frenchguy Posted June 15, 2014 Share Posted June 15, 2014 Hi, As I said in my presentation topic : http://atariage.com/forums/topic/226536-hi-from-france/?do=findComment&comment=3011092 I've got a 7800 with some video problems. I hope I post this topic in the correct forum. Here's the problems : When I play a cartridge (2600 games, I don't own any 7800 game for now), the display is dominantly red/orange, with very visible scanlines (like a very bad filter in some emulation program) and a bit blury too. When I play the internal 7800 game (asteroids), the problems are less important, but the display is still far from being perfect (especially the blur). I tried to move the video cable to see if any diference appears : no diference. So I don't think it's the cable fault. So I dissassembled the console. The video female plug seems in good shape, with all pins firmly attached to the daughter board. The weld points seems a bit dry maybe. I also tried to move the 2 "knobs" on the daughter board, with apparently no effect (difficult to see, because of the awfull red-ish blurry display). Now I'm a bit lost, so I think I'll start by doing new fresh weld points for the video plug. Any help will be appreciated. Many thanks ! Quote Link to comment Share on other sites More sharing options...
frenchguy Posted June 16, 2014 Author Share Posted June 16, 2014 Today I made some screenshots of the console current state. Here's some screenshots of a vcs2600 cart inserted (double dragon). You can see the strong scanline, the blury graphics and the red color everywhere. Here's a screenshot of the 7800 embedded Asteroids game. THe red effet remains, even if it's not as visible. The graphics still blury and scanlined too. I tried to rotate the 2 knobs on the rgb daugther PCB, but with no significant result. If I set them for better 7800 display (less blury especially), 2600 games appears almost in black and white. If I set the knobs for better 2600 display, the 7800 games are awfull. I don't know what to do. I'll try to clean the cart port, and maybe re-do the welding points of the rgb cable plug. But I'm not very confident in the result. Quote Link to comment Share on other sites More sharing options...
roland p Posted June 16, 2014 Share Posted June 16, 2014 (edited) I can't see the pictures. Edit: Now I do see the pictures in the above post. Edited June 16, 2014 by roland p Quote Link to comment Share on other sites More sharing options...
frenchguy Posted June 16, 2014 Author Share Posted June 16, 2014 Strange, I hosted them like I do usually, and they are working for me. Anyway, I uploaded them directly on the forum, now anyone should be able to see them. The very red ones are the 2600 pics, the not so red is the 7800 pic. thanks Quote Link to comment Share on other sites More sharing options...
Thibr Posted June 17, 2014 Share Posted June 17, 2014 Thank you for these pictures frenchguy. I'd say that your TV/monitor may also be involved (the red zone is the center of the picture for your built-in game). Quote Link to comment Share on other sites More sharing options...
frenchguy Posted June 17, 2014 Author Share Posted June 17, 2014 thanks for your answer, The tv is almost brand new, it accepts 50 and 60hz, pal, and ntsc. I use it with all my retro machines (from the master system to the dreamcast), all using RGB scart, with perfect image. I'm afraid the problem is related to the 7800 console. On a french forum some members gave me clues and things to try, I'll try it tommorow and keep you informed. Quote Link to comment Share on other sites More sharing options...
frenchguy Posted June 20, 2014 Author Share Posted June 20, 2014 Is this the first time a 7800 has technical problems ? Quote Link to comment Share on other sites More sharing options...
frenchguy Posted January 8, 2015 Author Share Posted January 8, 2015 Too bad I never found any solution (or help) to fix this console. It will probably go to garbage, finally. Quote Link to comment Share on other sites More sharing options...
roland p Posted January 9, 2015 Share Posted January 9, 2015 Would you sell it? Quote Link to comment Share on other sites More sharing options...
alex_79 Posted January 9, 2015 Share Posted January 9, 2015 I'm not a tech expert, but here's some suggestions:- Try tuning the 2 pots on the 7800 board that control the color, one for 2600 games, the other for 7800 ones. The pots I'm referring to are on the MAIN board, below the cartridge port, not on the RGB daughter board. - Check the cable for continuity (you'll need a multimeter). A broken wire in one of the RGB components cold be the cause for the strange colors. - If the problem is in the RGB daughter board and you can't fix it, but you have some soldering experience, then you could just disable it and install one of the A/V mods on your console (which is based on the PAL version). The "easier composite mod" that you find in the forum is very easy to do and gives good results (at least on CRT TVs). If you wants better quality you should go for an s-video mod. After the mod the console will be PAL, so you need a TV which accepts a PAL signal. Quote Link to comment Share on other sites More sharing options...
frenchguy Posted January 10, 2015 Author Share Posted January 10, 2015 Thank you for your help, it's the kind of help I was hoping for. I'll try your advises, and come back here with result ! Quote Link to comment Share on other sites More sharing options...
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