Strange vertical Lines on Macintosh SE/30

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Joined: Dec 4 2012
Posts: 2

Hello everybody, i'm new on applefritter. I'have bought a Macintosh SE/30 on ebay but the mac was DOA. After a long discussion with the seller i have made up my mind to fix the little Macintosh! So i have cleaned the board, replaced all capacitors, change the RAM Modules but one problem is still there. I have vertical lines over the hole screen ( see image attached ) and i can not figure out where the problem is. Is there anybody out there where can solve this problem?

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speedyG's picture
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Joined: Nov 16 2011
Posts: 2406
Re: Strange vertical Lines on Macintosh SE/30

1 Bit of the Byte ( D0 to D7 ) is dead... this can be either the char-Rom-( a bent leg ) or the bus transiever ( damaged or bent leg ) or the RAM of the Videosection itself ( also damaged contact in SIMM-socket or damaged SIMM ).....
if oscilloscope is availiable trace D0 to D7 ... one of that lines is fixed and not transmitting information
sincerly speedyG

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Joined: Dec 4 2012
Posts: 2
Re: Strange vertical Lines on Macintosh SE/30

Hi SpeedyG Thank for the Information. Do you know where i can find circuit plans? Oscilloscope is available but how would i know on wich chip i must meter Smile

speedyG's picture
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Joined: Nov 16 2011
Posts: 2406
Re: Strange vertical Lines on Macintosh SE/30

Hello ITnetX,
i can´t call myself a MAC-expert... i only have a G3...
but i am expert on Apple II series computers ( from II till IIGS ) of which i have rhe entire line....
and the similar mistake happens occasionaly also at Computers of the II series with same cause and same result....
I´m sorry, but i only have the circuitplans from the computers of the Apple II series...
My advice would be to search here the old threads in the related forums with the search command....
second i would search for contact to local MAC-usergroups.... or find them by google.... and search their sites ... third but most frustrating will be the direct search in google clicking hundreds of useless links, till you find the one that really helps... hint...: the better the keyword search ( in the advanced search ) the less links listed ( the amount of hits is displayed in top left area ) the better.... try to get the amount of hits to less than 1000 if you want to get a chance of succeding...
sincerly speedyG

__________________

In early days I had a lot of money but no time - now I have no money but a lot of time....
the second part includes less friends but a lot more joy on life....