7800 Posted June 25, 2014 Share Posted June 25, 2014 I recently purchased a 520 ST and HxC floppy emulator. When I first hooked it up and loaded a game I got sound... so I know the speaker on the monitor works. Now, I can load any game and I get NO SOUND from any of them. Did I accidentally toggle off the sound either on the HxC floppy emulator or the computer itself??? Quote Link to comment Share on other sites More sharing options...
RodLightning Posted June 26, 2014 Share Posted June 26, 2014 (edited) I haven't opened a STFM in years, but if I remember correctly, the Yamaha sound chip is located near the floppy drive bay. I would check to see that nothing is shorted from the floppy emulator hardware you installed. Do you at least hear keypress sounds? Edited June 26, 2014 by RodLightning 1 Quote Link to comment Share on other sites More sharing options...
7800 Posted June 26, 2014 Author Share Posted June 26, 2014 It just occurred to me after starting this thread that the STfm has the RCA out for use with a TV. So I hooked it up to a TV and sure as shit, I get sound. What baffles me is that I was initially getting sound from the monitor speaker intermittently, then nothing at all. I'm wondering if the monitor speaker is flaky. I will need to investigate... but not tonight. Quote Link to comment Share on other sites More sharing options...
Rybags Posted June 26, 2014 Share Posted June 26, 2014 Check the monitor plug, 13 pins in a small area so pretty delicate. 1 Quote Link to comment Share on other sites More sharing options...
RodLightning Posted June 26, 2014 Share Posted June 26, 2014 It just occurred to me after starting this thread that the STfm has the RCA out for use with a TV. So I hooked it up to a TV and sure as shit, I get sound. What baffles me is that I was initially getting sound from the monitor speaker intermittently, then nothing at all. I'm wondering if the monitor speaker is flaky. I will need to investigate... but not tonight. I would check with the volume knob/pot. Then there's the audio out pin on the monitor jack (pin 1). Cleaning both would be a good start. You can actually test pin 1 for sound by making a line out patch cable (pin 13 is ground). It's just analog mono audio. You would have to stick two wires into the appropriate holes. Daring, but effective. I used to connect a Amdek composite monitor to my 520stfm that way with four wires before finally getting the proper cable. Quote Link to comment Share on other sites More sharing options...
7800 Posted June 26, 2014 Author Share Posted June 26, 2014 I will do that. Would you happen to have a diagram of the pin holes showing the numbers? Quote Link to comment Share on other sites More sharing options...
ParanoidLittleMan Posted June 26, 2014 Share Posted June 26, 2014 First check AV cable and connectors. Usually it just needs resoldering of wire Quote Link to comment Share on other sites More sharing options...
7800 Posted June 26, 2014 Author Share Posted June 26, 2014 (edited) So, I spent a few hours trying to figure out what the sound problem is with the monitor. I have come to the conclusion that there is a bad trace in the harness. If I bend the wire just right, the speaker works. Oh well, at least I figured out what the deal is... now I just need to see if I can find a new harness... maybe best has them. Also, the monitor harness is hardwired so... replacing it might not be possible unless it's from a junked unit. It's a SC1224 Hitachi tube version. Edited June 26, 2014 by 7800 Quote Link to comment Share on other sites More sharing options...
Android8675 Posted June 26, 2014 Share Posted June 26, 2014 Think it's pretty easy to replace the harness, just gotta get a replacement. Watchout around CRT tubes, they hold enough voltage to kill ya. Quote Link to comment Share on other sites More sharing options...
7800 Posted June 26, 2014 Author Share Posted June 26, 2014 The harness is hardwired to the inside of the monitor. It can be replaced but... are they really out there? Any idea where I can start looking? Quote Link to comment Share on other sites More sharing options...
RodLightning Posted June 26, 2014 Share Posted June 26, 2014 If you haven't seen it already, this recent thread about st monitor cables may help with your endeavors. http://atariage.com/forums/topic/225993-13-pin-din-adapter/ Otherwise, I agree that Best Electronics is the most likely place to look for a oem sc1224 wiring harness. Btw, I think there were two or three differet versions of the sc1224. Quote Link to comment Share on other sites More sharing options...
7800 Posted June 26, 2014 Author Share Posted June 26, 2014 Thanks. For now I think I'm going to use the RF modulator port just for audio if I can... since I am getting awesome video on the Atari monitor. Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.