critanime Posted October 17, 2009 Share Posted October 17, 2009 Hi all. Long time lurcher and first time poster (always wanted to say that ). Just bought a 7800 off ebay for £40 boxed with 10 games all boxed . Am loving the system and love the variety of the games on it. However I am a little disturbed. I bought it mainly because of the prospect of been able to play most Atari 2600 games. This filled me with joy as I have a collection of games and a really ailing 2600 that is in need of retirement after 28 years. Unfortunately for some reason, whenever I put in a 2600 game, the graphics are really blurry and ghosting. I have tried it on 3 TV's to make sure it wasn't just the set and on all three it was the same. So unfortunately my first post is a big cry for HELP! I have popped the case open to see if there is anything noticeable that could be repaired. Unfortunately I can't find anything wrong with the motherboard. I do know that the system is the rev c one if that helps. Also Haunted House seems to be acting strange on the system. It shows the walls as they should be yet the character moves like the walls have moved about 2 centimeters to the right. Please help. James. Quote Link to comment Share on other sites More sharing options...
Mord Posted October 17, 2009 Share Posted October 17, 2009 I bought it mainly because of the prospect of been able to play most Atari 2600 games. This filled me with joy as I have a collection of games and a really ailing 2600 that is in need of retirement after 28 years. Unfortunately for some reason, whenever I put in a 2600 game, the graphics are really blurry and ghosting. I have tried it on 3 TV's to make sure it wasn't just the set and on all three it was the same. So unfortunately my first post is a big cry for HELP! The only idea I have is that there might be something wrong with the TIA on the motherboard since it handles the 2600 games. I haven't tried any 2600 games on my 7800 to see if it behaves similarly and can't right now due to having the system packed away. Hopefully someone else can be more helpful. Quote Link to comment Share on other sites More sharing options...
critanime Posted October 18, 2009 Author Share Posted October 18, 2009 The only idea I have is that there might be something wrong with the TIA on the motherboard since it handles the 2600 games. I haven't tried any 2600 games on my 7800 to see if it behaves similarly and can't right now due to having the system packed away. Hopefully someone else can be more helpful. Whats the TIA? Quote Link to comment Share on other sites More sharing options...
Mord Posted October 18, 2009 Share Posted October 18, 2009 The only idea I have is that there might be something wrong with the TIA on the motherboard since it handles the 2600 games. I haven't tried any 2600 games on my 7800 to see if it behaves similarly and can't right now due to having the system packed away. Hopefully someone else can be more helpful. Whats the TIA? Television Interface Adapter. It's what was in the Atari 2600 for handling graphics. To get backwards compatibility on the 7800, they just plopped one of those on the motherboard. Quote Link to comment Share on other sites More sharing options...
critanime Posted October 18, 2009 Author Share Posted October 18, 2009 Television Interface Adapter. It's what was in the Atari 2600 for handling graphics. To get backwards compatibility on the 7800, they just plopped one of those on the motherboard. Ah right. Well I have just notice that on playing 7800 games I get a bit of banding on that. It's only slight and hardly noticeable but it's there. So I am wondering if there is something wrong with the rf modulator. Also when I had the case open I noticed two silver discs that look like they could be twisted. Could they have anything to do with it because upon reading about the s-video mod (which I am thinking of doing or finding someone in the UK that would do it) you are supposed to twist and turn them to tune it in of sorts. Quote Link to comment Share on other sites More sharing options...
Mord Posted October 18, 2009 Share Posted October 18, 2009 Television Interface Adapter. It's what was in the Atari 2600 for handling graphics. To get backwards compatibility on the 7800, they just plopped one of those on the motherboard. Ah right. Well I have just notice that on playing 7800 games I get a bit of banding on that. It's only slight and hardly noticeable but it's there. So I am wondering if there is something wrong with the rf modulator. Also when I had the case open I noticed two silver discs that look like they could be twisted. Could they have anything to do with it because upon reading about the s-video mod (which I am thinking of doing or finding someone in the UK that would do it) you are supposed to twist and turn them to tune it in of sorts. Could possibly be the RF modulator I guess, although you'd need a second one to compare. I've never opened my 7800 and not as much of a hardware guy as I'd like to be so can't give an opinion on the silver disc thing. Quote Link to comment Share on other sites More sharing options...
Mayhem Posted October 18, 2009 Share Posted October 18, 2009 I've never seen a good RF modulator in a 7800 (especially PAL) so don't worry about that. Partly why I prefer to play on my NTSC S-video modded 7800 instead. Quote Link to comment Share on other sites More sharing options...
critanime Posted October 18, 2009 Author Share Posted October 18, 2009 I've never seen a good RF modulator in a 7800 (especially PAL) so don't worry about that. Partly why I prefer to play on my NTSC S-video modded 7800 instead. I just noticed today that I don't have a stitch next to my rf modulator. Will that have anything to do with it? Also would it help any if I did decide to try and retune the rf modulator. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted October 19, 2009 Share Posted October 19, 2009 The fact that the 7800 games display OK kind of rules out the RF modulator. With Haunted House having other issues besides graphical glitches really points to the TIA chip. Unfortunately, it's probably soldered to the motherboard and if you don't have a decent amount of soldering experience it might be difficult to remove with destroying the board. Mitch Quote Link to comment Share on other sites More sharing options...
critanime Posted October 19, 2009 Author Share Posted October 19, 2009 The fact that the 7800 games display OK kind of rules out the RF modulator. With Haunted House having other issues besides graphical glitches really points to the TIA chip. Unfortunately, it's probably soldered to the motherboard and if you don't have a decent amount of soldering experience it might be difficult to remove with destroying the board. Mitch Thanks for the reply Mitch. To be honest I am thinking of plugging my 2600 back in to play and just keep the 7800 for it's own games. The banding is not that bad and is something I just will ignore after a while. It's only really noticeable on commando on the start screen. Where a few pixels shimmy left then right randomly yet in the game it's not noticeable again. I am really enjoying playing the system now and may favourite two games have to be ms packman and ballblazer. If it completely dies in the future then I will just get another one. They aren't exactly expensive to get and as I mentioned earlier I got mine for £40 with 10 boxed games. Which I still think is a really good deal. Quote Link to comment Share on other sites More sharing options...
Gorf Posted October 19, 2009 Share Posted October 19, 2009 If it completely dies in the future then I will just get another one. They aren't exactly expensive to get and as I mentioned earlier I got mine for £40 with 10 boxed games. Which I still think is a really good deal. As Far as the RF goes, if your 7800 is like mine the cable is seperate from the unit...ie you plug it into an RCA on the unit, then to the RF modulator. Try changing that out with anew cable. I've used a monster video cable with good results as well. Quote Link to comment Share on other sites More sharing options...
critanime Posted October 19, 2009 Author Share Posted October 19, 2009 If it completely dies in the future then I will just get another one. They aren't exactly expensive to get and as I mentioned earlier I got mine for £40 with 10 boxed games. Which I still think is a really good deal. As Far as the RF goes, if your 7800 is like mine the cable is seperate from the unit...ie you plug it into an RCA on the unit, then to the RF modulator. Try changing that out with anew cable. I've used a monster video cable with good results as well. Monster video cable? Whats one of those? In any case as long as my 7800 can be cleaned up a little I ain't bothered about the 2600 compatibility because I have just bought a 2600 Jr off flebay for £30 with 4 games. So my 7800 is going to be used purely for 7800 games. After all there were some amazing games for it. Quote Link to comment Share on other sites More sharing options...
The_Laird Posted October 19, 2009 Share Posted October 19, 2009 If it completely dies in the future then I will just get another one. They aren't exactly expensive to get and as I mentioned earlier I got mine for £40 with 10 boxed games. Which I still think is a really good deal. As Far as the RF goes, if your 7800 is like mine the cable is seperate from the unit...ie you plug it into an RCA on the unit, then to the RF modulator. Try changing that out with anew cable. I've used a monster video cable with good results as well. Monster video cable? Whats one of those? In any case as long as my 7800 can be cleaned up a little I ain't bothered about the 2600 compatibility because I have just bought a 2600 Jr off flebay for £30 with 4 games. So my 7800 is going to be used purely for 7800 games. After all there were some amazing games for it. Its ok he is in the US I assume by your talk you are in the UK, you really should set your location it helps as NTSC 7800's are different from Pal ones and this would have helped with your probelem. I have had loads of trouble with the RF on my 7800 and the only simple fix is to leave your 7800 on for about 20 minutes before playing a game and then retune the TV (trust me it works and you get a better picture). I actually demonstrated this to several people at JFUK last month, maybe you can make next years show? Quote Link to comment Share on other sites More sharing options...
critanime Posted October 20, 2009 Author Share Posted October 20, 2009 Its ok he is in the US I assume by your talk you are in the UK, you really should set your location it helps as NTSC 7800's are different from Pal ones and this would have helped with your probelem. I have had loads of trouble with the RF on my 7800 and the only simple fix is to leave your 7800 on for about 20 minutes before playing a game and then retune the TV (trust me it works and you get a better picture). I actually demonstrated this to several people at JFUK last month, maybe you can make next years show? Yeah sorry I thought I did put on somewhere that I was from the uk and it was a pal system. Woops So do you mean leave it switched on for 20mins? Is this a once a day thing or will I have to do this with every game? To be honest the banding is only slight and since I plugged the 7800 into my 32inch tv I no longer get the 10 - 20 seconds of black and white now. I think the old sets I were using don't have as good a tuner as what the 32inch lcd does. Also where is JFUK held and whats it all about I did own a jaguar once upon a time but the evil ex has it now along with the cd drive Quote Link to comment Share on other sites More sharing options...
The_Laird Posted October 20, 2009 Share Posted October 20, 2009 (edited) I leave mine on for 20 minutes everytime before I play a game. The RF modulator changes its signal slighty when it comes on and so this is why I leave it to make sure it sorts its self out. Once you have done the retune after 20 minutes (can be less but best to leave it longer) it should go to the same signal everytime you turn it on as long as you leave it for the 20 minutes (on the retuned channel it will be fuzzy at first) JFUK is not just a Jaguar show (it started as one) now its a pure retro gaming show with a focus on Atari. At the last show we had PC Engine, Wonderswan, Dreamcast, SNES, 7800, Falcon, ST, N64 and 5200 all present. The last show was in Luton (its been around a bit) and was hosted by myself, next year will most likely be the same location as it seemed to suit everyone Edited October 20, 2009 by The_Laird Quote Link to comment Share on other sites More sharing options...
critanime Posted October 20, 2009 Author Share Posted October 20, 2009 I leave mine on for 20 minutes everytime before I play a game. The RF modulator changes its signal slighty when it comes on and so this is why I leave it to make sure it sorts its self out. Once you have done the retune after 20 minutes (can be less but best to leave it longer) it should go to the same signal everytime you turn it on as long as you leave it for the 20 minutes (on the retuned channel it will be fuzzy at first) JFUK is not just a Jaguar show (it started as one) now its a pure retro gaming show with a focus on Atari. At the last show we had PC Engine, Wonderswan, Dreamcast, SNES, 7800, Falcon, ST, N64 and 5200 all present. The last show was in Luton (its been around a bit) and was hosted by myself, next year will most likely be the same location as it seemed to suit everyone That con sounds pretty sweet and would be right up my ally. I love my retro stuff especially my atari's but I will be honest my first love is the c64. Will try that trick now with the 7800 see if it works. Quote Link to comment Share on other sites More sharing options...
critanime Posted November 14, 2009 Author Share Posted November 14, 2009 Will try that trick now with the 7800 see if it works. I gave up on that 7800. It plays games and I can see clearly whats happening but the games still have strange sprite behaviour and it's doing my tree in. So.... In comes 7800 number 2. Just got it from ebay today and hopefully this one now works perfectly. Gonna test it at work and see what happens. Dunno what I am gonna do with the old one. It works and all but not perfectly. Dunno if I should sell it on as not perfect and see if I can find someone who would fix it up. Or buy it for spares. Quote Link to comment Share on other sites More sharing options...
nonner242 Posted November 14, 2009 Share Posted November 14, 2009 Does it work? Quote Link to comment Share on other sites More sharing options...
critanime Posted November 14, 2009 Author Share Posted November 14, 2009 Does it work? Yes. However i have not tried commando or haunted house on it. They were the ones causing issues. Does anyone know if the s video mod works right on the pal version? Quote Link to comment Share on other sites More sharing options...
mimo Posted November 14, 2009 Share Posted November 14, 2009 S-video mod does work on PAL, but some LCD/Plasma TV's can be picky about the signal. Best option is to try and find a French 2600, they have RGB Scart output as standard, I think there was someone selling one, oh yes it was Lucifershalo, he sent me a PM Quote Link to comment Share on other sites More sharing options...
+Mitch Posted November 14, 2009 Share Posted November 14, 2009 S-video mod does work on PAL, but some LCD/Plasma TV's can be picky about the signal. Best option is to try and find a French 2600, they have RGB Scart output as standard, I think there was someone selling one, oh yes it was Lucifershalo, he sent me a PM I think you mean French 7800 not 2600. Mitch Quote Link to comment Share on other sites More sharing options...
critanime Posted November 14, 2009 Author Share Posted November 14, 2009 lol i did think it sounded a little odd. Besides the thing works and i am happy again. Lol. Still same graphical glitches on commando. So it's either a system flaw or a game flaw. Either way it's all good. Quote Link to comment Share on other sites More sharing options...
mimo Posted November 14, 2009 Share Posted November 14, 2009 S-video mod does work on PAL, but some LCD/Plasma TV's can be picky about the signal. Best option is to try and find a French 2600, they have RGB Scart output as standard, I think there was someone selling one, oh yes it was Lucifershalo, he sent me a PM I think you mean French 7800 not 2600. Mitch doh! Quote Link to comment Share on other sites More sharing options...
DEANJIMMY Posted November 22, 2009 Share Posted November 22, 2009 S-video mod does work on PAL, but some LCD/Plasma TV's can be picky about the signal. Best option is to try and find a French 2600, they have RGB Scart output as standard, I think there was someone selling one, oh yes it was Lucifershalo, he sent me a PM I think you mean French 7800 not 2600. Mitch doh! I have such a scart console but like to play with the PAL RF version. The picture does not get so much more stable. If you open the case of the 7800 and remove the shielding, you will find two pots. One adjusts the colors for 7800 games an the other for 2600 games. The pot for 7800 games is adjustable without removing the shielding from the top below the connector for the cartridge. The one for 2600 games can be found if you look at the bottom side of the circuit board once you removed the shielding. You can actually adjust it without removing the shielding by lifting up the circuit board but you won't probably find the pot without removing the shielding. If the pot is far out of range you will not just get wrong colors but a bad picture. Commando, Xevious and Impossible Mission give you quite a flickering picture. On a LCD TV it helps to put DNR settings to max and use 4:3 format rather than auto, 16:9, 14:9 what ever. After I adjusted the pot for 2600 games, the 7800 gives me the 2nd best picture for such games (best ist still 6er 2600 wood grain). There should be some post here or on the net to show the location of the two pots. Quote Link to comment Share on other sites More sharing options...
gdement Posted November 24, 2009 Share Posted November 24, 2009 If the PAL version is anything like the NTSC version, then there's some tradeoff between the 2600 and 7800 color adjustments. If you're only going to use your 7800 for 7800 games, and you don't care about the image quality with 2600, then you might get a better picture by turning the 2600 color pot to max impedance (essentially shutting it off). There's some interference between the 2600 and 7800 color circuits, and those knobs are used to control the tradeoff between the signal strength of each. So blocking off the 2600 signal might help a bit with the 7800 image. I've never tried doing this though, so I have no idea how much difference it would make. Quote Link to comment Share on other sites More sharing options...
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