austodd Posted February 20, 2019 Share Posted February 20, 2019 So I have an INTV System III that started displaying garbled graphics. After doing some online research (most of it here on AtariAge) I determined that perhaps the problem was with the RA-3-9600 SRAM chip, so I figured I'd try swapping out this chip with an RA-3-9600 from another one of my working Intellivisions. I swapped the chips without too much trouble, but when I hooked everything back up and turned my System III back on, I got no signal. Just static on the TV. So I figured maybe I did something wrong, so I removed the donor RA-3-9600 and re-inserted the original one. Turned the unit back on and - static. I can see that the unit is getting power because the red power light on the System III is lit. At this point I figured that maybe this just wasn't my night so I reassembled my donor Intellivision, which was previously working just fine, hooked it back up and - nothing. Again, just static on the TV. I thought that perhaps maybe something is wrong with my RF cable, so I took the RF cable and hooked it up to yet another Intellivision, and that one outputs a signal just fine. So it's not a problem with my TV or RF setup, and I verified that all Intellivisions are set to channel 3 and so is my TV. I'm at a loss. What am I forgetting? How is it possible that I now have two Intellivisions that are not outputting a signal? What troubleshooting can I do? I'd appreciate any suggestions. I hate to think I've destroyed both of these units while trying to troubleshoot one of them! Thanks in advance. Quote Link to comment Share on other sites More sharing options...
+intvsteve Posted February 20, 2019 Share Posted February 20, 2019 Have you checked those pesky ribbon cables connecting power to the mainboard? Some recent experiences have shown me that the power LED is kind of wired up ... semi-randomly - so it's possible that the mainboard isn't getting the power it should. Those ribbon cables can be easily damaged. Quote Link to comment Share on other sites More sharing options...
austodd Posted February 20, 2019 Author Share Posted February 20, 2019 (edited) Thanks for your response! Using a multimeter I tested the voltage pins on the CPU, STIC, and SRAM and was able to verify that they are indeed getting power. Plus, those things get hot surprisingly fast! I just can't imagine what I must have done to both of these units to prevent them from outputting a signal. I don't even see a flicker on the TV when I switch on the power. Is it possible I managed to fry both of the RF modulators? Seems unlikely. Is there a good way to test these? Actually I was just looking through the Intellivision service manual and saw that I should be getting +6V DC to the RF modulator, and I verified that I am getting that, so power is definitely making it there. Thanks again for any suggestions. Edited February 20, 2019 by austodd Quote Link to comment Share on other sites More sharing options...
mr_me Posted February 20, 2019 Share Posted February 20, 2019 (edited) The intellivision main circuit board gets five different voltages. When it's not outputting video/audio, power problems is what comes to mind. Edited February 20, 2019 by mr_me Quote Link to comment Share on other sites More sharing options...
+nanochess Posted February 20, 2019 Share Posted February 20, 2019 Is it right the chip orientation in socket? Also make sure you touch something metalic before touching chips. Quote Link to comment Share on other sites More sharing options...
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