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Posted Sat Apr 30, 2016 6:54 PM
Posted Sat Apr 30, 2016 7:28 PM
I'm no expert, and off the top of my head I don't recall any real issues. But I did have something similar happen! For me it was 2 dots or slashes that would appear after the word JOUST on the Joust homebrew title screen. If the dots or slashes appear, the game would often glitch into weird, messed up graphics afterwards. Somehow I figured out it was a Power Supply issue (even though everything seems tight). Yours might be something completely different. What I do is put just a little weight on the power supply cord coming out of the CV, and then the dots/slashes disappear and the game works fine. For mine even just a little bit of weight (like a cartridge or an NES controller, anything really) did the trick. You might try lightly holding in your power supply cord when turning it on and try putting just a little weight on it at various angles and see if anything happens.
Posted Sat Apr 30, 2016 7:30 PM
No this is not normal.
Btw the Ben heck mod uses a transistor. A better mod uses the LM318.
Same as most hook the audio direct to the chip, this can pass on dc voltage. A better audio attachment point is RF side of C88.
Your video issue could be a couple of things. Bad vram or dirty cartridge connector. Clean your power switch and cartridge connector.
Part 8 right near the end shows what it might look like on the title screen.
Edited by cdn2a, Sat Apr 30, 2016 7:34 PM.
Posted Sat Apr 30, 2016 7:47 PM
Posted Mon May 2, 2016 1:28 PM
So I decided to tinker with my CV a bit more today. I moved the audio-out connection from the chip to the C88 capacitor, and I cleaned the cartridge slot connectors as best as I could.
Result: same exact issues as before. At least my audio is better configured for if/when I get an expansion module. Looks like I'll have to get a replacement cartridge slot, maybe?
So then I decided to try and clean the cartridge connectors on the only non-working game I own (Ladybug). This is where things went reeeeeeally wrong (because I'm a doofus). After removing the board from the cartridge case and cleaning everything thoroughly, I decided to leave the board out (in case the problem needed more solving), which is fine!...as long as you don't insert the cartridge in reverse. Eerie, Atari-esque, "not working" sound (you all know the sound). Immediately powered the CV off, said "oops", and then went to a working cartridge. Nothing. I'm preeeeetty sure I shorted something; power supply? cartridge slot? both? other things? I'm not sure.
This is obviously going to be a much more involved project, for another day. In the meantime, if any of you have any tips on what I can do to save my console, that'd be great. Please be gentle; I know I'm a dummy here. Thanks!
Posted Mon May 2, 2016 5:03 PM
Check the voltages out of the powersupply, power it on and see if you get a bios splash screen.
Posted Fri Jun 8, 2018 12:02 AM
Edited by HeadcolorsTV, Fri Jun 8, 2018 12:06 AM.
Posted Fri Jun 8, 2018 5:47 AM
Posted Fri Jun 8, 2018 7:02 AM
Posted Fri Jun 8, 2018 8:58 AM
Posted Fri Jun 8, 2018 9:07 AM
Posted Fri Jun 8, 2018 9:10 AM
Posted Fri Jun 8, 2018 2:45 PM
Posted Fri Jun 8, 2018 8:19 PM
A couple of those voltages coming out of the RF box seem a tad high. The 12 v tap on the bottom right is normal but the audio and video points don't seem right. I've never had 12 volts coming out of those signal points. My readings generally run around 8 - 8.5 volts for the audio point and 5 - 5.5 volts on the composite point.
Posted Fri Jun 8, 2018 8:44 PM
Posted Fri Jun 8, 2018 8:58 PM
Posted Fri Jun 8, 2018 9:00 PM
I don't think the modchip is the problem. It's possible, but I think your problem is in the motherboard somewhere.
Posted Fri Jun 8, 2018 9:02 PM
Posted Fri Jun 8, 2018 9:07 PM
It's not, the video tap on the RF module (before the retrofix modboard) is pushing 12 volts. Shouldn't be that high, should be around 5 to 6 volts.
Posted Fri Jun 8, 2018 9:09 PM
Posted Sat Jun 9, 2018 12:30 AM
Edited by HeadcolorsTV, Sat Jun 9, 2018 12:32 AM.
Posted Sat Jun 9, 2018 12:41 AM
Ah okay, no worries man. I was just going by your pic and you had 12v listed on each of the taps. However that's good that your voltages are good and you hooked the modboard up properly according to your pictures as well. I'm curious, does RF still work?
Edit: I'm up late working too haha
Edit 2: Let me hook back up my diagnostic Coleco and I'll measure the voltages on my LM318 and see if they match yours. Give me a few minutes.
Posted Sat Jun 9, 2018 12:57 AM
On my LM318 here are the voltages I'm getting. Hopefully this can help by giving you something to compare to.
Pin 1 = 9.14 v
Pin 2 = 5.69 v
Pin 3 = 5.69 v
Pin 4 = 0
Pin 5 = 9.15 v
Pin 6 = 5.69 v
Pin 7 = 11.49 v
Pin 8 = 1.35 v
I might be wrong but it might be possible that the lm318 was maybe installed backwards? Is there a silkscreen marking on the modboard showing which way the LM318 should be facing? Or that chip might just be bad period.
Edit: Okay, I went to retrofixes website and looked at a picture of their amp board. It appears from their pic and yours that everything on the modboard itself is installed right.
Posted Sat Jun 9, 2018 7:30 AM
Going back to 2016...
The issue with the corrupted vertical line of graphics would most likely have been an issue with the power supply, power switch or RAM chips.
Now in 2018...
Could the issue be the VDP chip? I would also inspect all traces on the CV motherboard, especially those dealing with the VDP. Do yourself a favor and remove the Retrofixes mod and test the original system again using RF output. I know you didn't get any picture back in 2016, but you could start a game with the controller and did get audio from the Donkey Kong game. If the game starts and you got audio playing, then we know the original issue is with the RF board or the VDP.
Just my two sense here and this is not a knock on the Retrofixes composite mod board, but I still don't understand why everyone doesn't use the Yurkie Composite Mod Board. It is such a well designed, small and clean install compared to others that I have seen.
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