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Macintosh SE/30 problem.
Posted by: toples50 on 2020-02-10 12:24:57
From a friend of mine who has problem with his SE/30

"Hello Guys!

I've recently owned a SE/30 .i have the squares on my screen that indicates interruption between rom and cpu. i have recapped my board using tantalum caps and problem still persists. i found another SE/30, tried the rom simm and ram and the problem is there. also ive tried my Rom Simm and ram on the working one and checks ok. finally i've found the schematics and pin by pin checked the continuity and everything seems to checked ok. Also there is no Chime sound

I am attachiing you pics of the board. As you can see, there is no leak and the board is quite clean

Id appreciate any help you could provide.

thank you in advance!"
85132114_10221735284598504_8160133529607340032_o.jpg

85160706_10221735280558403_2629065948509765632_o.jpg

85176561_10221735281638430_6931011007292637184_o.jpg

85205723_10221735284558503_1240448200750399488_o.jpg
Posted by: LaPorta on 2020-02-10 13:38:24
You sure that cap with incredibly long leads is not shorting to the chip underneath it? Also, are you sure that everything is grounded? Sometimes I've had that when I had a bad ground.
Posted by: toples50 on 2020-02-10 23:21:29
 allright guys, i found that the vram failed, so i removed it, sockets and installed spare ones. now i get horizontal stripes that after reset i have chime and blinking mouse and disk sign

84727557_10221738112629203_5910356787252428800_o.jpg
Posted by: Bolle on 2020-02-10 23:25:32
I can see Micron VRAM chips on one of the photos... no surprise they failed.

Micron memory from that time was notoriously bad.
Posted by: LaPorta on 2020-02-11 01:15:54
WHy the horizontal stripes when you fire it up, though?
Posted by: Bolle on 2020-02-11 01:25:35
WHy the horizontal stripes when you fire it up, though?
Good question.

@toples50 are you running a non-standard ROM? Some of those show stripes while the RAM check is performed.
Posted by: toples50 on 2020-02-11 01:44:42
If I make fast on/off, boots but then makes blinking.I believe its the ROM.(which is the stock ROM)
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