techknight Posted August 11, 2018 Author Report Share Posted August 11, 2018 I think I changed the PAL set already. But I cannot honestly remember. Quote Link to post Share on other sites
bibilit Posted August 12, 2018 Report Share Posted August 12, 2018 Quote I think I changed the PAL set already. But I cannot honestly remember. You changed the PAL set, was said on one of your earlier post. As i am lazy, tried to piggyback the PALs first... hoping it will help troubleshooting the board, and worked. Quote Link to post Share on other sites
techknight Posted August 12, 2018 Author Report Share Posted August 12, 2018 Yea its been to long. I bought some new ICs for it and I sat it all on the shelf and I havent looked back yet. been way too busy with my standard day job. I cant wait until we get enough capital in where we an hire dev teams and customer service people so I aint gotta do it. Quote Link to post Share on other sites
bibilit Posted August 13, 2018 Report Share Posted August 13, 2018 @techknight The SE/30 has two different sets (revisions) of PALs... i was lucky as apparently the one i changed is common in the two revisions. For troubleshooting purposes, can i use one set instead of the other ? Quote Link to post Share on other sites
techknight Posted August 17, 2018 Author Report Share Posted August 17, 2018 Either set will work. as long as they are all a matched set. Quote Link to post Share on other sites
Bolle Posted August 17, 2018 Report Share Posted August 17, 2018 Even the ones from the early board revision that has the patch wire installed? Or does that wire make the routing the same as on the later boards? Never had to work in depth on one of the early boards yet. Quote Link to post Share on other sites
techknight Posted August 18, 2018 Author Report Share Posted August 18, 2018 I havent tried a patchwire board. I usually dont see those. I know there is a PAL set thats 6XX and a pal set thats 7XX and I have swapped the two before. Quote Link to post Share on other sites
NE555 Posted November 17, 2018 Report Share Posted November 17, 2018 @techknight Did you ever get the issue of this thread resolved? Quote Link to post Share on other sites
techknight Posted November 19, 2018 Author Report Share Posted November 19, 2018 Nope. I have been busy with work so its been on the backburner. Way too long, I know. Quote Link to post Share on other sites
NE555 Posted November 20, 2018 Report Share Posted November 20, 2018 I hear ya. I got a SE/30 that does exactly the same thing. Quote Link to post Share on other sites
bibilit Posted November 20, 2018 Report Share Posted November 20, 2018 Have you tried swapping PAL's as i did ? solved the issue for me. Quote Link to post Share on other sites
NE555 Posted November 20, 2018 Report Share Posted November 20, 2018 I swapped the PAL (all of them) and cleaned the pins, I swapped the PAL sockets, I swapped all the 8 bit shift registers, I swapped the ROM SIM socket and I swapped the memory SIM sockets. I replaced the capacitors and some of the resistors underneath the PAL chips. Quote Link to post Share on other sites
NE555 Posted November 27, 2018 Report Share Posted November 27, 2018 any more or other suggestions? Quote Link to post Share on other sites
BadGoldEagle Posted November 27, 2018 Report Share Posted November 27, 2018 (edited) Well, if you've swapped every suspect chip on that board, the only things that could be bad are traces... I know that's kind of a stupid suggestion, but I would go bad trace hunting with a schematic if I were you. https://www.macintoshrepository.org/875-macintosh-se-30-schematics-and-repair Edited November 27, 2018 by BadGoldEagle Quote Link to post Share on other sites
NE555 Posted November 27, 2018 Report Share Posted November 27, 2018 I noticed that there is a slight difference between the OP's screen output vs mine. My lines seem to go through the mouse icon and the question mark disk. Quote Link to post Share on other sites
techknight Posted November 27, 2018 Author Report Share Posted November 27, 2018 yea thats commonly fixed. If you have already changed out UE8, then check the traces to it. But more importantly, check the VRAM I have seen those go bad as well. Quote Link to post Share on other sites
NE555 Posted November 27, 2018 Report Share Posted November 27, 2018 The LS166 is new. I am not 100% sure anymore if I changed out the VRAM. I'll check the UE8 traces again. Quote Link to post Share on other sites
NE555 Posted November 28, 2018 Report Share Posted November 28, 2018 I think I found it Pin 5 on the ls166 (vid3) to UC7 pin 23 is OL. Pin 5 to via on the ls266 is OL. via to pin 23 on UC7 is .3ohm a closer look reveals that the pad is disconnected from the Via thank you for the help techknight Quote Link to post Share on other sites
NE555 Posted November 28, 2018 Report Share Posted November 28, 2018 and here is the result Quote Link to post Share on other sites
techknight Posted November 29, 2018 Author Report Share Posted November 29, 2018 Yeap, I figured as much. the board I have is way worse. lol. Quote Link to post Share on other sites
redruM69 Posted September 19, 2019 Report Share Posted September 19, 2019 Sorry to dig up a dead thread. Techknight, did you ever find anything on this? I have precisely the same video bug, but cant seem to figure it out. Both VRAM's and UE8 have been replaced. Tested all traces to and from VRAM. I still get vertical stripes with a slightly abnormal disk icon. Looks identical to your screenshot. Quote Link to post Share on other sites
redruM69 Posted September 20, 2019 Report Share Posted September 20, 2019 Also, I have tried swapping all 5 PALs with known good. Quote Link to post Share on other sites
redruM69 Posted September 27, 2019 Report Share Posted September 27, 2019 Bump? Quote Link to post Share on other sites
redruM69 Posted October 10, 2019 Report Share Posted October 10, 2019 ISSUE RESOLVED! Techknight, you may want to add this to your notes. It appears that Texas Instruments SN74HC166DRG4 is NOT a valid replacement for the the 166 shift register @ UE8. It causes the discussed artifacts. I swapped it out again, but this time with a Toshiba 74HC166D, and the issue completely resolved! Quote Link to post Share on other sites
Bolle Posted October 11, 2019 Report Share Posted October 11, 2019 (edited) I would always use the appropriate 74LS166 instead of a 74HC. It’s supposed to act the same but as you see it might not always do. Edited October 11, 2019 by Bolle Quote Link to post Share on other sites
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