jschaap26 #1 Posted January 8 I've got a 99/4A that when powered on outputs black video sustained screech when turned on. I've seen other post about this same problem and have tried what I believe are all the simple fixes including: - Checking the power supply (I've tested the voltages and it's confirmed working for two other 99's) - Removing the cartridge connector - Reseating all the sockets chips - Looking for anything on the board that is damaged I had a spare 9918A and swapping that in but got the same results. I have a logic probe and could run tests (if given VERY specific instructions) but no soldering skills. Thanks in advance for your insights. Quote Share this post Link to post Share on other sites
+chue #2 Posted January 8 The BSOD can be caused by a variety of bad chips including: VDP, CPU, RAM (16k), RAM (256b), ROM, GROM. There is a 3 part series on YouTube, in which a guy repairs his: The problem with his TI was the CPU, but that doesn't mean that yours has the same problem. Quote Share this post Link to post Share on other sites
Stuart #3 Posted January 8 Personally I'd start by replacing the two MCM6810 RAMs, but you need at least some level of soldering skills to do it. 1 Quote Share this post Link to post Share on other sites
+arcadeshopper #4 Posted January 8 check clock, then rams Quote Share this post Link to post Share on other sites
AtariNostalgia #5 Posted January 9 I know how you feel. My Beige TI has the same symptoms, but attempting to repair it is too complicated as there are way too many failure points. Quote Share this post Link to post Share on other sites
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