the waveforms on pins 1, 2 and 3 are clean. Pins 1 and 2 are square wave clocks, pin 3 is a digital bitstream. If all those checks don't show anything wrong, U5 is likely defective. Edited May 19, 2020 by Zerosquare Quote Link to comment Share on other sites More sharing options...
Dr.Buddha Posted May 19, 2020 Author Share Posted May 19, 2020 4 hours ago, Zerosquare said: - Check if the supply voltage on U5 is correct (pin 5 is +5V, pin 4 is ground). - Check the voltage between the common point of R64 and R65 (AVREF) and ground. It should be about 3.3 V. - If you have an oscilloscope : check that the waveforms on pins 1, 2 and 3 are clean. Pins 1 and 2 are square wave clocks, pin 3 is a digital bitstream. If all those checks don't show anything wrong, U5 is likely defective. 5v supplied to U5 and 3.3v on R64 and 65. sadly I dont have a scope yet so I guess I'll just go ahead and try to replace U5. They seem to be around $5 on ebay so no big loss if it doesnt help. Thanks for your help. I really appreciate it. Quote Link to comment Share on other sites More sharing options...
Dr.Buddha Posted June 8, 2020 Author Share Posted June 8, 2020 well after waiting several weeks for a replacement U5 to arrive, I replaced it... and it still has the same issue... Thoughts? Quote Link to comment Share on other sites More sharing options...
Zerosquare Posted June 9, 2020 Share Posted June 9, 2020 Try desoldering U10, and connecting pin 12 to pin 9. Quote Link to comment Share on other sites More sharing options...
Dr.Buddha Posted June 10, 2020 Author Share Posted June 10, 2020 On 6/9/2020 at 5:19 AM, Zerosquare said: Try desoldering U10, and connecting pin 12 to pin 9. went to desolder U10 wasnt paying attention and desoldered U9 instead cursed a lot went to resolder U9 dropped it off the table into carpet cursed a lot found and resoldered U9 desoldered U10 soldered a jumper from pin 9 to pin 12 where U10 used to be same static audio issue Quote Link to comment Share on other sites More sharing options...
Zerosquare Posted June 10, 2020 Share Posted June 10, 2020 Last try: check continuity: - Pin 58 on U15 ↔ pin 1 on U5 - Pin 59 on U15 ↔ pin 12 on U10 - Pin 60 on U15 ↔ pin 3 on U5 Quote Link to comment Share on other sites More sharing options...
Dr.Buddha Posted June 10, 2020 Author Share Posted June 10, 2020 (edited) 43 minutes ago, Zerosquare said: Last try: check continuity: - Pin 58 on U15 ↔ pin 1 on U5 - Pin 59 on U15 ↔ pin 12 on U10 - Pin 60 on U15 ↔ pin 3 on U5 all have continuity... Itll be heart breaking to junk this system when its so close to working, but unplayable is unplayable. Thanks for your help Edited June 10, 2020 by Dr.Buddha Quote Link to comment Share on other sites More sharing options...
Zerosquare Posted June 10, 2020 Share Posted June 10, 2020 (edited) Sorry, I'm out of ideas... there must be a more serious fault somewhere else, but this is getting too complex for remote diagnostic. Don't throw it in the trash though, at worst it can be useful for spare parts. Edited June 10, 2020 by Zerosquare Quote Link to comment Share on other sites More sharing options...
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