Jorlando Posted December 3, 2017 Share Posted December 3, 2017 (edited) Hi; Today I received a shipment of imagic carts for my 7800 and found that none of them would fit well enough to run. I researched a bit on the forums to find a solution. The given solution was i.e: Remove external housing Find "cart cup" clip corners with scissors I did this to one of the corners and tested before proceeding any further to limit any damage. It worked for most of the games, but one, cosmic ark. So, I clipped another corner of the "cup" and when I went to test it the console wouldn't turn on!!! As far as I can tell (have not removed shield) there is no pieces lose. I ordered a Atari jr. in the mean time so I could still play most of my library, but I would really like to be able to fix the console; It ran beautifully before I mutilated it (no sticky buttons, no game problems, etc.) My Question; Any suggestions to what may be the problem? Any similar experiences? Thanks, - Justin Edited December 3, 2017 by Jorlando Quote Link to comment Share on other sites More sharing options...
DanthWader Posted December 3, 2017 Share Posted December 3, 2017 Do you have some photos to go on, did you completely remove the cart guide to clip the plastic or did you leave it on the board while you did the mod? Quote Link to comment Share on other sites More sharing options...
+Mitch Posted December 3, 2017 Share Posted December 3, 2017 Check and see if you cracked the solder joint on the voltage regulator. It is attached to the big heat sink right behind the cart port. Mitch Quote Link to comment Share on other sites More sharing options...
Jorlando Posted December 4, 2017 Author Share Posted December 4, 2017 I left it on the unit. I didn't know how to remove the shielding at the time. Update: My father and I opened up the unit to see if there was any internal damage. Everything seemed fine, but we did find the source of the problem, a piece I totally overlooked. The transformers cables got stripped right below the neck. The wires most of crossed and shorted the unit. We read the transformer to see how many volts it was outputting; It read at 14 volts. We tested to see if the unit shorted, or if it was just the transformer by taking two 9v batteries wiring them in parallel and running it through the unit. It didn't turn on. Do you think it could be just the voltage regulator that got shorted, or the whole unit got fried? p.s Thanks for all the help, I'm fairly new to console repair. I have a little experience in electrical engineering for sound circuits, but my father's an electrical engineer. We may just take it to a local electric repair shop soon. If nothing fixes the problem, I might just send someone here the console deck for 10$ and shipping, Don't want it to go to waste, being a limited supply. - Justin Quote Link to comment Share on other sites More sharing options...
Jorlando Posted December 4, 2017 Author Share Posted December 4, 2017 Check and see if you cracked the solder joint on the voltage regulator. It is attached to the big heat sink right behind the cart port. Mitch I'll double check to see if that's case. Thanks for the help. Quote Link to comment Share on other sites More sharing options...
nick3092 Posted December 6, 2017 Share Posted December 6, 2017 There is no service manual with troubleshooting steps available for the 7800 that I am aware of. But the schematics are readily available. Given your dad is an EE, he should be able to use that to accomplish basic troubleshooting. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted December 6, 2017 Share Posted December 6, 2017 Here is part of the service manual. Curt found it several years ago. Mitch 7800 service manual 2.pdf 7800 service manual.pdf Quote Link to comment Share on other sites More sharing options...
Inky Posted December 6, 2017 Share Posted December 6, 2017 1 Quote Link to comment Share on other sites More sharing options...
Trebor Posted December 7, 2017 Share Posted December 7, 2017 Here is part of the service manual. Curt found it several years ago. Mitch For posterity's sake... http://atariage.com/forums/topic/216763-7800-theory-of-ops-ts-guide/ ...plus the above thread includes your awesome parts list for the 7800. Quote Link to comment Share on other sites More sharing options...
+wongojack Posted December 7, 2017 Share Posted December 7, 2017 An easy test is to see if the 5v line on the joystick port is getting 5v. The pin diagram is easy to find everywhere and ground is pretty much connected (as per usual) across the entire 7800 board. You can pull this test off without even removing the case if you test the right pins. At least then you could tell if power was getting into the 7800 at all. Of course, testing voltage right on the regulator would probably tell you if that Heatsink is the issue. Still, exploring carefully with voltage readings is a good first step. I have one 7800 where the previous owner tried to BYO power adapter and got the polarity crossed (or something). It's fncked (power socket removed), but still plays 2600 games in B&W when I hook the voltage up correctly - weird. Quote Link to comment Share on other sites More sharing options...
Jorlando Posted December 8, 2017 Author Share Posted December 8, 2017 Thanks for all the help! I'll put some more work into it this weekend and report back. Quote Link to comment Share on other sites More sharing options...
Jinks Posted December 10, 2017 Share Posted December 10, 2017 Capture.PNG Thats how I fix em.. Quote Link to comment Share on other sites More sharing options...
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.