theor Posted June 28, 2018 Share Posted June 28, 2018 (edited) Hi everyone, I've purchased and restored a light sixer, but I think it may be broken. Here's the kind of output I get when I turn it on, either with a cartridge or not: - black screen with a static white bar on the left - wriggling white bars - jumping and wriggling rainbow lines (with sound) I can record a short video if that would help. Of course I've cleaned the cartridge and the connector before going further. When I received it, the motherboard was covered with brown glue residues, typical of the late 70s and early 80s PCBs. I understand this glue turns conductive and corrosive with time and indeed some tracks were wrinkled, so I carefully removed the glue with white gas (naphta), isopropyl alcohol and an old toothbrush. The PCB looks somewhat OK now without the glue, expect for those wrinkled tracks and the tarnished look: Next I replaced the 7805 voltage regulator, lifted and reseated the RIOT, 6507 and TIA. The chips all run somewhat hot, the RIOT even uncomfortably hot after a while, although I can't conclude yet it's dead. Also I don't have a VCR or a CRT TV, I'm using an RF to VGA adapter (which might be a problem itself, although unlikely I think). Hopefully it's not beyond repair. How should I diagnose the problem from there? Thank you Edited June 28, 2018 by theor Quote Link to comment Share on other sites More sharing options...
Keatah Posted June 28, 2018 Share Posted June 28, 2018 The wrinkles tracks are totally ok. It's just extra solder and air wicking underneath. Quote Link to comment Share on other sites More sharing options...
+-^CrossBow^- Posted June 28, 2018 Share Posted June 28, 2018 Yeap...the wrinkling is totally normal on those old systems. Also the 'glue' you speak of is actually solder flux and yes it does tend to be quite gooped in places on those old boards. It isn't that critical that is be removed as it doesn't really become conductive so much as it can eat at the traces over time in large amounts. You're removal process was right on for that. I would suspect the RIOT or TIA first as being bad. Usually the TIA just gives a black screen, so I would go with the RIOT first. The 6502 can go bad as well, but I don't know that I've actually had one go bad yet. For me the TIAs are the most prone to failure followed by the RIOT. Quote Link to comment Share on other sites More sharing options...
Keatah Posted June 28, 2018 Share Posted June 28, 2018 A first step in digital troubleshooting is to check for a clock. And then activity on address/data lines. And also the reset circuit. Of course all that is done after you verify clean and in-spec power getting to each IC. Quote Link to comment Share on other sites More sharing options...
theor Posted June 28, 2018 Author Share Posted June 28, 2018 Thanks for your answers, that's a good thing to hear about the PCB. Good news about the flux also, I feared it was this dreaded glue.So I gave it another try and realized the cartridge wasn't pushed all the way down the connector. When I did, I got some kind of picture, so my VCS is fine. Hooray!Yet this surprised me as I really applied a lot of force on the cartridge earlier, and when I reassembled everything, I realized the cartridge, Solaris, won't even go half way down the slot! I almost had to pry on the console to take it out and the cart edges have been damaged a little... I guess I'll have to sand the aluminum slot a little, it's way too tight a fit.So now here's what I get :Some possibilities now include a faulty RF cable, or an NTSC game since I have a PAL VCS. There's no clue on the label whether its NTSC or PAL.It may also come from this MTVBox RF to VGA adapter device. It would make sense because as I fiddled with the settings, I got a black and white picture at some point (and some noise coming out of the speakers). I barely had the time to take a screenshot:I think I'll have to try with another game and with an actual CRT monitor. But at least my VCS is fine, I'm relieved. Quote Link to comment Share on other sites More sharing options...
Jstick Posted June 29, 2018 Share Posted June 29, 2018 Solaris, won't even go half way down the slot! I almost had to pry on the console to take it out and the cart edges have been damaged a little... I guess I'll have to sand the aluminum slot a little, it's way too tight a fit. Solaris is a late ‘80s cart, the sixers’ slots have trouble with some of those 7800 era games (thicker shell I believe?). Quote Link to comment Share on other sites More sharing options...
+Stephen Moss Posted June 29, 2018 Share Posted June 29, 2018 The chips all run somewhat hot, the RIOT even uncomfortably hot after a while, although I can't conclude yet it's dead. Are you sure you replaced them the right way round, putting them in the wrong way around usual them rather toasty Quote Link to comment Share on other sites More sharing options...
theor Posted June 29, 2018 Author Share Posted June 29, 2018 I didn't remove the chips completely, just enough to lift them up and put them back to scrub away some potential corrosion. Besides I doubt I would be getting a picture if I had put it the wrong way. I'm leaning toward the LCD monitor, it probably doesn't like the VCS and won't sync with it. I don't want to mod my VCS, so unless someone knows an alternative I'll probably need to buy a small CRT TV, or at least a proper LCD TV (not a computer monitor with an RF adapter). I was hoping to save space but probably expected too much from the RF adapter. Here's the adapter in action, it sounded like a nice idea: https://nintendosegajapan.com/2015/10/22/how-to-play-ntsc-j-rf-only-consoles-on-pal-televisions/ Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted June 29, 2018 Share Posted June 29, 2018 The 6502 can go bad as well, but I don't know that I've actually had one go bad yet. For me the TIAs are the most prone to failure followed by the RIOT. This is an aside, but I have a 2600 (a 4-Switch Woody, to be exact) that had a bad 6507. I also have a 1200XL that had a bad 6502C SALLY. Quote Link to comment Share on other sites More sharing options...
jc13 Posted June 30, 2018 Share Posted June 30, 2018 Yet this surprised me as I really applied a lot of force on the cartridge earlier, and when I reassembled everything, I realized the cartridge, Solaris, won't even go half way down the slot! I almost had to pry on the console to take it out and the cart edges have been damaged a little... I guess I'll have to sand the aluminum slot a little, it's way too tight a fit. I've run into this before too, and found that if you put a cartridge in the slot before you tighten the screws holding the board to the aluminum housing you can shift things around enough to make it work - no sanding required! 1 Quote Link to comment Share on other sites More sharing options...
theor Posted July 1, 2018 Author Share Posted July 1, 2018 The board makes an electrical contact with the PCB ground so I didn't want to keep the contact loose or mess with it. The good news is it only took little sanding to insert the cartridge effortlessly. There was just one tight spot, near the top left corner, and 10mn of sanding later the friction was completely gone! Unfortunately I still have an issue with those red label carts: they won't open the flap soon enough, so the connector gets blocked by the flap instead of inserting. Inserting the cart diagonally isn't possible when the aluminum housing is mounted, so I have to keep the flap open with a cable tie before inserting the cart. No problem with the black label carts. Apparently there seems to be a dimensional tolerance issue with the sixers and red label carts. Quote Link to comment Share on other sites More sharing options...
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.