Pfaffa #1 Posted August 18, 2020 Hi, I recently bought a 800xl which I am attempting to get working. We accidentally powered the system on with the GTIA off by one peg (to the right) . Did we permently damage it? Quote Share this post Link to post Share on other sites
+DrVenkman #2 Posted August 18, 2020 Well, if the system was powered and your power supply was producing the expected +5V DC, you just put that voltage into the A0 line of the address bus. Kind of hard to be sure if you damaged anything that way or not. Do you have any kind of tools or test equipment to help you repair this system, or are you just chip-swapping? Quote Share this post Link to post Share on other sites
Rybags #3 Posted August 18, 2020 The only way to find out is put it in properly and see if it works. Generally a fried chip won't hurt the rest of the system. Quote Share this post Link to post Share on other sites
Pfaffa #4 Posted August 18, 2020 Just trying to get the system up, we are getting either a black or red screen (we are colorblind and the lcd is old). I have a voltmeter with discontinuity checking and that is about it. We were pulling up chips and reseating them to see if that fixed the system. Quote Share this post Link to post Share on other sites
+DrVenkman #5 Posted August 18, 2020 1 minute ago, Pfaffa said: Just trying to get the system up, we are getting either a black or red screen A red/green screen usually indicates that the SALLY, ANTIC and GTIA are okay but something is preventing the system from booting up. Often it's the OS ROM but it might be any number of other things as well. 1 Quote Share this post Link to post Share on other sites
+mytek #6 Posted August 18, 2020 Well behaved chips should have their I/O set to inputs when first powered up. So there is a good chance that the GTIA is ok. And as it has already been suggested, best way to know is to properly re-install and see. Quote Share this post Link to post Share on other sites
Pfaffa #7 Posted August 18, 2020 Still working but we made to the system test screen 1 Quote Share this post Link to post Share on other sites
TGB1718 #8 Posted August 18, 2020 11 hours ago, mytek said: Well behaved chips should have their I/O set to inputs when first powered up. If it's one pin out, it's not going to power up 🙂 Quote Share this post Link to post Share on other sites
+mytek #9 Posted August 18, 2020 (edited) 2 hours ago, TGB1718 said: If it's one pin out, it's not going to power up 🙂 Yes you are correct in that being one pin offset will not power-up the chip (VCC not connected to 5V). Edited August 18, 2020 by mytek Deleted completely wrong presumptions Quote Share this post Link to post Share on other sites
Pfaffa #10 Posted August 18, 2020 Everything is working thx everyone. We still need to adjust the POTs to the correct image, I am getting everything setup for it right now. I am happy to have a working Atari, a 400 was my first computer. 4 Quote Share this post Link to post Share on other sites