sideburn

Did you check all the chips for continuity. Put one lead on the pins on the chip and then the other lead on the solder connection on the other side of the board. The problem with my black screen issue was ram and bad connections with the chip because the stock sockets are pretty crappy.

Ahh didn’t know the names. Dual wipe installed. Still going strong

I think we are good to go now! I cleaned all the pins on the ROM, swapped out the socket, dexoxited al the other sockets, rinsed the board in isopropyl, and blew it dry with an air gun. You can't even tell I swapped out the socket

I think I got it. It's either the ROM or the socket. I noticed the ROM tests are failing (red bars) when it starts acting up. I cleaned the pins and re-seated it but at an angle in the socket and so far so good. ** just swapped out the socket and i noticed the originals are those crappy ones with the metal tabs only on the insides so it doesn't grab the chip pins from both sides

I dont think its the Ram the ram tests are passing while the screen is going bonkers and i swapped out the new ram with the old and back. Yeah I reseated the chips many times and inspected the board. Its clean. New... I found an old 800xl in storage maybe the chips are socketed.. Sometimes when i power up it goes straight into the ram test. When it powers up my Atarimax and unocart work flawlessly. The only failures are the self test pages go whacky on the screen and it occasionally booting directly into the self test. if it doesn't it works perfectly consistently.

Well I Deoxited every chip on the board. The problem is totally random. comes and goes so I don't think it is the shield (its off for now until I sort it out) nor a bad connection. it has a life of its own so I think its a bad chip. I need to get some canned air and freeze the chips and see if that affects anything. ** I found another clue... if I let a test run for a while like the memory test, the flickering gets worse and worse over time like the sprites are flying all over the place on the screen and then when i force the screen to redraw by returning to the main menu it draws the screen perfectly and then starts messing up again. This might explain why games are working ok because the screen is redrawing a lot.

So the good news: The new cable got here today and it is 1,000 times better. Now the picture is how I remember it being. And the bad news: Today is also the day the 800xl decided to start acting up again... goes directly into self test and the screen is bonkers (but looks much better with the new cable! lol)... Time to get the Deoxit out...

Yeah kapton would be best for that I think. If it starts acting up again I’ll take it apart again, inspect the shielding, kapton insulate, and Deoxit the sockets. I’ve always been using my 130xe and left this 800xl in the box since it’s it such NOS condition but now I think I’m going to start using it instead. I forgot how much nicer they are.

I have a feeling that might have been what happened after I replaced the ram and it still wasn’t working. I had the bottom sheiks under the board just loose.

I agree. I bet it was only the ram. Yeah, I may pull it back apart and spray all the sockets. I’ve already got plenty of Deoxit. I love that stuff! I should have thought of that when I was re-seating all the chips. Yes, still issues with the 130xe convergence but it’s looking the 800xl video is about the same so I’m leaning towards it being the cable. I hooked RF to the 800xl and it looked much better. Still need to try that on the 130xe. Still got two more machines to fix. An Amiga 2000 that I don’t know what the heck happened to it, but it had major issues. Bad ram, blown Agnus and CIA chips, corroded battery & leakage, and more. I’ve finally got that working except for the hard drive. The disk activates and then solid HD activity LED. A Vectrex with a board that suffered bad corrosion. It’s now got a clock but that’s about it. Also an Apple ][ plus with bad ram that I just fixed. All of these have been in storage for a few years. In the same location. It’s interesting that all of them have / had bad ram and were all in working order before I boxed them up back then… I should probably get rid of a bunch of this stuff so I’ll have fewer broken things to fix every day and be forced to get some real work done! ? *The Ataris ain’t goin nowhere though. I still have all my floppies and programs from when I was 13 for those puppies.

That’s what I did. I think I’m good to go. Looks like it might have been a bad connection with the rom and a couple bad ram chips. thanks for the help everyone.

I think I got it. I think the shield thing was just a coincidence. I re-seated the ROMs and so far so good. Time will tell… I’d ditch the shields but this one is brand new. Rather keep it in mint / stock condition.

OK the plot thickens... All the sudden it got really bad and powers up straight into self test and the screen is going nuts... I take the whole thing apart again, remove the metal shield of the top and the bottom and set the board down on the workbench, power it up and its working flawlessly... self test page is nice and clean and passing all tests.. What gives! when i pu the thing back together it goes whacko on me.. Tempted to not put the damn shield on. what a PITA!

OK I got that RAM and this was weird. I swapped all 8 out and no change, black screen. I then swapped the only socketed chip I had in mu 130XE, the GTIA and no change.. I then try powering up again and boom its working! So I'm not sure if maybe the metal shield on the bottom was shifted and shorting something or what but it's working now. I then swapped the original rams one chip at a time and found two bad rams. The only issue now is the self test pages start going bonkers on the display but they are working properly. Only the display starts jittering around like crazy. Everything else works perfectly, I put my UNO cart in and ran a bunch of games and demos and they all work fine. So I am not sure why the Self Test screen is whacky...

I ordered that exact xe cable from them yesterday. I have not tried RF. Good idea, I will try that next.

I will keep you posted once they arrive. on a little off topic side note, my 130xe’s video convergence is way off. Especially the blue layer. Could that be my composite video cable or is it something else. I tested on a crt monitor, and lcd monitor, and a tv and it’s bad on all of them.

Great. Fingers crossed.

Oh no I ordered them already. Crap. oh you mean the apple ram.

Ok I just ordered 8 of these--> https://twistywristarcade.com/ram/47-4164-ram.html

I edited my post: apple rams are TMM416D-3

Ok cool. Yeah I don’t want to mess with it. It’s the only working atari I have

Yea I noticed the Hong Kong label when I had it apart. Do you know if my 130xe has socketed ram? Or do I have to open it up to find out. apple rams are TMM414D-3 I’ll look at that syscheck.

I know. It was hard to justify buying the hacko but after 30+ years getting angry at those damn spring loaded suckers I just folded and bought one and I have to say, when you DO need to desolder something it’s awesome!

I hear ya on the pads lifting and bodge wires. I am also repairing a vectrex and it was bodge wire city all day yesterday! This board is nasty corroded and impossible to not lift traces. But aside from that, usually there’s not a problem, I have a hacko desoldering gun, heat gun, flux, wick, etc. been soldering since I was a kid in the 80’s but I certainly do not have Louis Rossman surgery skills ? For ram donor boards I have 130xe, commodore sx-64, apple ][ plus with ram expansion cards, Amiga A1000, and Amiga 2000. I don’t know if my xe has socketed ram or not. The others do. I’ll have to open the xe up and have a look.

Hopefully he ram on my XE is socketed. All ram on 800xl is socketed. Does the 800xl need all the ram or can I pull 4 out and see if it boots? I have an Apple ][ as well, can I use that ram by chance? Not sure if I have the Freddy version. I uploaded a pic of the board.