Geose Posted October 11, 2017 Share Posted October 11, 2017 I have my Atari 5200 4 port model and i was messing around with it trying to do the vcs compatibility mod. I did the mod and it didn't seem to work. I went back and checked everything, nothing seemed to add up. The 5200 was still working at this point, and would play normal carts. I then kept on messing with it, trying different types of wires (I started with small solid core wire, then i switched it over to larger multi-core wire). Still not working with the adapter, I then figured out that the adapter might be broken, and I gave up on that mod. I then with the mod in place tried to reinstall the shield and reassemble the 5200. Now I'm not getting any video other than a black screen with static, and 4 of the ram chips are heating up. I then took out the mod in a panic to see if that would fix it, and it didn't. I'm pretty sure i shorted something, and I'm not sure what. the 4 ram chips are the only things that get hot (Pictured). The chips do not heat up if there is no cartridge installed. I've also messed around with the cartridge port and tried to remove excess solder. I have gone through the cartridge port and looked for shorts. None of the pins have continuity to each-other, other than the ground pins and pin 26. Pin 26 is connected to ground, I'm not sure if it is suppose to be. Ram chip model number: HM4816AP-4 I have a multi-meter and soldering iron. I can test anything you need me to. Spicy Ram Chips Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted October 11, 2017 Share Posted October 11, 2017 Pin 26 should not be connected to ground. It is VCC1. You have short somewhere on the board. 1 Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted October 11, 2017 Share Posted October 11, 2017 Are those ram chips in sockets? If so take them out and check continuity again between pin 26 of cart port and ground. 1 Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted October 11, 2017 Share Posted October 11, 2017 (edited) I found some on ebay http://www.ebay.com/itm/HM4816AP-4-HM4816AP-HM4816-Hitachi-DRAM-Lot-of-2-Pieces-/201122987084?hash=item2ed3dd3c4c:g:emAAAOSw-dBTuGhY but may be able to find cheaper elsewhere I don't know I think cheapest on ebay though because it already comes in lot of 2, for $5 and if you select 2 then you get 4 for $10 Those four you mentioned are probably definitely shorted but be aware that there also maybe more damage on the board, and also like I said get them out first and see if the short still exists on the motherboard. Once out you can also check b/t pins 8 and 16 of the chips, VCC and VSS for extra verification and they should show shorted because that is what is shorting it out on the motherboard more than likely. Edited October 11, 2017 by SignGuy81 1 Quote Link to comment Share on other sites More sharing options...
Geose Posted October 11, 2017 Author Share Posted October 11, 2017 I took them out and the short went away. I put them all back in one at a time and U23, seems to be causing the short. That is the 3rd from the bottom. does this mean I fried that one in particular? Or is this part of a larger problem? Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted October 11, 2017 Share Posted October 11, 2017 It should be the ram chip, are you saying that you can swap out different ones and no matter which one you place in that spot it shorts the board out? Or did it just happen to be the one you put in that spot when putting them back in shorted the main board out again? 1 Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted October 11, 2017 Share Posted October 11, 2017 Do a check on the individual chips too while out of the board, b/t pins 8 and 16 1 Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted October 11, 2017 Share Posted October 11, 2017 I think what you mean is that you were placing them back in they same spots they each came out of individually when you said U23 but it really shouldn't matter where you place them, what I'm getting at is the one that you put in U23, it would still short the board if you put that chip in U24, U22, etc. I believe the problem is the chip but I would like you to verify with me that we are on the same page with what I just said above. Also the other 3, you said all 4 was getting hot. Even if those aren't shorted like the one is I would still replace at least all of those 4 because even if the other 3 aren't a dead short like the one they are probably damaged as well. 1 Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted October 11, 2017 Share Posted October 11, 2017 I'm going to get off here for awhile gotta work out and hit the shower. Here is a link to the service manual, schematics start on page 20 of the PDF file. http://kickass.ddnss.org/html/library/documents/5200FSM.pdf And here is a link regarding the mod http://www.atarimuseum.com/videogames/consoles/5200/cx55.html At the bottom of that page look for page 3 for instructions(I didn't see a schematic with it), it says in step 6 to run the wire, and can be done on the back side of board but to avoid it due to risk of shorting, pretty much, not sure how you ran it though. Hope it helps. 1 Quote Link to comment Share on other sites More sharing options...
Geose Posted October 11, 2017 Author Share Posted October 11, 2017 I checked the other chips and that one is the only one with those pins shorted, the other 3 have a lower resistance than the top 4, but that could that they're just different brands. I don't know how to look for any other issues on the board, so i'm guess that's the problem. The VCS mod seemed simple, but i followed a different guide. I'm thinking that my adapter is just broken. I got it as "Untested" I guess I'll order some replacement ram chips and see what happens from there. 1 Quote Link to comment Share on other sites More sharing options...
Geose Posted October 15, 2017 Author Share Posted October 15, 2017 Replacing the ram chips fixed it. This was all a pain, since i broke it the day before my new games came in. All i had before was Pacman, so breaking it right before i got 6 new games was a huge letdown. Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted October 15, 2017 Share Posted October 15, 2017 Glad you got it working. What new games did you get? Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted October 15, 2017 Share Posted October 15, 2017 Almost forgot did you try the expansion module fix again? Quote Link to comment Share on other sites More sharing options...
Geose Posted October 17, 2017 Author Share Posted October 17, 2017 I haven't retried the fix. I'm kind of spooked after breaking it the first time. I'm probably going to get the adapter tested before I attempt the mod again. I'm gonna go find someone with a 2 port to test it, some shop is bound to have one. I got Centipede, Joust, missile command, jungle hunt, Qix, and digdug, They're quite an upgrade from pacman. 1 Quote Link to comment Share on other sites More sharing options...
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