pluto63 Posted May 21, 2019 Share Posted May 21, 2019 I need some help and a fresh view on a 130xe repair, at present time video out is dark red screen. When I got the board found that someone attempted to socket the OS destroying a good number of vias, I restored the damage and checked all the connection. I then socketed all major ic and ram. Now all ic are checked working on another board, what Im getting is all data lines stacked high. Im getting a pulse at startup or reset and then they stack high. Removing the cpu and checking lines am getting a LOW signal probe on pin 30 that is data line 5. Ive checked multiple times all the D5 trace on the pcb and could not found anything wrong. Below a video with scope and board photos. Any idea on what to try is welcome. Not recapped yet but I dont see how a dry capacitor could affect D5. 2 Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted May 21, 2019 Share Posted May 21, 2019 This might help 130XE - Sams ComputerFacts.pdf 2 Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted May 21, 2019 Share Posted May 21, 2019 and this 130xe Hardware Manual.pdf 1 Quote Link to comment Share on other sites More sharing options...
pluto63 Posted May 21, 2019 Author Share Posted May 21, 2019 Already checked schematics multiple times, thank you, and a small correction to my first post the Data Lines are stacked Low not High 3-4 seconds after power on or reset. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted May 21, 2019 Share Posted May 21, 2019 Failed address logic IC on the board? Quote Link to comment Share on other sites More sharing options...
pluto63 Posted May 22, 2019 Author Share Posted May 22, 2019 All ic checked working, also recapped but no changes. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted May 22, 2019 Share Posted May 22, 2019 All ic checked working, also recapped but no changes. If “all ic” includes the 74-series logic chips, then you’ve either got a short on the board somewhere or a bad socket. There aren’t really any other things it could be. Quote Link to comment Share on other sites More sharing options...
+tf_hh Posted May 22, 2019 Share Posted May 22, 2019 All ic checked working, also recapped but no changes. You didn´t mention (in the text), which signal this is: When the alignment of 0V is the same as the first signal you showed, then this signal is bad in any way. It looks like it never goes below 2 volts, but for a clock signal it should be. 1 Quote Link to comment Share on other sites More sharing options...
pluto63 Posted May 24, 2019 Author Share Posted May 24, 2019 Signals are pin 29 ok, pin 30 not ok, and pin 31 on cpu socket ( with no cpu inside). That is the Data 5 line that I’ve checked countless times for shorts, solder blobs or anything else. Anyway i’m done with this board, it needed a fresh view so I send it to Bas to continue tinkering with it. Will update with his findings. 2 Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted May 25, 2019 Share Posted May 25, 2019 (edited) The board has nicks as well as butchered pads and traces, I would look for more of the same.... double check the repairs that are already done and trace out with a dmm that traces under sockets etc are still in good shape. Looks like an errant solder flake or two as well Edited May 25, 2019 by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
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