+xucaen Posted July 14, 2018 Share Posted July 14, 2018 I ran the system test cart (salt?) And it is showing 14 errors. I'm really not sure what to make of it. Is this normal or should I be concerned? should I start thinking about having components replaced? I made a video of the tests. This is my first time ever running it so I'm hoping if somebody watches this and they see something out of place maybe they can help me understand it. Thanks everyone! Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted July 14, 2018 Share Posted July 14, 2018 I thought the Super SALT required an external diagnostics box hooked up to the SIO and JoyStick ports in order to properly function for some of those tests. 2 Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 14, 2018 Author Share Posted July 14, 2018 I thought the Super SALT required an external diagnostics box hooked up to the SIO and JoyStick ports in order to properly function for some of those tests. Yeah I have no idea what I'm doing. I'm just learning as I go. I'm using a new Ultimate cart I just bought and I'm going through a bunch of games. Most work but some don't. I'm playing Dark Chambers and it keeps crashing. Not sure if there something wrong with the computer or if this is the result of a corrupted car image. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted July 14, 2018 Share Posted July 14, 2018 I thought the Super SALT required an external diagnostics box hooked up to the SIO and JoyStick ports in order to properly function for some of those tests. All of the SALT carts require the test box connected to get the full suite of tests with valid results. The individual tests tell you as much on-screen. Those GTIA, POKEY and PIA errors are for sure related to the test box (trigger lines for the controllers, potentiometer/paddle inputs, and the I/O tests for PIA). I don't know what the timers test actually does so I can't comment on that one. 1 Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 14, 2018 Author Share Posted July 14, 2018 Oh boy... I ran the built in memory test again and let it run for a while. Everything was green, then all of a sudden one of the ROM bars turned red and the last 8 RAM squares went missing. Edit: ran a few more times, got red ROM with 48k green squares. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted July 14, 2018 Share Posted July 14, 2018 Yeah, that might explain why Dark Chambers crashed on your Ultimate Cart. After reading your earlier post, I ran it on my UNO Cart without a problem through two entire levels. I did notice in your video, after the memory test there were a couple stray characters on the grid. It SHOULD be all dashes, as I recall, if everything comes up clean. 1 Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 14, 2018 Author Share Posted July 14, 2018 ...and the last 8K of RAM disappears.. :,( At this point I'll be looking for someone who can troubleshoot and repair this 800xl. Maybe get a memory upgrade while they're in there. Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 14, 2018 Author Share Posted July 14, 2018 ...and there goes the other ROM. Oh I don't feel so good... Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted July 14, 2018 Share Posted July 14, 2018 I'm curious if this would be a sign of a failing MMU ( and not the RAM/ROM itself ). Instead of sending it out for repair, why not try to repair it yourself first. Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 14, 2018 Share Posted July 14, 2018 Or a failing power supply taking out chips. Better pull out the voltmeter and see if you have something a lot higher than 5 VDC. 2 Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 14, 2018 Author Share Posted July 14, 2018 Instead of sending it out for repair, why not try to repair it yourself first. Because I'm a novice at soldering and I know I would ruin the motherboard. I have three Atari 2600 boards sitting in a box waiting for me to practice on and would rather have a professional job done on the 800xl. I probably will open it up just to see if the chips are socketed or not.. but probably they are not. Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 14, 2018 Author Share Posted July 14, 2018 Or a failing power supply taking out chips. Better pull out the voltmeter and see if you have something a lot higher than 5 VDC. I have another thread in which I talk about the power supply.. http://atariage.com/forums/topic/280360-new-800xl-owner/ Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 14, 2018 Author Share Posted July 14, 2018 I'm curious if this would be a sign of a failing MMU ( and not the RAM/ROM itself ). Instead of sending it out for repair, why not try to repair it yourself first. Now I am curious and reading about the MMU.. how would I go about testing it to see if it is failing? For that matter, how would I go about testing the RAM and ROM? Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 14, 2018 Author Share Posted July 14, 2018 dang it kheller2 now you got me thinking. I downloaded the service manual, and yes it looks like it could be as you say.. so I guess I'll have a look to see what the chips look like before I decide I can't do it myself (although I am fairly certain I can not. ) These are the relevant excerpts from the service manual: Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted July 15, 2018 Share Posted July 15, 2018 Reseat all the chips first if they are socketed. Almost sounds like a thermal issue, (if not a power issue). Does it pass the test fine after being cold? 1 Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 15, 2018 Author Share Posted July 15, 2018 Reseat all the chips first if they are socketed. Almost sounds like a thermal issue, (if not a power issue). Does it pass the test fine after being cold? Without powering off the computer, I ran the test for over an hour. When I restart the test, ROM is green until the second or third iteration. Quote Link to comment Share on other sites More sharing options...
Keneg Posted July 15, 2018 Share Posted July 15, 2018 I had last 8k of ram missing on my 800xl. I checked the voltage across the power jack. It was something like 5.16 volts with the computer off and dropped to less than 4 volts with the computer on. I built a power supply and it has been fine ever since. So try checking power supply voltage first. 1 Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 15, 2018 Author Share Posted July 15, 2018 I had last 8k of ram missing on my 800xl. I checked the voltage across the power jack. It was something like 5.16 volts with the computer off and dropped to less than 4 volts with the computer on. I built a power supply and it has been fine ever since. So try checking power supply voltage first. I'm searching for how to test the power supply. I've never done that before. Any tips? This is a new power supply from Best Electronics. I'm not using the old one any more but maybe the old one had already damaged the ROM either before the previous owner sold it to me or after I received it... Not sure. At least I'm not seeing any red RAM blocks so hopefully the repairs will be minimal if it needs repairing. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted July 15, 2018 Share Posted July 15, 2018 I'm searching for how to test the power supply. I've never done that before. Any tips? This is a new power supply from Best Electronics. I'm not using the old one any more but maybe the old one had already damaged the ROM either before the previous owner sold it to me or after I received it... Not sure. At least I'm not seeing any red RAM blocks so hopefully the repairs will be minimal if it needs repairing. I'm pretty sure that XL power supply will be good unless it's the dreaded "Ingot." The pinout is here. As long as any one of the +5V and ground pins are connected, it'll be fine. http://atariage.com/forums/topic/184792-800xl-power-supply-connector/?p=2323544 1 Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 15, 2018 Author Share Posted July 15, 2018 Here is the new power supply: 1 Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted July 15, 2018 Share Posted July 15, 2018 That's about the best model XL power supply there is - big enough that heat dissipation isn't an issue, it can be opened and serviced if it's ever necessary ... I doubt that's what the issue is. 2 Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 21, 2018 Author Share Posted July 21, 2018 I have taken apart my 800xl. I am looking for 4 chips as per the service manual: U2 IC Decoder C061428 U3 IC Mem Mngt Unit (MMul B) C061618 U4 IC (8kx8) Basic ROM RevB C060302 U5 IC (16kx8) OS ROM C061598 I can find U4 and U5 but I can not find U2 and U3. Maybe those do not exist on this revision of the board? Here is a short video passing over the entire board. Are U4 and U5 the only chips I would need to replace? Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted July 21, 2018 Share Posted July 21, 2018 (edited) I have taken apart my 800xl. I am looking for 4 chips as per the service manual: U2 IC Decoder C061428 U3 IC Mem Mngt Unit (MMul B) C061618 U4 IC (8kx8) Basic ROM RevB C060302 U5 IC (16kx8) OS ROM C061598 I can find U4 and U5 but I can not find U2 and U3. Maybe those do not exist on this revision of the board? U2 is a bog-standard 74LS138N logic chip. Any electronics retailer should have them. Mouser has them for 84 cents apiece, about 65 cents in quantities of ten. Shipping will kill you though. I'm sire Digi-Key and the other electronics stores are about the same. The others are Atari-specific. Best Electronics will have them. Shoot them an email and ask for pricing and payment info. EDIT: misunderstood your question. U3 is the MMU. It's directly underneath the cartridge connector. U2 is the 74LS138N chip directly below that one. They're common to every 800XL board revision, so far as I know. Edited July 21, 2018 by DrVenkman 1 Quote Link to comment Share on other sites More sharing options...
+xucaen Posted July 21, 2018 Author Share Posted July 21, 2018 I found U2 and U3. so, umm... never mind. 1 Quote Link to comment Share on other sites More sharing options...
Roydea6 Posted July 21, 2018 Share Posted July 21, 2018 Look at 45 sec again.. MMU below Cartport. 1 Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.