dafivehole Posted May 19, 2010 Share Posted May 19, 2010 From reading some other posts, I am thinking that the red screen means dead RAM? With this in mind, I am assuming that no one would want this for anything other than spare parts? Just curious but my CAPS key on my 800XL is broken, could I swap keyboards with the 600XL (are they exactly the same)? Thanks, Roger Quote Link to comment Share on other sites More sharing options...
Rybags Posted May 19, 2010 Share Posted May 19, 2010 It might mean dead RAM. You can get the same thing if you pull out Antic, the OS ROM, and probably several other ways. Not worth scrapping the system unless the motherboard is borked. Everything on it is reasonably easy to source and replace, and you can upgrade to 64K fairly easily. Some keyboards have a ribbon that goes straight to the motherboard, others have an intermediate header that plugs into the motherboard with a row of resistors on it. Not sure about the interchangability of them - I assume you could just add or remove the intermediate header. There was an entire thread a few years back that described the several varieties of XL keyboards and their differences. Quote Link to comment Share on other sites More sharing options...
dafivehole Posted May 19, 2010 Author Share Posted May 19, 2010 Both of my keyboards have the mylar ribbon that goes right into the MB. After taking the shield off, there are a ton of chips in there... I'm not sure which is which Roger Quote Link to comment Share on other sites More sharing options...
Rybags Posted May 19, 2010 Share Posted May 19, 2010 (edited) 600XL is reasonably simple - all the chips should be socketed. OS and Basic ROM are at the top right. CPU, Antic, GTIA and PIA are the 40-pin chips nearer the bottom, you can ID them by looking up their COxxxxxx numbers. Most of the small chips in the middle under the cart slot are generic logic ICs that can be replaced by off-the-shelf 74LS series ICs, most of them are involved in the memory selection logic. The RAM ICs should be 2 chips with 4416 in their names. You can replace them with 4464 chips and the system can use the lower 16K of each - to get a full 64K upgrade you need to do the mod to add the extra RAS/CAS line. First step in diag/fixing a problem with XLs should be to slightly lift up then reseat the chips. They tend to get a light oxide coating on the legs which might lead to the system stopping working. If that doesn't fix it, then there's the chance that something has been fried, often due to bad PSUs that go overvolt. All this stuff is a lot easier to diagnose if you've got a known good system that you can just swap stuff over to test in. Edited May 19, 2010 by Rybags Quote Link to comment Share on other sites More sharing options...
dafivehole Posted May 19, 2010 Author Share Posted May 19, 2010 (edited) Upon closer inspection, one of the RAM chips wasn't all the way seated... needless to say, I was pretty excited at the notion that this was the problem. I pulled it out (that sounded weird) and reseated it... I checked all of the other chips and they looked good. After re-assembling everything and turning it back on... the screen is now black (instead of red) Roger Edited May 19, 2010 by dafivehole Quote Link to comment Share on other sites More sharing options...
Rybags Posted May 19, 2010 Share Posted May 19, 2010 Maybe try the OS ROM - the bigger of the 2 ICs in top right. If you're not experienced or don't have the proper IC puller tool, the best method is to gently lever between the socket and IC with a small flatblade precision screwdriver. You only need to pull the chip up 1 mm or so, then push it back in. Then try powering on with and without holding down OPTION. Also try a game cartridge or two if you've got some. Quote Link to comment Share on other sites More sharing options...
dafivehole Posted May 19, 2010 Author Share Posted May 19, 2010 I'm out of time right now, so when I get home from work (tomorrow morning), I'll try that with the OS ROM and report my findings. I appreciate your assistance with this... Later, Roger Quote Link to comment Share on other sites More sharing options...
Rybags Posted May 20, 2010 Share Posted May 20, 2010 The 800XL Field Service Manual should be buried somewhere in the thread in my tagline. If you've got an oscilloscope, diagnosing can be made easier - you can check certain points for signs of life. But the fact that you've gone from a "red" to "black" probably suggests that at least the CPU should be OK. Quote Link to comment Share on other sites More sharing options...
Defender II Posted May 20, 2010 Share Posted May 20, 2010 Definitely a keeper. Easy to fix. Try re-seating them again. I just had a red screen caused by bad RAM. I'm looking for 8-64K chips for it right now. Do you have another 600XL or extra RAM? If your 800XL chips are socketed you can try swapping the lager chips. Just take your time and make sure all of the pins go into the socket holes. Don't get in a rush between swapping chips and forget to power down & unplug in between. If you need a POKEY chip I have some. Good luck. Quote Link to comment Share on other sites More sharing options...
Defender II Posted May 20, 2010 Share Posted May 20, 2010 Some of the keyboards are swappable, it depends on the 800XL case. How is the key broken? If you do decide you don't want it let me know. Quote Link to comment Share on other sites More sharing options...
Rybags Posted May 20, 2010 Share Posted May 20, 2010 Note though that the RAM isn't interchangable between 800XL/600XL. Quote Link to comment Share on other sites More sharing options...
dafivehole Posted May 20, 2010 Author Share Posted May 20, 2010 OK guys... reseated the OS and RAM chips and still nothing... any more ideas? I don't have a lot to steal parts from for testing purposes... I'd rather not mess with my 800XL. Roger Quote Link to comment Share on other sites More sharing options...
Rybags Posted May 20, 2010 Share Posted May 20, 2010 (edited) If you've got an oscilloscope, you can test certain points for signs of life. Otherwise, about all I can think of at this stage is trying one at a time - the OS, MMU, Antic, and CPU from the 600XL in the 800XL to see if any of those are bad. After that, it might come down to checking the 74LS chips that are common to both. If it is the case that everything checks out OK, then it's probably a motherboard fault. Might be something as simple as a severed trace or solder joint gone bad. Checking continuity would be a bit of drawn out process... e.g. address and data bus have multiple connections per line, so it runs into the hundreds of checks, although someone experienced at it could probably do near 100 a minute. Edited May 20, 2010 by Rybags Quote Link to comment Share on other sites More sharing options...
dafivehole Posted May 20, 2010 Author Share Posted May 20, 2010 Wow, most of that sounds like it's over my head... I'll go ahead and seal her up and see if anyone is interested with it the way it is... I appreciate your help on this one. Thanks, Roger Quote Link to comment Share on other sites More sharing options...
atariksi Posted May 20, 2010 Share Posted May 20, 2010 Wow, most of that sounds like it's over my head... I'll go ahead and seal her up and see if anyone is interested with it the way it is... I appreciate your help on this one. Thanks, Roger If you want to swap, I can send you a 800XL that's working except option key... Pmail me. Quote Link to comment Share on other sites More sharing options...
+orpheuswaking Posted May 20, 2010 Share Posted May 20, 2010 (edited) From reading some other posts, I am thinking that the red screen means dead RAM? With this in mind, I am assuming that no one would want this for anything other than spare parts? Just curious but my CAPS key on my 800XL is broken, could I swap keyboards with the 600XL (are they exactly the same)? Thanks, Roger How is the CAPS key broken? I have a donor machine that has a good keyboard on it that I could pull the CAPS key from (or is it just not working when you press it, that could be a mylar issue)... There are several types of keyboards and I know that I have had clearance issues in the 600XL when putting some of them from an 800XL into a 600XL, however I don't "think" you will have issues going the other way. As for the 600xl, I have several that are all upgraded to 64k, I would be willing to swap your dead one for one of those, that way I can swap parts in and out and figure out whats wrong and you get a working machine with 64k... Let me know... Also I see in your SIG that you are looking for 800xl items. anything in particular? Shoot me a PM, I have a basement full of stuff for trade/sale (In the middle of inventory right now LOL) Edited May 20, 2010 by orpheuswaking Quote Link to comment Share on other sites More sharing options...
+Guitarman Posted May 21, 2010 Share Posted May 21, 2010 I have a basement full of stuff for trade/sale (In the middle of inventory right now LOL) LOL!!! You sound like me!! Quote Link to comment Share on other sites More sharing options...
+orpheuswaking Posted May 21, 2010 Share Posted May 21, 2010 I have a basement full of stuff for trade/sale (In the middle of inventory right now LOL) LOL!!! You sound like me!! Well the 1040 STe down there you sold me I'm exaggerating slightly, most of the stuff is NOT for sale as it's part of the collection. but when I'm done with inventory I'll have stuff to let go (need to fund more collection)... and I know there is no way my basement looks like yours, you saved some awesome collections man... (hopefully dafivehole doesn't mind me jacking his thread... this photo is pre inventory - as I was getting stuff ready - it's about half of the collection, the rest is upstairs in my bedroom and includes my Jaguar collection) Quote Link to comment Share on other sites More sharing options...
+David_P Posted May 21, 2010 Share Posted May 21, 2010 Well the 1040 STe down there you sold me I'm exaggerating slightly, most of the stuff is NOT for sale as it's part of the collection. but when I'm done with inventory I'll have stuff to let go (need to fund more collection)... and I know there is no way my basement looks like yours, you saved some awesome collections man... (hopefully dafivehole doesn't mind me jacking his thread... this photo is pre inventory - as I was getting stuff ready - it's about half of the collection, the rest is upstairs in my bedroom and includes my Jaguar collection) You are my new hero. From now on, whenever my wife looks at my collection, I'll just pull up that photo and say "I've still got a ways to go yet, dear..." Quote Link to comment Share on other sites More sharing options...
tjlazer Posted May 23, 2010 Share Posted May 23, 2010 I have a basement full of stuff for trade/sale (In the middle of inventory right now LOL) LOL!!! You sound like me!! Well the 1040 STe down there you sold me I'm exaggerating slightly, most of the stuff is NOT for sale as it's part of the collection. but when I'm done with inventory I'll have stuff to let go (need to fund more collection)... and I know there is no way my basement looks like yours, you saved some awesome collections man... (hopefully dafivehole doesn't mind me jacking his thread... this photo is pre inventory - as I was getting stuff ready - it's about half of the collection, the rest is upstairs in my bedroom and includes my Jaguar collection) Wow wish mine was as neat and organized as yours! A basement would be nice too... lol Quote Link to comment Share on other sites More sharing options...
+Guitarman Posted May 24, 2010 Share Posted May 24, 2010 Well the 1040 STe down there you sold me I'm exaggerating slightly, most of the stuff is NOT for sale as it's part of the collection. but when I'm done with inventory I'll have stuff to let go (need to fund more collection)... and I know there is no way my basement looks like yours, you saved some awesome collections man... (hopefully dafivehole doesn't mind me jacking his thread... this photo is pre inventory - as I was getting stuff ready - it's about half of the collection, the rest is upstairs in my bedroom and includes my Jaguar collection) This is the start of what I set up in the garage when I recently moved. I'll be organizing the rest of it and post pics in my blog soon. You can see the fruits from my visit to Target last year from the last pic. Quote Link to comment Share on other sites More sharing options...
Havok69 Posted May 24, 2010 Share Posted May 24, 2010 This is the start of what I set up in the garage when I recently moved. I'll be organizing the rest of it and post pics in my blog soon. You can see the fruits from my visit to Target last year from the last pic. I hope you got a clearance price on those! (I got mine for $9!!!) Quote Link to comment Share on other sites More sharing options...
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