Kernel Posted June 25, 2020 Share Posted June 25, 2020 (edited) Yes, another thread on this...apologies in advance if I have not dug enough. I am trying to troubleshoot my CV that has glitching as these pics show: https://imgur.com/3Mn6tbv https://imgur.com/Escq53k I know the power supply is fine as I've tested it, but I also purchased a COLUSB on the off chance I was not using the multi-meter correctly. I'm still a novice at this sort of stuff. I've also un-soldered, trimmed/cleaned the power cables and re-attached them to no avail (the ground had what looked like corrosion on it, so figured it was worth a try). I know that this could be anything really, so before I pull off the power switch and try that fix, and before I pull the RAM and try that, and before I try to replace the video chip, what I'm looking for is some guidance on where I should test for power on the board to ensure it's flowing properly. I've found the technical manual and schematics by way of the god that is google, but other than 2 other threads here, I have not found info on how to test the various chips for proper connectivity. I'm thinking I just haven't looked int he right place. The threads I've seen so far that have some info that I am going to try are: ^^ I have a logic probe on the way so I can complete this step. Any help/pointers would be appreciated. I know I can buy a new one from ebay and probably just move on, but I really want to be able to save this thing and hone my troubleshooting and soldering skills. Thanks. Edited June 25, 2020 by Kernel Quote Link to comment Share on other sites More sharing options...
+-^CrossBow^- Posted June 25, 2020 Share Posted June 25, 2020 Well, the switch is the first thing to try and you would be amazed as how often it helps fixes some of the graphic issues. Also, have you tried to move the power cord around or jiggle the power plug while plugged into the CV? Mine initially had some corrosion on the ends of the pins on power port on the console and once I cleaned them up I had a much more stable picture. I might have also gone ahead and soldered the wiring onto the back of the pegs on that port as well now that I think about it to be sure they had a secure connection. Quote Link to comment Share on other sites More sharing options...
Retro_Game_Lover96 Posted June 25, 2020 Share Posted June 25, 2020 1 hour ago, Kernel said: Yes, another thread on this...apologies in advance if I have not dug enough. I am trying to troubleshoot my CV that has glitching as these pics show: https://imgur.com/3Mn6tbv https://imgur.com/Escq53k I know the power supply is fine as I've tested it, but I also purchased a COLUSB on the off chance I was not using the multi-meter correctly. I'm still a novice at this sort of stuff. I've also un-soldered, trimmed/cleaned the power cables and re-attached them to no avail (the ground had what looked like corrosion on it, so figured it was worth a try). I know that this could be anything really, so before I pull off the power switch and try that fix, and before I pull the RAM and try that, and before I try to replace the video chip, what I'm looking for is some guidance on where I should test for power on the board to ensure it's flowing properly. I've found the technical manual and schematics by way of the god that is google, but other than 2 other threads here, I have not found info on how to test the various chips for proper connectivity. I'm thinking I just haven't looked int he right place. The threads I've seen so far that have some info that I am going to try are: ^^ I have a logic probe on the way so I can complete this step. Any help/pointers would be appreciated. I know I can buy a new one from ebay and probably just move on, but I really want to be able to save this thing and hone my troubleshooting and soldering skills. Thanks. I fixed my ColecoVision graphics with the 5v Ram mod and replacing the power switch. Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted June 25, 2020 Share Posted June 25, 2020 (edited) 1 hour ago, Kernel said: I am trying to troubleshoot my CV that has glitching as these pics show: https://imgur.com/3Mn6tbv https://imgur.com/Escq53k That particular corruption looks more like the character set is corrupt. The text itself is correct, mostly. The character set comes from ROM. I'd check the ROM chip. Well, on the other hand, a RAM chip doesn't always die completely. It could just be selectively dead in places, and that could result in similar corruption. If you actually start a game, does it play properly? Do the non-text graphics glitches continue? Edited June 25, 2020 by ChildOfCv Quote Link to comment Share on other sites More sharing options...
Kernel Posted June 26, 2020 Author Share Posted June 26, 2020 3 hours ago, -^CrossBow^- said: Well, the switch is the first thing to try and you would be amazed as how often it helps fixes some of the graphic issues. Also, have you tried to move the power cord around or jiggle the power plug while plugged into the CV? Mine initially had some corrosion on the ends of the pins on power port on the console and once I cleaned them up I had a much more stable picture. I might have also gone ahead and soldered the wiring onto the back of the pegs on that port as well now that I think about it to be sure they had a secure connection. Do you recall how you cleaned the posts? There was a little interference when wiggling the cables at least before I re-soldered them on at the motherboard, but I have not really tested it much since I did this last night. Wonder if someone makes a replacement power port... the COLUSB is only the plug from the power adapter. If there was a replacement power port that would be another thing to rule out totally. Quote Link to comment Share on other sites More sharing options...
Greg2600 Posted June 26, 2020 Share Posted June 26, 2020 (edited) https://console5.com/techwiki/images/e/ec/Colecovision_Technical_Manual.pdf The old tech manual has examples for each graphical problem and what to change, beginning on page 79 of the PDF. Not sure how accurate it is now. Edited June 26, 2020 by Greg2600 Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted June 27, 2020 Share Posted June 27, 2020 On 6/25/2020 at 7:30 PM, Kernel said: Do you recall how you cleaned the posts? There was a little interference when wiggling the cables at least before I re-soldered them on at the motherboard, but I have not really tested it much since I did this last night. Wonder if someone makes a replacement power port... the COLUSB is only the plug from the power adapter. If there was a replacement power port that would be another thing to rule out totally. Deoxit is a common way to clean pins. Spray some, then plug and unplug a few times. Quote Link to comment Share on other sites More sharing options...
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