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....