gobo Posted March 19, 2021 Share Posted March 19, 2021 Hi I bought a good looking 600Xl off of ebay months ago on a whim (never had a 600xl). It came with a 64K upgrade and an S-Video upgrade. I finally got around to trying it and it's dead as a door-nail. The power supply tested at steady 5.1v that works on another 800xl . I also tried a modern USB PS as well that works on the 800xl. The 600xl's LED stays off when powered on, nothing on the screen, no sound. I've never worked on fixing an Atari on the hardware side and I don't know what I'm doing overall but I did use a multi-meter on all of the chips and they are all getting about 4.2 volts. Should it still be 5v by the time it gets to the chips or is that normal? I re-seated the chips and that did nothing. Not sure if the upgrades have anything to do with it either but it was sold as tested and working. None of the chips get very hot to touch. The motherboard itself looks clean other than the spaghetti. I've attached some pics but not sure that will help. The voltage is even 4.2 at the SIO port and the keyboard cable that supposedly powers the LED. Is that low enough to keep it from even turning on? Quote Link to comment Share on other sites More sharing options...
Paul Westphal Posted March 19, 2021 Share Posted March 19, 2021 (edited) No offence, but what a mess! It looks like it has the oldskool stereo mod - I see the stacked Pokey's and the RCA's out. I also see the jumper to the CPU for it. Not sure why they removed the Basic A chip ( top left ).. B doesn't look custom.. I have seen many bad PIA's lately, but it could be anything. 4050.. any of the main chips.. This is my 64k upgrade : Edited March 19, 2021 by Paul Westphal Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted March 19, 2021 Share Posted March 19, 2021 (edited) Your power supply is too low, 4 volts is not going to cut it. Your 6520 has a pin out of it's socket (maybe to support the mod) and you have a missing chip. There are pictures and schematics strew all about the AA forums showing what chips belong where and what's acceptable Edited March 19, 2021 by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
Paul Westphal Posted March 19, 2021 Share Posted March 19, 2021 Here ya go : https://www.8bitclassics.com/product/atari-xl-xe-power-supply/ Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted March 19, 2021 Share Posted March 19, 2021 (edited) the rf out connector and the added rca jack next to it are the right and left stereo out. un-insulated wire need attention or you may end up with another damaged machine or power supply a video out is the jack next to the cartridge port. Edited March 19, 2021 by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
gilsaluki Posted March 19, 2021 Share Posted March 19, 2021 Apocalypse Now (Colonel Kurt). "The Horror, the horror". 2 Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted March 19, 2021 Share Posted March 19, 2021 Where is the real RF output now? and why is the PIA pin lifted? Quote Link to comment Share on other sites More sharing options...
Paul Westphal Posted March 19, 2021 Share Posted March 19, 2021 (edited) The pia pin is lifted for the stereo mod as is the jumper to the CPU. Just buy a basic A then start from there. Best Electronics has them. I'm looking now. Rf out should still work - it has to Edited March 19, 2021 by Paul Westphal Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted March 19, 2021 Share Posted March 19, 2021 can you say it's and accident waiting to happen that actually did. Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted March 19, 2021 Share Posted March 19, 2021 don't buy a BASIC rev A... Buy a BASIC rev C 1 Quote Link to comment Share on other sites More sharing options...
Paul Westphal Posted March 19, 2021 Share Posted March 19, 2021 Yeah - what the doctor said.. I just refer to it as Basic A in the " O.S. " section. Version C basic is the way to go. Quote Link to comment Share on other sites More sharing options...
Paul Westphal Posted March 19, 2021 Share Posted March 19, 2021 Brad at Best Electronics has those, but you will have to be patient with him and set up an account. He has a $20 minimum as well. Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted March 19, 2021 Share Posted March 19, 2021 That really has to be the worst example of a bodge job ever, as @_The Doctor__ said it's an accident that's already happened 1 Quote Link to comment Share on other sites More sharing options...
BillC Posted March 19, 2021 Share Posted March 19, 2021 (edited) 1 hour ago, _The Doctor__ said: don't buy a BASIC rev A... Buy a BASIC rev C 1 hour ago, Paul Westphal said: Brad at Best Electronics has those, but you will have to be patient with him and set up an account. Best Electronics is SOLD OUT of the Rev.C BASIC IC, they still have the cartridge version for $20. The lack of BASIC is not the problem, there's no point in getting BASIC until the machine is otherwise working. This 600XL has the jumpers/IC socket footprint to choose between ROM/EPROM for BASIC, updating the BASIC socket to 28 pins and changing the 2 jumpers will allow use of a programmed 2764 EPROM instead of the original 24 pin ROM. Edited March 19, 2021 by BillC 5 Quote Link to comment Share on other sites More sharing options...
gobo Posted March 20, 2021 Author Share Posted March 20, 2021 No offence, but what a mess! Apocalypse Now (Colonel Kurt). "The Horror, the horror". Worst example of a bodge job ever Can you say it's and accident waiting to happen that actually did. LOL Guys, tell me what you REALLY think! ?? And she's such a beauty...on the outside! Maybe I should just rip it all out and go back to stock. Would almost feel bad undoing all that hard work! Weird thing is both power supplies are putting out 5v. The USB one is rated at 3 amps. Even the SIO port says 4.2v. Maybe that capacitor by the power switch? The 4.2v it seems to be system wide. Would it not even turn on without an BASIC chip? The back panel has an S-video and an audio jack. The RF jack is still there. It does look scary in there!! 1 Quote Link to comment Share on other sites More sharing options...
Paul Westphal Posted March 20, 2021 Share Posted March 20, 2021 Super glad you have a good sense of humor. People get uptight around here sometimes That IS a really nice 600XL! Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted March 20, 2021 Share Posted March 20, 2021 make sure none of the bodges are touching anything when case is open or closed... make sure none of the chips are HOT to the touch after it's been on a bit... make sure no lose piece of metal, wire trimmings, solder flakes or balls have worked their way under or across anything.. make sure nothing is touching a bottom side of the board shield if it still exists. any HOT chip may be shorted any bad cap near the power supply could also pull power lower... You are losing voltage because of an excess draw. You don't wanna be less than 4.75 anywhere normally... 1 Quote Link to comment Share on other sites More sharing options...
Sugarland Posted March 20, 2021 Share Posted March 20, 2021 How about moving the chips one at a time to a known good machine? Two pokeys are a nice bonus. Quote Link to comment Share on other sites More sharing options...
gobo Posted March 20, 2021 Author Share Posted March 20, 2021 Well there may be life in it yet. I switched out the keyboard and now the LED comes on. Guess even the keyboard was bad! This thing might turn into Princess Fiona next! Still nothing on screen, not even a blip when powered on with both S-Video or RF. The multi-meter says 5v at the power port input inside the XL and on the lower lead of the power switch when it's in the off position but when I turn it on the voltage drops to 4.2 on the power switch (lower and middle lead) and everywhere I check on the motherboard that should be 5v. I wonder why someone would go through the trouble of doing all that work in such a nice looking case. I guess I'm shallow because if it was ugly and beat up it would be easier to let it go! Next step is to get rid all of the upgrades. Quote Link to comment Share on other sites More sharing options...
Sugarland Posted March 20, 2021 Share Posted March 20, 2021 Could the low voltage be a mild short somewhere? Quote Link to comment Share on other sites More sharing options...
gobo Posted March 20, 2021 Author Share Posted March 20, 2021 Thanks Sugarland. I'm going to try both of those ideas. I'm new at troubleshooting electronic circuits and ICs so I appreciate all the help I get! Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted March 20, 2021 Share Posted March 20, 2021 10 hours ago, Paul Westphal said: This is my 64k upgrade Why the pick off points on the PBI contacts and the immensely heavy wire? 1 Quote Link to comment Share on other sites More sharing options...
leech Posted March 20, 2021 Share Posted March 20, 2021 11 hours ago, gilsaluki said: Apocalypse Now (Colonel Kurt). "The Horror, the horror". Every time I watch that movie, I think "I should quote this line more." I know there is a different system already called the Medusa, but this really is an Atari Medusa... Quote Link to comment Share on other sites More sharing options...
Sugarland Posted March 20, 2021 Share Posted March 20, 2021 After checking the IC's, I would seriously consider removing all that crap and put it back to stock. 1 Quote Link to comment Share on other sites More sharing options...
bfollowell Posted March 20, 2021 Share Posted March 20, 2021 11 hours ago, BillC said: Best Electronics is SOLD OUT of the Rev.C BASIC IC, they still have the cartridge version for $20. The lack of BASIC is not the problem, there's no point in getting BASIC until the machine is otherwise working. ^This Brad has been sold out of Basic Rev C for a while now. Marlin at The Brewing Academy sold me one that he'd made himself, along with the converter to make it fit my Basic socket. I can't remember exactly what it cost, but he's always reasonable and it's probably a better choice than trying to find one on ebay. While I agree that you definitely have other issues, you are still going to need a Basic chip later, assuming you're able to revive this machine. Quote Link to comment Share on other sites More sharing options...
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