lolof Posted February 9, 2020 Share Posted February 9, 2020 (edited) I was assembling a finalgrom99 and unfortunately I got a broken CPLD from China..... The TI with the not working finalgrom99 started with blue screen and strange noise when flashing the CPLD for the first time. It's maybe a coincidence but after this, the screen from my TI was broken. See picture. I replace the FG99 CPLD with another one and it worked on an another TI-99/4A. Problem is, my first TI was my best one ? What can be broken ? I do not really know where to start.... I never repaired a TI, it's the first problem I have on TI.... Edited February 9, 2020 by lolof Quote Link to comment Share on other sites More sharing options...
+arcadeshopper Posted February 9, 2020 Share Posted February 9, 2020 in the faq here: https://www.arcadeshopper.com/wp/?p=312 search for: Scrambled/Garbled screen graphics/text Quote Link to comment Share on other sites More sharing options...
HOME AUTOMATION Posted February 9, 2020 Share Posted February 9, 2020 https://www.ninerpedia.org/wiki/Troubleshooting ...close Quote Link to comment Share on other sites More sharing options...
+mizapf Posted February 9, 2020 Share Posted February 9, 2020 We don't have that pattern on Ninerpedia. Too bad the colors in the photograph are not well visible. @lolof, could you please try to take another picture with a better quality? (Usually I'd say, try different shutter times, but this was when photos were taken by devices that were designed for them, and not by devices for communication.) Quote Link to comment Share on other sites More sharing options...
lolof Posted February 9, 2020 Author Share Posted February 9, 2020 Thanks, I will have a look in the FAQ. It's connected on a old TV and I can't do a better picture with what I have here..... I have somewhere a LCD TV that should work. I will search for it and try to post a better picture. Quote Link to comment Share on other sites More sharing options...
lolof Posted February 9, 2020 Author Share Posted February 9, 2020 (edited) @mizapf Done, thanks to a old Samsung LCD TV ! I hope this picture is ok for you. The TI is connected on TV by Scart cable. It's a french TI.... I will start replace the vram one by one and see if it's the problem. Edited February 9, 2020 by lolof Quote Link to comment Share on other sites More sharing options...
+mizapf Posted February 9, 2020 Share Posted February 9, 2020 OK, looks good. I tried to create this output by manipulating the VRAM write function in MAME; the closest hit was when I set bit 0x20 to 1 for addresses higher than 0x0800. This could mean that bit 2 is stuck to 1 starting from the second kilobit of the 16 kbit chip. See the board on https://www.ninerpedia.org/wiki/Troubleshooting to see which chip is affected (number 2). 1 Quote Link to comment Share on other sites More sharing options...
kl99 Posted February 9, 2020 Share Posted February 9, 2020 usually the faulty chip is super hot. Quote Link to comment Share on other sites More sharing options...
lolof Posted February 9, 2020 Author Share Posted February 9, 2020 (edited) Thank you very much, I will start with that Chip. I should receive new chip this week. I will report the result. I just want to ask, one modified 4164 will work with the other 4116 well or should all vram be changed to 4164 ? The chips I ordered are 4164..... I saw here I could use 4164 with a simple mod : Edited February 9, 2020 by lolof 1 Quote Link to comment Share on other sites More sharing options...
+arcadeshopper Posted February 10, 2020 Share Posted February 10, 2020 18 hours ago, lolof said: Thank you very much, I will start with that Chip. I should receive new chip this week. I will report the result. I just want to ask, one modified 4164 will work with the other 4116 well or should all vram be changed to 4164 ? The chips I ordered are 4164..... I saw here I could use 4164 with a simple mod : awesome definitely report back how it went 1 Quote Link to comment Share on other sites More sharing options...
lolof Posted February 15, 2020 Author Share Posted February 15, 2020 I got 8 the new memory (TMS4164-15LNJ) and solder 4 of them. I want to change them all but I have to wait to receive 4 sockets I ordered. It's already working. At least, I am getting the bootscreen without graphics corruption. For a complete test, I have to wait to receive the last sockets and put the TI all together again. Unfortunately, I can't confirm 100% that this was the number 2 broken. I did a mistake and removed the wrong one at first (Nr1). And as I cut the legs from IC, I could not test again with the old chips and I removed directly after a second one (Nr2) without testing. So, it's the Nr.1 or Nr.2. But surely Nr.2 as mizapf could reproduce almost the same problem on the emu. Here a picture of the actual status. Waiting the last 4 sockets... Thanks to all of you for the help. 5 Quote Link to comment Share on other sites More sharing options...
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