Apple IIc Plus video problem

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Last seen: 1 month 2 weeks ago
Joined: Dec 21 2019 - 09:27
Posts: 1
Apple IIc Plus video problem

Hello, I recently got this apple IIc Plus. When I turn it on, the screen shows characters in red/blue color instead of white.

It sometimes shows white characters, but after a few seconds, it switches back.

How can I fix this? Please help me.

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Last seen: 1 month 3 weeks ago
Joined: Apr 24 2012 - 17:03
Posts: 261
It can be the video chip, but

It can be the video chip, but most likely is your cable or monitor brand.Is that an original Apple monitor? try another cable or monitor.

There's also a cable yoy can make to use with LCD:
https://www.youtube.com/watch?v=wQaouPzMSsI

 

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Last seen: 3 days 2 hours ago
Joined: Nov 7 2019 - 13:49
Posts: 32
RAM or logic issue

This is clearly a RAM or video logic issue. Some chip needs to be replaced. Many of the random and replaced characters indicate that bit 3 (=0x08) is stuck to 0 (this results in replacing "I" (=0x73) with "A" (=0x65), "O" (0x79) with "G" (0x71) etc.

Try to run the diagnostics and see if you're "lucky" and any RAM is defective. Otherwise you'll need to dive in deeper to investigate the video logic.

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