Myisland Posted February 1, 2016 Share Posted February 1, 2016 Upon discovering your forum I unboxed my Atari 800 after 20 years. I connected it to the 13" CRT TV's antenna plug using the Atari's built-in RF cable and a Computer/TV switch box CA010112 The video looks fine but there is no sound. Quote Link to comment Share on other sites More sharing options...
Myisland Posted February 2, 2016 Author Share Posted February 2, 2016 Does anyone have an idea about getting the sound to work? I've also tested it on a second TV with the same result. Maybe the sound chip died while waiting on me? I bought this in 1982 for $800 and used it in college to program BASIC. I'd feel bad about trashing it after all of these years. Also have an 810, 850, and an IndusGT I found my 520ST is in another box too. Long ago I gave my 800XL,130XE and a 2600 to my nephews. Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted February 2, 2016 Share Posted February 2, 2016 Make sure the fine tuning is set correctly. If that doesn't help, it could be a bad RF modulator. If you have a video monitor (or a TV with the proper input jacks) and a video cable, try that. Does it work with a disk drive? The sound chip (PoKey) also handles disk I/O. Even if the chip is bad, replacements are readily available. A little troubleshooting should be able to solve this problem. Good luck. 1 Quote Link to comment Share on other sites More sharing options...
+Stephen Posted February 2, 2016 Share Posted February 2, 2016 How is "the sound" not working? Do you get key clicks from the internal speaker when typing? Could be the chips just need re-seating. Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted February 2, 2016 Share Posted February 2, 2016 The key clicks and the Ctrl-2 buzzer are produced by the GTIA chip and are routed to the internal speaker on the 400 / 800 and have nothing to do with the sound from PoKey. Quote Link to comment Share on other sites More sharing options...
russg Posted February 2, 2016 Share Posted February 2, 2016 (edited) Upon discovering your forum I unboxed my Atari 800 after 20 years. I connected it to the 13" CRT TV's antenna plug using the Atari's built-in RF cable and a Computer/TV switch box CA010112 The video looks fine but there is no sound. Is the channel switch and TV channel equal? I think you may get a picture even with channel not set right. You could try the other channel even if you tried correctly on one channel. Edited February 2, 2016 by russg Quote Link to comment Share on other sites More sharing options...
+Stephen Posted February 2, 2016 Share Posted February 2, 2016 The key clicks and the Ctrl-2 buzzer are produced by the GTIA chip and are routed to the internal speaker on the 400 / 800 and have nothing to do with the sound from PoKey. Yeah, I know. I was just wondering if the machine was making any noises. I was glad when I got an XE, and could just turn the TV speaker down to eliminate the keyclick. Very annoying feature IMHO. Quote Link to comment Share on other sites More sharing options...
Thorsten Günther Posted February 3, 2016 Share Posted February 3, 2016 (edited) Upon discovering your forum I unboxed my Atari 800 after 20 years. I connected it to the 13" CRT TV's antenna plug using the Atari's built-in RF cable and a Computer/TV switch box CA010112 The video looks fine but there is no sound. Depending on where you live, there could be another reason for this problem: many modern TV sets are hardly used for RF anymore and thus are still set to the factory setting for that connection, and PAL I (labelled "UK") and B/G ("PAL") machines have different sound frequency offsets - so if you have a UK 800 and your TV set is still set to PAL B/G or vice versa, you can not hear the sound via RF. I experienced this issue in 1990 when we were sailing off the Welsh coast with our mine sweepers and could not get sound for the free-to-air World Cup broadcasts by the BBC on our CRT TV - we then muted it and turned on the radio instead. Edited February 3, 2016 by Thorsten Günther Quote Link to comment Share on other sites More sharing options...
Myisland Posted February 3, 2016 Author Share Posted February 3, 2016 Depending on where you live, there could be another reason for this problem: many modern TV sets are hardly used for RF anymore and thus are still set to the factory setting for that connection, and PAL I (labelled "UK") and B/G ("PAL") machines have different sound frequency offsets - so if you have a UK 800 and your TV set is still set to PAL B/G or vice versa, you can not hear the sound via RF. I experienced this issue in 1990 when we were sailing off the Welsh coast with our mine sweepers and could not get sound for the free-to-air World Cup broadcasts by the BBC on our CRT TV - we then muted it and turned on the radio instead. I'm in Los Angeles. Tested using 13" Magnavox CRTMWC13D5 and also a Sony 32" XBR KV32FV26 year 2000 Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted February 3, 2016 Share Posted February 3, 2016 I'm in Los Angeles. Tested using 13" Magnavox CRTMWC13D5 and also a Sony 32" XBR KV32FV26 year 2000 TV's from that era shouldn't have a problem tuning a decent RF signal. Question: do you have access to a video cable for the 800? It would help narrow down the issues if you could see if the audio signal is coming out of the monitor jack. Quote Link to comment Share on other sites More sharing options...
Myisland Posted February 3, 2016 Author Share Posted February 3, 2016 Make sure the fine tuning is set correctly. If that doesn't help, it could be a bad RF modulator. If you have a video monitor (or a TV with the proper input jacks) and a video cable, try that. Does it work with a disk drive? The sound chip (PoKey) also handles disk I/O. Even if the chip is bad, replacements are readily available. A little troubleshooting should be able to solve this problem. Good luck. Not sure what you mean by "fine tuning". Picture is clear but zero sound. I hooked up the 810 disk drive, ran a head cleaner disk, then ran a game floppy and it loaded and ran fine but no sound. Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted February 3, 2016 Share Posted February 3, 2016 Some of the old tv's have a ring around the channel selector that you turn one way or the other to fine tune the reception. It moves the tuner slightly up or down in frequency. Newer tv's don't have this. Quote Link to comment Share on other sites More sharing options...
+Stephen Posted February 3, 2016 Share Posted February 3, 2016 Isn't there an LM386 or such used in the output path? I don't think PoKey can work enough to load a file from disk, but not be able to generate sound. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted February 3, 2016 Share Posted February 3, 2016 Isn't there an LM386 or such used in the output path? I don't think PoKey can work enough to load a file from disk, but not be able to generate sound. POKEY failures can be tricky. I have a 1200XL that would work fine for sound generation and keyboard input but failed loading anything whatsoever through the SIO port. Swapped it with one from a 600XL donor and everything worked fine again. Sent from my iPhone using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
Myisland Posted February 3, 2016 Author Share Posted February 3, 2016 Some of the old tv's have a ring around the channel selector that you turn one way or the other to fine tune the reception. It moves the tuner slightly up or down in frequency. Newer tv's don't have this. I vaguely remember now having a Sony 15" color TV which had one of those back in the 1970's. Quote Link to comment Share on other sites More sharing options...
Myisland Posted February 3, 2016 Author Share Posted February 3, 2016 So far comments indicate a bad RF modulator or bad a POKEY. How do I test which it is? I'm an electronics novice or but can follow instructions. I do repair my own cars, house, appliances, and have built PCs since early days. Today I'm snaking out the kitchen drain pipe. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted February 3, 2016 Share Posted February 3, 2016 Did you see my first post in the thread? If you don't have a spare POKEY handy, buy or make a composite monitor cable and test the audio out. That will let you determine if it's an RF modulator issue or a possible POKEY problem. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Myisland Posted February 4, 2016 Author Share Posted February 4, 2016 Did you see my first post in the thread? If you don't have a spare POKEY handy, buy or make a composite monitor cable and test the audio out. That will let you determine if it's an RF modulator issue or a possible POKEY problem. Sent from my iPhone using Tapatalk I should still have a homemade composite cable from when I owned an Amdek monitor. I'll have to find the pin-outs chart. Quote Link to comment Share on other sites More sharing options...
Myisland Posted February 15, 2016 Author Share Posted February 15, 2016 Atari 800 Update: I found my old homemade monitor cable and connected it to TV using the RCA video and audio connectors. I got clear sound but no video. I'll need to find the pin-outs chart somewhere. Quote Link to comment Share on other sites More sharing options...
Myisland Posted July 3, 2016 Author Share Posted July 3, 2016 Atari 800 Update: I found my old homemade monitor cable and connected it to TV using the RCA video and audio connectors. I got clear sound but no video. I'll need to find the pin-outs chart somewhere. By chance I acquired an Amdek Color-I monitor and connected it to the Atari 800 using my old homemade cable. Both video and sound works but there is too much hum. How do I fix the hum? Quote Link to comment Share on other sites More sharing options...
jham55 Posted May 17, 2022 Share Posted May 17, 2022 I'm in the same boat only no sound or video. Quote Link to comment Share on other sites More sharing options...
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