DjGhumba Posted September 13, 2019 Share Posted September 13, 2019 Hi guys a few weeks ago I decided that I have to upgrade my Atari 400 from 16k ram to 48k so I ordered a a kit from eBay so my problem is I did everything following the instructions checking every soldering point double checking for any short so everything looks perfect according to the instructions after assembly everything back I proceeded to turn on as a result I got a black screen and nothing happened so I decided communicated with the seller to see if i miss something after a good and friendly conversation he decide generously sent me a new kit just in case I fry any of the chips when I seldered do to overheat finally the new kit arrived and I proceeded to start over all the process this time taking care of the heat ,after done I assembled everything back, turn on the Atari and the results still the same. I’m doing this mod on a worked 16k board so doing some troubleshooting I have a spare 16k board when a hook my spare board everything works fine on the Atari but not on the modded one I have some pictures of what I did for reference so please I need your help to see if I can resolve my problem. Thanks.... Quote Link to comment Share on other sites More sharing options...
Wrathchild Posted September 13, 2019 Share Posted September 13, 2019 (edited) Can't help I'm afraid though curious if you had seen/considered the 48K/52K board before opting got the upgrade? I have one in a 400 and it's great. Edited September 13, 2019 by Wrathchild Quote Link to comment Share on other sites More sharing options...
DjGhumba Posted September 13, 2019 Author Share Posted September 13, 2019 Here some pictures of what I did... Quote Link to comment Share on other sites More sharing options...
DjGhumba Posted September 13, 2019 Author Share Posted September 13, 2019 Wrathchild do you think that I can get that board in 2019? I did some research over the internet and it’s looks like that is not on the market anymore.. Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted September 13, 2019 Share Posted September 13, 2019 contact Jurgen (username tf_hh) on here: https://atariage.com/forums/profile/15670-tf_hh/ i fitted his RAM and CPU boards to my 400 and theyre a great upgrade! Quote Link to comment Share on other sites More sharing options...
Nezgar Posted September 13, 2019 Share Posted September 13, 2019 I recall 400 48K upgrades require at least 1 wire from the memory board to be soldered to the motherboard. Was that a step in your instructions? Quote Link to comment Share on other sites More sharing options...
DjGhumba Posted September 14, 2019 Author Share Posted September 14, 2019 Nezgar I’m using the Gary A. Crowell instructions on the photos that I post in this topic are all soldered cables. Quote Link to comment Share on other sites More sharing options...
Nezgar Posted September 14, 2019 Share Posted September 14, 2019 3 hours ago, DjGhumba said: Nezgar I’m using the Gary A. Crowell instructions on the photos that I post in this topic are all soldered cables. Ah K. I haven't installed that upgrade and I'm really not familiar with it, but I compared your motherboard wiring to the diagram in the Gary A. Crowell PDF, but it appears to match... The instructions also mention cutting 4 traces on the back side of the 16K board which you do not show in your pictures, maybe you could add a photo of that? Other than that, someone else with more experience with this one will have to review... Edit: Oops, yes, missed the top photo is there, and does indeed show the back side of the 16K board... Quote Link to comment Share on other sites More sharing options...
BillC Posted September 14, 2019 Share Posted September 14, 2019 7 minutes ago, Nezgar said: Ah K. I haven't installed that upgrade and I'm really not familiar with it, but I compared your motherboard wiring to the diagram in the Gary A. Crowell PDF, but it appears to match... The instructions also mention cutting 4 traces on the back side of the 16K board which you do not show in your pictures, maybe you could add a photo of that? Other than that, someone else with more experience with this one will have to review... The top image in post #3 is the solder side of the RAM PCB, there are what appear to be 4 cut traces near the card edge contacts. Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted September 14, 2019 Share Posted September 14, 2019 here is the wiring mod for tf_hh's 48k upgrade. its a little less complicated 3 Quote Link to comment Share on other sites More sharing options...
SS Posted September 15, 2019 Share Posted September 15, 2019 13 hours ago, xrbrevin said: here is the wiring mod for tf_hh's 48k upgrade. its a little less complicated That is some TIGHT wiring work! Very nice job. 3 Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted September 15, 2019 Share Posted September 15, 2019 42 minutes ago, SS said: That is some TIGHT wiring work! Very nice job. Solid core wire and measured very precisely. I’d tack down that bottom right corner with a bit of hot glue or something myself, but with the bottom RF shield installed, that wire is very likely not going to move anyway. Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted September 15, 2019 Share Posted September 15, 2019 12 hours ago, DrVenkman said: Solid core wire indeed it is, i think i will glue the corner down if i ever need to open it up again. it does look a bit wayward in the pic.. Quote Link to comment Share on other sites More sharing options...
DjGhumba Posted September 21, 2019 Author Share Posted September 21, 2019 Hey guys today I fix my problem I try the claus b method and now everything works perfect no black screen and finally got 48k of ram, I hook my SDrive max and all games runs well... 9 Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted September 21, 2019 Share Posted September 21, 2019 great success! 2 Quote Link to comment Share on other sites More sharing options...
okcid Posted September 14, 2020 Share Posted September 14, 2020 I followed Gary Crowell instructions and cant get mine to work either... To me than an issue with T3 connection as seems not to connect to pin 11 of the Z503 chip ...as in his final mod diagram. As these instructions are quite old now...I suspect im at fault..and not the diagram ..... Quote Link to comment Share on other sites More sharing options...
cwilbar Posted September 15, 2020 Share Posted September 15, 2020 On 9/14/2019 at 7:53 AM, xrbrevin said: here is the wiring mod for tf_hh's 48k upgrade. its a little less complicated Nice clean install there ! ? Quote Link to comment Share on other sites More sharing options...
Jeffrey Worley Posted March 24, 2023 Share Posted March 24, 2023 On 9/21/2019 at 3:03 AM, DjGhumba said: Hey guys today I fix my problem I try the claus b method and now everything works perfect no black screen and finally got 48k of ram, I hook my SDrive max and all games runs well... I know what the problem with this upgrade was. You absolutely HAVE to use plain 74 or 74LS parts only. The Crowell-Davies mod exploits the longer gate delay of these chips and since the S and F and HCT versions operate with much shorter delays, the modification is broken. I learned this from Claus Buchholz himself, though I still do the Crowell-Davies mod, I am careful to source the older 74 or 74LS chips to do them. best, Jeff 3 Quote Link to comment Share on other sites More sharing options...
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