Haydino Posted October 27, 2016 Share Posted October 27, 2016 Hi all, I picked up a VGS from a carboot for £20. So I plugged it all in and I managed to get it tuned correctly etc. However when I turn it on, the colour comes through strange. ( I am running it through an old Game/TV converter that I've had for years, I aim to replace this for a coaxial converter). The main issue that I have is when I play the console with just one controller in, It works okay, However when plugging in the 2nd controller into the port it will fuzz and then cut out. Does anyone have any ideas? Quote Link to comment Share on other sites More sharing options...
Haydino Posted October 28, 2016 Author Share Posted October 28, 2016 Can no one help me out with this? Quote Link to comment Share on other sites More sharing options...
fluxit Posted October 28, 2016 Share Posted October 28, 2016 Check the joystick port for bent pins. Try a different joystick. You didn't mention which type of controller you were using, it may or may not make a difference. Quote Link to comment Share on other sites More sharing options...
Jeremy Popp Posted October 28, 2016 Share Posted October 28, 2016 Maybe as you're plugging in the controller, it also manages to wiggle the power cable which causes cutouts. With no controllers plugged in, I would turn it on and wiggle the power cable near the console and see if it cuts in/out. Alternately, swap controllers around and see if it makes any difference. Quote Link to comment Share on other sites More sharing options...
Haydino Posted October 28, 2016 Author Share Posted October 28, 2016 I'm using Sega Megadrive controllers, It never came with the orginal joysticks, I shall give this a try and tell you how I get on. It seems to happen as soon as you go to push the controller in when the pins make contact with the plug. Quote Link to comment Share on other sites More sharing options...
Keatah Posted October 28, 2016 Share Posted October 28, 2016 Then there is a short someplace. OR a loose connection wiggling around. try a different joystick. and report back. We'll go through it step-by-step. 1 Quote Link to comment Share on other sites More sharing options...
R.Cade Posted October 28, 2016 Share Posted October 28, 2016 Don't Megadrive controllers short GND to +5V on the Atari when certain buttons are pressed? Quote Link to comment Share on other sites More sharing options...
Haydino Posted October 28, 2016 Author Share Posted October 28, 2016 (edited) I booted up the console and then jiggled the power cord lightly. It seems to flicker and fuzz, almost cutting out like no power it getting through. I then tried (when it was getting power okay etc.) plugging in another 3rd party joystick I had into the second port and it fuzzed and cut out. TV then says No signal, like there is no power to the 2600. which must mean it is shorting out? Edited October 28, 2016 by Haydino Quote Link to comment Share on other sites More sharing options...
Keatah Posted October 28, 2016 Share Posted October 28, 2016 (edited) Does plugging that joystick into the other 1st socket do the same thing? Edited October 28, 2016 by Keatah Quote Link to comment Share on other sites More sharing options...
Haydino Posted October 28, 2016 Author Share Posted October 28, 2016 (edited) Does plugging that joystick into the other 1st socket do the same thing? Nope, It seems to be linked to just the right controller socket. Edited October 28, 2016 by Haydino Quote Link to comment Share on other sites More sharing options...
Keatah Posted October 28, 2016 Share Posted October 28, 2016 (edited) Ok. 1- Are all the pins straight and in order? 2- Does pressing on the socket/port itself with the same amount of force cause a problem? 3- Am I correct in assuming that both controllers behave the same way when plugged into the right port? They both cause the issue in the same way? 4- Am I also correct in assuming that the console itself is going through a complete reset (like power off/on) and not just a temporary drop in the video signal? Edited October 28, 2016 by Keatah Quote Link to comment Share on other sites More sharing options...
Keatah Posted October 28, 2016 Share Posted October 28, 2016 Don't Megadrive controllers short GND to +5V on the Atari when certain buttons are pressed? Maybe, maybe not, I don't recall. But that would be irrelevant according to the OP. He says it happens as soon as the plug is inserted into port just enough to make contact. I would assume as that's happening, the controller is sitting on the table with no buttons being pressed. Quote Link to comment Share on other sites More sharing options...
Haydino Posted October 28, 2016 Author Share Posted October 28, 2016 (edited) Maybe, maybe not, I don't recall. But that would be irrelevant according to the OP. He says it happens as soon as the plug is inserted into port just enough to make contact. I would assume as that's happening, the controller is sitting on the table with no buttons being pressed. You do indeed assume correct 1. all the pins are straight. 2. I shall have to check 3.both controller do behave the same way when plugged into the right port. 4. It seems as if the signal drops then it powers off. Edited October 28, 2016 by Haydino Quote Link to comment Share on other sites More sharing options...
Keatah Posted October 29, 2016 Share Posted October 29, 2016 That the controllers cause a problem on the right port, but not the left port, tells me there is a problem inside the console. There is little or no difference in how the ports are wired up in the console, they both go to the TIA and RIOT. There are some resistors and capacitors, too, in parallel with the ports, which could be causing an issue. The right controller port has an additional capacitor in some models, connected to pin 8 of RIOT (pin 1 of the controller socket). Whether this makes a difference with non-standard controllers I have no idea. I think we should test both ports with original controllers. Preferably Joysticks and Paddles. Not forgetting paddles 3 & 4 on the right port. This means something like Warlords or Video Olympics will be needed to verify all 4 paddles. A good visual inspection to ensure that nothing is shorting against shielding, and that there are no cracked solder joints in the area, also needs to be done. Then move on to 3rd party and non-standard controllers.. If any chips are going to be replaced it'll likely be TIA or RIO, but that has yet to be determined. Quote Link to comment Share on other sites More sharing options...
Keatah Posted October 29, 2016 Share Posted October 29, 2016 It also would be useful to see what kinds of voltages are on both sets of pins in the ports. And also their resistances when the unit is turned off. A basic DMM will be required. I'd be looking for comparisons between the left and right ports. Whatever the values may be, they should be the same for both. Such is the nature of step-by-step troubleshooting. Barring specific knowledge of "this symptom = that problem" things just have to be worked through. If anyone has seen this exact situation before, then great! We can get right to cause and do a fix now. Quote Link to comment Share on other sites More sharing options...
zylon Posted October 31, 2016 Share Posted October 31, 2016 Is this a 6-switch console? Quote Link to comment Share on other sites More sharing options...
Haydino Posted October 31, 2016 Author Share Posted October 31, 2016 Yes, it is indeed a 6-switch console, keatahI shall get back to with with those reports later in the week! Quote Link to comment Share on other sites More sharing options...
zylon Posted November 2, 2016 Share Posted November 2, 2016 Yes, it is indeed a 6-switch console, keatahI shall get back to with with those reports later in the week! Might have a dead short in the hex buffer. Another possibility is a short at the port to board solder joints. I have seen some nasty work on those towards the end of their production. Quote Link to comment Share on other sites More sharing options...
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