HunterZero Posted January 22, 2015 Share Posted January 22, 2015 Modulator should be properly adjusted at the factory. You can try adjusting it but it is likely to make things worse. I would look at making sure the power supply is clean first and possibly replace the power capacitors and 12V regulator. This cured a rolling black bar in my Intellivision. Quote Link to comment Share on other sites More sharing options...
juice2839 Posted January 22, 2015 Share Posted January 22, 2015 (edited) Modulator should be properly adjusted at the factory. You can try adjusting it but it is likely to make things worse. I would look at making sure the power supply is clean first and possibly replace the power capacitors and 12V regulator. This cured a rolling black bar in my Intellivision. I have every piece of test equipment you can imagine. I have not used any of it once when I have adjusted the sound choke. You certainly are not going to make it worse unless you try to adjust it with a hammer. I guarantee it's not the power supply in this situation. I have seen this symptom more than a few times. Edited January 22, 2015 by juice2839 Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 23, 2015 Share Posted January 23, 2015 Do you mean adjust the sound buzz level? It could be corrosion in that part, perhaps some contact cleaner in the sound buzz adjuster coil might help? Twiddling the coil might help if there's a bad connection, but it certainly should not need adjustment. Still, checking the power supply is the first thing I do anyway when bulletproofing old electronics. I just don't trust old electrolytics. And in the Intellivision you don't have to crack open the logic board to do it. Sounds like replacing the modulator or doing an AV mod and removing the modulator altogether is the easiest way forward. - J Quote Link to comment Share on other sites More sharing options...
juice2839 Posted January 23, 2015 Share Posted January 23, 2015 (edited) Do you mean adjust the sound buzz level? It could be corrosion in that part, perhaps some contact cleaner in the sound buzz adjuster coil might help? Twiddling the coil might help if there's a bad connection, but it certainly should not need adjustment. Still, checking the power supply is the first thing I do anyway when bulletproofing old electronics. I just don't trust old electrolytics. And in the Intellivision you don't have to crack open the logic board to do it. Sounds like replacing the modulator or doing an AV mod and removing the modulator altogether is the easiest way forward. he RF - J It is a good idea to replace old electrolytics. I am not denying that. Just saying that is not the problem here. The RF modulator certainly could need adjusting. Capacitor values drift over time. Its really not a big deal to use a non ferrous tool and slightly adjust the RF choke and be done with it. At any rate take the advice and experience or not. Edited January 23, 2015 by juice2839 Quote Link to comment Share on other sites More sharing options...
sirtris Posted January 23, 2015 Author Share Posted January 23, 2015 Okay. I wiggled the power switch to death. I don't think that's it. Also I did use the electrical contact cleaner aerosol spray. Sprayed inside both ends of it to get to the contacts. I removed the screws from the controller holder tray and pulled out the entire box that contains the cpu and RF box. It's soldered and sealed from the sides completely enclosed. I noticed something strange about the circuit board near the cartridge port. It appears that the heat shielding metal is making contact with a row of solder points by the cartridge. I realize that this is maybe an intentional ground but it seems strange that so many would be touching the shielding metal. Anyone else seen this before? Quote Link to comment Share on other sites More sharing options...
pimpmaul69 Posted January 23, 2015 Share Posted January 23, 2015 How cheap I might need a couple. He probably only just needs to adjust his. The service manual tells you exactly how to do it and also describes his exact symptom. 4 dollars http://leftturnonly.info Quote Link to comment Share on other sites More sharing options...
pimpmaul69 Posted January 23, 2015 Share Posted January 23, 2015 Okay. I wiggled the power switch to death. I don't think that's it. Also I did use the electrical contact cleaner aerosol spray. Sprayed inside both ends of it to get to the contacts. I removed the screws from the controller holder tray and pulled out the entire box that contains the cpu and RF box. It's soldered and sealed from the sides completely enclosed. I noticed something strange about the circuit board near the cartridge port. It appears that the heat shielding metal is making contact with a row of solder points by the cartridge. I realize that this is maybe an intentional ground but it seems strange that so many would be touching the shielding metal. Anyone else seen this before?that is normal. All those pins are grounded. Quote Link to comment Share on other sites More sharing options...
juice2839 Posted January 23, 2015 Share Posted January 23, 2015 4 dollars http://leftturnonly.info That's a good price. Thanks Quote Link to comment Share on other sites More sharing options...
sirtris Posted January 23, 2015 Author Share Posted January 23, 2015 (edited) I noticed it says Aquarius and Intellivision only for the new modulator. I take it that would work for my Sears unit? And is it worth cracking this thing open to tune or adjust the modulator? If so I guess I'd have to desolder the sides of the shielding. Edited January 23, 2015 by sirtris Quote Link to comment Share on other sites More sharing options...
sirtris Posted January 23, 2015 Author Share Posted January 23, 2015 I tried to to tune the modulator. Definitely found the sound adjust screw. No luck. I went ahead and ordered a new one from the site. Maybe getting a little out of my league here. Is it hard to replace it? Quote Link to comment Share on other sites More sharing options...
juice2839 Posted January 23, 2015 Share Posted January 23, 2015 What did the sound adjust choke do? No help at all? Or mildly help? Quote Link to comment Share on other sites More sharing options...
pimpmaul69 Posted January 23, 2015 Share Posted January 23, 2015 I tried to to tune the modulator. Definitely found the sound adjust screw. No luck. I went ahead and ordered a new one from the site. Maybe getting a little out of my league here. Is it hard to replace it?minimal soldering skills. It isnt that hard to do. Make sure you remove the solder with a solder sucker or solder wick before shoving the new one on. Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 23, 2015 Share Posted January 23, 2015 (edited) You should be able to tap into the analogue audio going into the RF modulator unit, and hook it up to a standard RCA audio input on your TV through a 100uF 25V capacitor, as per the audio mod part of the Solarfox AV mod. You can then check if the audio going into the modulator is clean. http://solarfox.triluminary.net/hwh_intvav_p4.php - James Edited January 23, 2015 by HunterZero Quote Link to comment Share on other sites More sharing options...
intvnut Posted January 23, 2015 Share Posted January 23, 2015 (edited) I noticed it says Aquarius and Intellivision only for the new modulator. I take it that would work for my Sears unit? And is it worth cracking this thing open to tune or adjust the modulator? If so I guess I'd have to desolder the sides of the shielding. It's the same RF modulator in the Sears SVA. The Sears unit actually has the same logic board, IIRC. And I shipped your RF mod out today. BTW, I'm no expert in the soldering department. I find desoldering braid the easiest for me to work with when opening up the logic board. I was able to swap out an RF modulator in maybe 30 - 45 minutes. Went through a bunch of desoldering braid, though. My only other recommendation is to take a photo of the controller cables while they're still connected so you get the orientation right when you plug everything back together. For as much as I remember, I can never remember what direction those connectors go. Edited January 23, 2015 by intvnut Quote Link to comment Share on other sites More sharing options...
freewheel Posted January 23, 2015 Share Posted January 23, 2015 My only other recommendation is to take a photo of the controller cables while they're still connected so you get the orientation right when you plug everything back together. For as much as I remember, I can never remember what direction those connectors go. Take a Sharpie and make a mark indicating "up" on the plastic plug. This way you can never go wrong Quote Link to comment Share on other sites More sharing options...
sirtris Posted January 23, 2015 Author Share Posted January 23, 2015 What did the sound adjust choke do? No help at all? Or mildly help? Quote Link to comment Share on other sites More sharing options...
sirtris Posted January 23, 2015 Author Share Posted January 23, 2015 Didn't help at all. Simply went from a soft crackling almost sounds like percussion version of in game music to a constant hiss sounds of older TVs in between channels. Quote Link to comment Share on other sites More sharing options...
sirtris Posted January 24, 2015 Author Share Posted January 24, 2015 It's the same RF modulator in the Sears SVA. The Sears unit actually has the same logic board, IIRC. And I shipped your RF mod out today. BTW, I'm no expert in the soldering department. I find desoldering braid the easiest for me to work with when opening up the logic board. I was able to swap out an RF modulator in maybe 30 - 45 minutes. Went through a bunch of desoldering braid, though. My only other recommendation is to take a photo of the controller cables while they're still connected so you get the orientation right when you plug everything back together. For as much as I remember, I can never remember what direction those connectors go. Quote Link to comment Share on other sites More sharing options...
sirtris Posted January 24, 2015 Author Share Posted January 24, 2015 Thank you! I guess I'll either do the audio/video mod or replace the modulator completely. Don't have a lot of confidence in my soldering skills but I have a few friends that could probably help if I get in trouble. I really appreciate everyones help and advice. I'm a little frustrated with my purchase but maybe It'll get going eventually. Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 25, 2015 Share Posted January 25, 2015 Soldering isn't too difficult when you get the hang of it. Just remember to heat the joint, then add solder. Desoldering braid, desoldering pump/pullit and flux pen are very useful. Plenty of videos on youtube showing how it is done. Quote Link to comment Share on other sites More sharing options...
guy767 Posted May 30, 2015 Share Posted May 30, 2015 I'm having the exact same issue. In fact, I posted a Youtube video that demonstrates the problem... Here's what I've done without success to fix the issue... 1 - Cleaned the power switch. I took it apart, polished the back of the switch and the three little metal thingies with Brasso and rinsed them with 91% Isopropyl Alcohol. 2 - Adjusted the RF Modulator. I fiddled with both audio and video adjustment points. 3 - Tried unplugging the controllers. I heard that the sound is somehow tied with the controller chip so I tried turning the system on with no controllers, 1 controller, 2 controllers ECT. 4 - Checked for leaking/damaged capacitors and loose/disconnected cables. Everything looked good to my eye at least. I guess the RF modulator is bad on the console but why would the picture be good and not the sound? Also, notice in the video that Thunder Castle's title screen is not the right color? Perhaps this is a ram or sound chip issue? The sound is clear but distorted and without static/ RF interference when no music/sound is played. This leads me to believe that getting a new RF Modulator or installing an AV mod won't fix the sound as one of the chips or ram is bad. Any advice I can get would be appreciated. I especially want to know if the console is worth fixing and if it would be an easy/cheap or difficult/expensive repair. Quote Link to comment Share on other sites More sharing options...
mylok Posted May 30, 2015 Share Posted May 30, 2015 with a sears intv I have found it is the sound chip (8914) that that goes bad quite often. Quote Link to comment Share on other sites More sharing options...
guy767 Posted May 31, 2015 Share Posted May 31, 2015 (edited) with a sears intv I have found it is the sound chip (8914) that that goes bad quite often. Yeah, I strongly suspect that either the ram or the sound chip is the culprit as the RF signal for video is excellent and the sound is clear but distorted. You seem experienced with Sears INTV repairs; can you tell me what I need to purchase to replace the sound chip? Are they expensive? Is ram easily attainable and what's the cost? Could you recommend a guide for ram and sound chip replacement? Sorry for the newb questions but that's what I am and any help would be appreciated; thanks. Edited May 31, 2015 by guy767 Quote Link to comment Share on other sites More sharing options...
guy767 Posted May 31, 2015 Share Posted May 31, 2015 BTW, I'm no expert in the soldering department. I find desoldering braid the easiest for me to work with when opening up the logic board. I was able to swap out an RF modulator in maybe 30 - 45 minutes. Went through a bunch of desoldering braid, though. I haven’t tried removing the RF modulator yet but I was able to de-solder the metal case that surrounds the motherboard pretty easily by adding more solder to the soldered tabs of the metal shielding. I then pried the tabs apart with a small precision screwdriver while still heating the soldered joint. I did this just to access the RF modulators' fine-tuning points only to discover that the metal shielding has 2 small holes on the back to accommodate adjustments without removing it. I'm not a smart man Quote Link to comment Share on other sites More sharing options...
mylok Posted June 2, 2015 Share Posted June 2, 2015 You need to check if the sound chip is soldered to the board or does it use a socket. I have a few extra chips both audio and ram but if it is soldered you would have to de-solder 40 pins not a fun thing to do. Just message me if you want the chips. I am sure we can work something out. Quote Link to comment Share on other sites More sharing options...
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