Mick_AA_76 Posted March 19, 2019 Share Posted March 19, 2019 Hi, Ive just joined and Im after some advice please - Ive got a light sixer that I bought quite a while back but have only just got around to testing it - initially for the life of me I couldnt get it tuned into either of my TVs (Im in the UK so its PAL via RF cable). I put it down to newer lcds having rubbish analogue tuners so tried an old crt and could still only manage similar results to my 2 lcds - couldnt get it locked into a strong signal and could only manage to get a slow rolling fuzzy image. So having a bit of an interest / hobby with electronics Ive done an A/V mod, and also re-capped it, but I still have the same issue , albeit with a nice, clearer view of the fault ?. The problem occurs on all of the carts Ive tried, and Ive googled / searched YouTube for a similar issue but Ive not seen anything exactly the same - Ive linked to some YouTube vids below that Ive uploaded... any ideas? Cheers, Mick Quote Link to comment Share on other sites More sharing options...
AkashicRecord Posted March 19, 2019 Share Posted March 19, 2019 I'd probably suspect the TIA chip is at fault, but maybe someone with more repair experience can chime in. At least it should be socketed on that model, so it should be easy and quick to replace... Quote Link to comment Share on other sites More sharing options...
+-^CrossBow^- Posted March 20, 2019 Share Posted March 20, 2019 My first guess is the TIA as well because the music on ET doesn't sound correct either. From there replace the RIOT next. Quote Link to comment Share on other sites More sharing options...
AkashicRecord Posted March 20, 2019 Share Posted March 20, 2019 (edited) Now that you mention the RIOT chip, that's a definite possibility with the obvious timing issues in those video examples...but I'm still suspecting the TIA. Edited March 20, 2019 by AkashicRecord Quote Link to comment Share on other sites More sharing options...
+save2600 Posted March 20, 2019 Share Posted March 20, 2019 Have you tried reseating the TIA, etc.? Quote Link to comment Share on other sites More sharing options...
Mick_AA_76 Posted March 20, 2019 Author Share Posted March 20, 2019 Thanks for the replies everyone, I have tried re-seating all 3 chips but I didnt spend any time cleaning pins / sockets so Ill give that another try ? I do also have a 4 switch Vader model - also faulty though but that seems to be a power issue - Ive read that the various revisions of the TIA / RIOT / CPU are compatible across models - is that correct? Also are they socketed on the Vaders? Thanks again ? Mick Quote Link to comment Share on other sites More sharing options...
+-^CrossBow^- Posted March 20, 2019 Share Posted March 20, 2019 I don't believe they are socketed on the vaders but then it has been more than a few years since I took one apart to check. I did just remove the TIA and RIOT from another light 4 switcher and they weren't in sockets. As for different revisions of the chips, yes especially the TIA. And if you should replace the TIA and it fixes the issues, don't be surprised if you have to re-adjust the colors after. Seems I always have to do this when replacing a TIA. Just had to go through this on a Sears Video Arcade 2 this past weekend. Quote Link to comment Share on other sites More sharing options...
Mick_AA_76 Posted March 21, 2019 Author Share Posted March 21, 2019 (edited) Well I tried re-seating the three chips and giving them a bit of a clean in the process but thats not fixed it ? The Vaders chips arent socketed but as thats also got a fault that Ive not 100% pinpointed the issue on Im not gonna start swapping out potentially faulty chips from that - its main issue is it doesnt power on, or output anything to the tv - checking the voltages at the regulator shows about 4v input and about 2v output - Im going to replace the regulator first before I go looking for what could be shorting - I checked all the chips on the board and none of them were even warm (apart from the regulator which did heat up a lot quicker than it should) Thanks again for your help ? Mick Edited March 21, 2019 by Mick_AA_76 Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted March 21, 2019 Share Posted March 21, 2019 (edited) The specifics of the problem seem centered around the data lines. The music is vaguely correct, but notes are off. The VSYNC/VBLANK are incorrectly set, causing a constant roll. The screen seems to be mirrored, and the graphics are kinda-sorta right. But the system is basically functional. This suggests that either some data lines on the TIA are not making contact, or they are just dead inside. Certainly the pin labeled D1, since it's needed for the VBLANK and VSYNC programming. Edited March 21, 2019 by ChildOfCv Quote Link to comment Share on other sites More sharing options...
Mick_AA_76 Posted March 22, 2019 Author Share Posted March 22, 2019 The specifics of the problem seem centered around the data lines. The music is vaguely correct, but notes are off. The VSYNC/VBLANK are incorrectly set, causing a constant roll. The screen seems to be mirrored, and the graphics are kinda-sorta right. But the system is basically functional. This suggests that either some data lines on the TIA are not making contact, or they are just dead inside. Certainly the pin labeled D1, since it's needed for the VBLANK and VSYNC programming. Thanks for this... I did do a visual check of the soldering which looked ok but Ill double check these pins ? Quote Link to comment Share on other sites More sharing options...
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