BSA Starfire Posted February 26, 2013 Share Posted February 26, 2013 Hi all, my PAL light sixer is rather unwell. The machine runs games OK but the video output is all messed up. The picture is black and white, with color accasionally showing, as does the audio. The picture rolls then stabalizes. I have cleaned all the switches witch were pretty grotty along with the cart port and all seem good now. I'm using a known good power supply and RF cable, clean game carts etc(I also own a Jnr and 7800). Using the same CRT telly that is fine with the jnr and 7800. I have taken a video on my phone, will find somewhere to upload it ASAP and post a link, it's too big to upload here. Any help much appreciated. Best regards, Chris Oh right I'm in the UK so everything is PAL, console, TV carts etc. Quote Link to comment Share on other sites More sharing options...
BSA Starfire Posted February 26, 2013 Author Share Posted February 26, 2013 Here's link to video of what's going on. Best, Chris Quote Link to comment Share on other sites More sharing options...
0078265317 Posted February 26, 2013 Share Posted February 26, 2013 Weird. Definately something internal wrong. I have no clue however. But someone here will hopefully. Quote Link to comment Share on other sites More sharing options...
31336haxx0r Posted February 26, 2013 Share Posted February 26, 2013 (edited) If I remember this right, then there is an adjustable coil in the RF modulator part of the PCB. You could try adjusting that. Edit: did you try out the TIA chip of that console in a different, known working console? Edited February 26, 2013 by 31336haxx0r Quote Link to comment Share on other sites More sharing options...
Mike OC Posted February 26, 2013 Share Posted February 26, 2013 Looks like a bad 7805 voltage regulator. I'd start there as they are cheap to replace. http://datasheetreference.com/images/stories/7805-regulator-picture.jpg Quote Link to comment Share on other sites More sharing options...
BSA Starfire Posted February 26, 2013 Author Share Posted February 26, 2013 If I remember this right, then there is an adjustable coil in the RF modulator part of the PCB. You could try adjusting that. Edit: did you try out the TIA chip of that console in a different, known working console? Thanks, tried the modulator, only other console I have is Jnr, has soldered TIA so can't try change. Looks like a bad 7805 voltage regulator. I'd start there as they are cheap to replace. http://datasheetrefe...tor-picture.jpg OK thanks, this looks simple enough to change, will try and track down part, no Radio Shack here anymore & CPC is long drive. Best, Chris Quote Link to comment Share on other sites More sharing options...
shadow460 Posted February 27, 2013 Share Posted February 27, 2013 (edited) I'm thinking it's the TIA itself. You can try turning the color adjustment pot and see if that cleans things up, but I doubt it will. A bad 7805 will not produce any change at all on the TV. You can check the 7805 with a voltmeter. With the power adapter plugged in, you should get 9 to 13 volts to ground on one leg, 5 volts on the second, and 0 volts on the third because it's the ground. While you're in there, check the ribbon cable that connects the two circuit boards. I had one break on me one time and the console went absolutely nuts until I fixed it. You will have to set the color pot to match the replacement TIA. If you try swapping the TIA from another console, the colors will be wrong on both until you either adjust the pots or swap them back. At least it'll tell you if the chip itself is bad. The 7800 also has a TIA IIRC (please correct me if I'm wrong!). My 7800 has all soldered ICs, though, and the 7800 is not easy to open without breaking something. I have a TIA in my pile of parts, but the colors on it "roll" slightly. It's not something I'd install into a working console, but it would be OK for testing purposes. It definitely doesn't roll like your console does. Edited February 27, 2013 by shadow460 Quote Link to comment Share on other sites More sharing options...
BSA Starfire Posted February 27, 2013 Author Share Posted February 27, 2013 Thanks shadow460. Checked the VRM with a meter, it's as it should be. Looks like it's the TIA at fault. Are PAL & NTSC TIA's the same? If so I could use that TIA you have spare. Best, Chris Quote Link to comment Share on other sites More sharing options...
shadow460 Posted February 28, 2013 Share Posted February 28, 2013 I'm not 100% sure if they are, but if you wanna try it, shoot me a PM. Quote Link to comment Share on other sites More sharing options...
BSA Starfire Posted February 28, 2013 Author Share Posted February 28, 2013 I'm not 100% sure if they are, but if you wanna try it, shoot me a PM. Thanks shadow, bit of research and it seems the NTSC & PAL tia's have different pin-outs sadly. If anyone has a spare PAL tia, I would be most grateful, probably could find something neat to trade. All the best, Chris Quote Link to comment Share on other sites More sharing options...
Serious Posted March 1, 2013 Share Posted March 1, 2013 Given the higher number of scan lines on a PAL display, I would guess the TIAs would have to be different. Quote Link to comment Share on other sites More sharing options...
shadow460 Posted March 2, 2013 Share Posted March 2, 2013 We tried. Quote Link to comment Share on other sites More sharing options...
31336haxx0r Posted March 2, 2013 Share Posted March 2, 2013 PAL & NTSC TIAs are indeed different. I have a spare PAL TIA around, if you need one. Quote Link to comment Share on other sites More sharing options...
BSA Starfire Posted March 3, 2013 Author Share Posted March 3, 2013 That would be brilliant, much appreciated. Be nice to get it working again. Should I PM you? Best, Chris Quote Link to comment Share on other sites More sharing options...
31336haxx0r Posted March 3, 2013 Share Posted March 3, 2013 You can PM me anytime. 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.