HunterZero Posted January 15, 2013 Share Posted January 15, 2013 Hello all! First post. I have an Australian 50Hz Intellivision here with weird logic problems (it has a daughterboard over one end), was wondering if anyone could point towards what the problem could be. Started out completely dead. Fixed this by reflowing cracked solder on the 2 pin power header, and replacing the ribbon connector entirely (it had come apart completely and the two outside wires were bad). Tested voltages, seems OK, but not sure what result I should get on the pin from the capacitor? However the console then booted to a black screen. I remembered when I put it into storage years ago that the sound would start to go bad as the console heated up, eg the arrow count sound on AD&D would be missing. Desoldering the shielding was a complete pig... I replaced the sound chip with a known working one, and now the console boots to the title screen, yay! However, now the console tends to crash. I tried a few games: * AD&D Cloudy Mountain starts and you can select difficulty and move about the map, but crashes to olive screen when you try to enter a mountain * Burger Time starts and plays, but crashes to black screen when you lose a life (death animation doesn't play) or complete a level. * Demon Attack plays, but the aliens have sprite problems (missing red bodies and just appear as eyes) and the player's ship glitches about when you move * Pole Position plays fine! All carts tested working fine on another system. So I'm wondering if this is some sort of exec ROM, RAM or STIC issue? I have quite a few other games and Intellivoice with it, so could try a few more if you could suggest them to get more symptoms. - James Quote Link to comment Share on other sites More sharing options...
+DZ-Jay Posted January 15, 2013 Share Posted January 15, 2013 Hmm... Sprite problems in some games, crashes in others, and still others play fine... To me that sounds like a problem reading ROM (cartridge). I do not know much about the hardware, so I'd wait for the experts to chime in and offer information. -dZ. Quote Link to comment Share on other sites More sharing options...
LidLikesIntellivision Posted January 15, 2013 Share Posted January 15, 2013 I have similar problems with my Colecovision. When I looked at my slot cartridge Some connectors were twisted and at least one missing. I'm still waiting to send my system to a tech guy... Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 15, 2013 Author Share Posted January 15, 2013 (edited) I'm wondering if it's the exec ROM because there are apparently library routines in there that may be used by some games and bypassed by others, but don't know enough about how some games use the exec to be sure. I will give it another clean though. The games consistently have the exact same problems. - James Edited January 15, 2013 by HunterZero Quote Link to comment Share on other sites More sharing options...
+DZ-Jay Posted January 15, 2013 Share Posted January 15, 2013 I'm wondering if it's the exec ROM because there are apparently library routines in there that may be used by some games and bypassed by others, but don't know enough about how some games use the exec to be sure. I will give it another clean though. The games consistently have the exact same problems. - James It could be the EXEC, but most games have the EXEC load the graphics for them too. If that part is failing in one game, it would fail in most others, no? dZ. Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 15, 2013 Author Share Posted January 15, 2013 If the exec had failed entirely, yes - but I'm wondering if it's possible that only part of the ROM in the exec has gone bad, so only a subset of the routines in the exec cause problems. - James Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 17, 2013 Author Share Posted January 17, 2013 (edited) Rechecked voltages... + 5 VDC --+ | |_| | Checks OK + 12 VDC --+ | |_| | Checks OK + 16 VDC --+ | |_| | Reads 23.3V DC steady... Unregulated + 0 VDC --+ | |_| | Checks OK - 2 VDC --+ |_|_|_| Checks OK Bear in mind this is a 240V PAL unit, so I am not sure if that high reading on the unregulated third pin is OK or not, or if I should look to replace the 2200uF capacitor? Cleaned and reseated all chips and the cartridge port with DeOxit... No improvement. - James Edited January 17, 2013 by HunterZero Quote Link to comment Share on other sites More sharing options...
ebelhaki Posted January 18, 2013 Share Posted January 18, 2013 Rechecked voltages... + 5 VDC --+ | |_| | Checks OK + 12 VDC --+ | |_| | Checks OK + 16 VDC --+ | |_| | Reads 23.3V DC steady... Unregulated + 0 VDC --+ | |_| | Checks OK - 2 VDC --+ |_|_|_| Checks OK Bear in mind this is a 240V PAL unit, so I am not sure if that high reading on the unregulated third pin is OK or not, or if I should look to replace the 2200uF capacitor? Cleaned and reseated all chips and the cartridge port with DeOxit... No improvement. - James My super video arcade has those exact same voltages and it works fine. Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 18, 2013 Author Share Posted January 18, 2013 Thanks for that. So the next thing would be suggestions for cartridges to try to get more symptoms... Unless someone has a test cartridge they can lend me? - James Quote Link to comment Share on other sites More sharing options...
pimpmaul69 Posted January 24, 2013 Share Posted January 24, 2013 Hmm... Sprite problems in some games, crashes in others, and still others play fine... To me that sounds like a problem reading ROM (cartridge). I do not know much about the hardware, so I'd wait for the experts to chime in and offer information. -dZ. since intvnut is lost in voltrons dimension you might have an answer for this guys dilema. do some games load one area into a ram chip but another into another ram chip dividing the levels? (ie: going through a door runs info stored on another ram chip?) maybe in demon attacks case, loading different parts into different ram chips. i am not a software guy so i am unsure of this. Quote Link to comment Share on other sites More sharing options...
+DZ-Jay Posted January 24, 2013 Share Posted January 24, 2013 (edited) since intvnut is lost in voltrons dimension you might have an answer for this guys dilema. do some games load one area into a ram chip but another into another ram chip dividing the levels? (ie: going through a door runs info stored on another ram chip?) maybe in demon attacks case, loading different parts into different ram chips. i am not a software guy so i am unsure of this. I'm not an expert in such things, but I would imagine that the RAM chips are abstracted to the software. That is, the software only references RAM by it's address, irrespective (and unknowing) of where it resides physically. However, I don't think it's to do with RAM, inasmuch as graphics and level data is typically stored in the cartridge ROM and read directly from there. RAM is only used for dynamically changing game state. If a RAM chip were bad, I would imagine you would see all games failing (I can't imagine a game not using most of its RAM for something, since that was one of the constraints). That's why I pointed to the ROM port or something to do with the reading of the cartridge ROM: to me it sounds like some parts of the ROM are being corrupted when read in. Any particular address segment of the ROM space would contain different things for each game (graphics, game logic, etc.), resulting on the failure manifesting differently. But again, this is just wild speculation. I honestly do not know much about the internal hardware to help. -dZ. Edited January 24, 2013 by DZ-Jay Quote Link to comment Share on other sites More sharing options...
pimpmaul69 Posted January 24, 2013 Share Posted January 24, 2013 I'm not an expert in such things, but I would imagine that the RAM chips are abstracted to the software. That is, the software only references RAM by it's address, irrespective (and unknowing) of where it resides physically. However, I don't think it's to do with RAM, inasmuch as graphics and level data is typically stored in the cartridge ROM and read directly from there. RAM is only used for dynamically changing game state. If a RAM chip were bad, I would imagine you would see all games failing (I can't imagine a game not using most of its RAM for something, since that was one of the constraints). That's why I pointed to the ROM port or something to do with the reading of the cartridge ROM: to me it sounds like some parts of the ROM are being corrupted when read in. Any particular address segment of the ROM space would contain different things for each game (graphics, game logic, etc.), resulting on the failure manifesting differently. But again, this is just wild speculation. I honestly do not know much about the internal hardware to help. -dZ. alrighty, good to know. so that helps narrow his issue down. he was supposed to send me pics of the board but that has not happened yet, so now i know where to look for the possible damage. so between the cart slot and the exec and possibly anything between the 2. and a faulty exec could be tested with a can of air to freeze it and see if it keeps running if heat is a factor. Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 25, 2013 Author Share Posted January 25, 2013 Hi all, thanks for the replies. I haven't had a chance yet to tear down the unit again to take photos. I'll try and do that as soon as I can. Is there an area I should concentrate on for more detailed photos? I'll take detail photos of the traces and parts around the exec and cartridge slot. I did tidy up all the soldered ground traces around the cartridge slot after removing the huge blob of solder there that was holding on the shielding. Would it be a heat related issue if the console has the same crashes immediately after being turned on from cold? - James Quote Link to comment Share on other sites More sharing options...
pimpmaul69 Posted January 25, 2013 Share Posted January 25, 2013 Hi all, thanks for the replies. I haven't had a chance yet to tear down the unit again to take photos. I'll try and do that as soon as I can. Is there an area I should concentrate on for more detailed photos? I'll take detail photos of the traces and parts around the exec and cartridge slot. I did tidy up all the soldered ground traces around the cartridge slot after removing the huge blob of solder there that was holding on the shielding. Would it be a heat related issue if the console has the same crashes immediately after being turned on from cold? - James probably not Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 28, 2013 Author Share Posted January 28, 2013 As requested, some pics attached. - James Quote Link to comment Share on other sites More sharing options...
pimpmaul69 Posted January 28, 2013 Share Posted January 28, 2013 As requested, some pics attached. - James what is up with the blue capacitor next to the channel switch. does not look right. Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 29, 2013 Author Share Posted January 29, 2013 (edited) what is up with the blue capacitor next to the channel switch. does not look right. It looks like the heatshrink has shrunk and split on that capacitor (is that C31?). The capacitor cylinder itself doesn't look like it is bulging or anything. I thought the plastic may have just shrunk as the plastic deteriorated with age or use with the heat in the console, but now you mention it the capacitor may have been the cause of the heat and failed/overheated. May as well try replacing it, I'll see if it makes a difference. Other than that, there's only some very light discolouration underneath the two transistors that you can see on the bottom of the board. Two of the crashes do seem to be just before the game plays a louder volume sound, ie the swoosh on AD&D and the loss of life music on BurgerTime. - James Edited January 29, 2013 by HunterZero Quote Link to comment Share on other sites More sharing options...
pimpmaul69 Posted January 29, 2013 Share Posted January 29, 2013 It looks like the heatshrink has shrunk and split on that capacitor (is that C31?). The capacitor cylinder itself doesn't look like it is bulging or anything. I thought the plastic may have just shrunk as the plastic deteriorated with age or use with the heat in the console, but now you mention it the capacitor may have been the cause of the heat and failed/overheated. May as well try replacing it, I'll see if it makes a difference. Other than that, there's only some very light discolouration underneath the two transistors that you can see on the bottom of the board. Two of the crashes do seem to be just before the game plays a louder volume sound, ie the swoosh on AD&D and the loss of life music on BurgerTime. - James replace both. They both can cause problems and are cheap Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 29, 2013 Author Share Posted January 29, 2013 (edited) replace both. They both can cause problems and are cheap So replace both the blue cap near the channel switch, and both transistors? - James Edited January 29, 2013 by HunterZero Quote Link to comment Share on other sites More sharing options...
pimpmaul69 Posted January 29, 2013 Share Posted January 29, 2013 So replace both the blue cap near the channel switch, and both transistors? - James yup Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 29, 2013 Author Share Posted January 29, 2013 (edited) yup What specifications are those two transistors? They are only shown as NPN? (Is Q2 PNP?) on the schematic. Will this do? http://www.jaycar.co...w.asp?ID=ZT2283 - James Edited January 29, 2013 by HunterZero Quote Link to comment Share on other sites More sharing options...
pimpmaul69 Posted January 29, 2013 Share Posted January 29, 2013 (edited) What specifications are those two transistors? They are only shown as NPN on the schematic. Will this do? Is Q2 PNP? http://www.jaycar.co...w.asp?ID=ZT2283 - James there are part numbers on them and is a very common part. But yeah npn transistors arent that picky. If they are pnp do not use npn Edited January 29, 2013 by pimpmaul69 Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 29, 2013 Author Share Posted January 29, 2013 (edited) Given their proximity to the CPU and the crashing nature of the fault, I'm inclined to agree and suspect those transistors... Found a better schematic that lists them both as 2N3906 PNP Transistor. http://intellivision_2609.tripod.com/2609_schematic.JPG http://www.jaycar.com.au/productView.asp?ID=ZT2328 - James Edited January 29, 2013 by HunterZero Quote Link to comment Share on other sites More sharing options...
pimpmaul69 Posted January 29, 2013 Share Posted January 29, 2013 Given their proximity to the CPU and the crashing nature of the fault, I'm inclined to agree and suspect those transistors... Found a better schematic that lists them both as 2N3906 PNP Transistor. http://intellivision...9_schematic.JPG http://www.jaycar.co...w.asp?ID=ZT2328 - James in the pics you cannot see the burning as in the case of most of them with bad transistors Quote Link to comment Share on other sites More sharing options...
HunterZero Posted January 29, 2013 Author Share Posted January 29, 2013 in the pics you cannot see the burning as in the case of most of them with bad transistors Although it's faint, you can actually see brown discolouration of the board under those two transistors. It is faint, I didn't notice it until I took the pictures. I'll pick up a replacement for that cap and transistors and see how that goes. - James Quote Link to comment Share on other sites More sharing options...
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