RetroHospital
Experienced Member
Hey everyone,
I've got this Apple II europlus on my bench since months.
After a difficult repair it's now working as it should, however I can't solve what seems to be the last problem with it.
The display (may it be CRT or LCD) displays thin vertical lines, ranging from barely visible (when there are not additional cards on the expansion slots) to super bright visible (with 4 or more cards)
When I talked about my problem, new people joined my thread on AppleFritters ; this problem seems to affect half a dozen of people, but we're not making progress.
It's up to the point I can see this same issue even on A2 Europlus for sale on Ebay.
This seems to be widespread. And difficult to debug, beeing a subniche ( Apple II -> PAL monochrome )
Indeed, I have the feeling this problem is europlus specific (I don't think it affects NTSC)
I spent a lot of time trying to switch ICs (on the clock mainly), probe the bus, etc...
All I can say for sure is this appears when you add cards in the slots, and the more you add, the worse it becomes.
The two first pictures show my own A2 with one, then 4, cards added.
Interestingly : sometimes, removing a single chip out of a card (eg remove the LS323 on the Disk II card) makes the problem disappear.
This problem is NOT related to floppies. It really appears when you add a WORKING expansion card.
It disappears if you remove a single critical chip out of an expansion card (enough to make it inoperative).
I can't swap the PSU (but other AppleFritters forum says they did, with no luck). I have seen more noise on the 5V rail the more I add cards. However, I find it hard to believe that removing a single LS323 would magically not load the PSU anymore. But it's a possibility that I can't rule out, I just don't have 2 Apple PSUs. (I did recap my PSU.)
Some people noticed the lines always come right in the middle of the characters on the screen, which would indicate a 1Mhz problem. The lines do not move or flicker.
Any advice or pointers appreciated.
I've got this Apple II europlus on my bench since months.
After a difficult repair it's now working as it should, however I can't solve what seems to be the last problem with it.
The display (may it be CRT or LCD) displays thin vertical lines, ranging from barely visible (when there are not additional cards on the expansion slots) to super bright visible (with 4 or more cards)
When I talked about my problem, new people joined my thread on AppleFritters ; this problem seems to affect half a dozen of people, but we're not making progress.
It's up to the point I can see this same issue even on A2 Europlus for sale on Ebay.
This seems to be widespread. And difficult to debug, beeing a subniche ( Apple II -> PAL monochrome )
Indeed, I have the feeling this problem is europlus specific (I don't think it affects NTSC)
I spent a lot of time trying to switch ICs (on the clock mainly), probe the bus, etc...
All I can say for sure is this appears when you add cards in the slots, and the more you add, the worse it becomes.
The two first pictures show my own A2 with one, then 4, cards added.
Interestingly : sometimes, removing a single chip out of a card (eg remove the LS323 on the Disk II card) makes the problem disappear.
This problem is NOT related to floppies. It really appears when you add a WORKING expansion card.
It disappears if you remove a single critical chip out of an expansion card (enough to make it inoperative).
I can't swap the PSU (but other AppleFritters forum says they did, with no luck). I have seen more noise on the 5V rail the more I add cards. However, I find it hard to believe that removing a single LS323 would magically not load the PSU anymore. But it's a possibility that I can't rule out, I just don't have 2 Apple PSUs. (I did recap my PSU.)
Some people noticed the lines always come right in the middle of the characters on the screen, which would indicate a 1Mhz problem. The lines do not move or flicker.
Any advice or pointers appreciated.
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