>> that the pin sticking thru the back side would have a blob of solder
>> around it that would have a crack in it, and possibly be seperated from
>> the board. If I remember right, it was a red cable in a group of cables,
>> located kind of in the center of the board.
>
>In the middle of the board there's J4, which is the cable to the logic
>board. I've never had dry joints there.
Yes, J4 is what I was thinking of here. This is the one that commonly
cracked, and carried the smack the case repair tip from Apple. I am
amazed you haven't seen it go, I think every Mac Plus I repaired had
signs of that joint having been overheating and arcing (one was so bad,
the PCB was eaten out around the connector, and the insulating cover had
a hole burned thru it). Most were cracked and needed to be resolded. Of
course, mine all would have looked worse, as for quite some time, they
were all treated with the case smacking... and many of the staff didn't
understand to hit it gently, to jar the connection, not punch it to knock
the mac off the desk (I started doing repairs when I came in one day to
hear a chorus of *SMACK* &#_at_&$(@#&*# *SMACK* going up and down the
halls... but back then I was part time, so things had to get pretty bad
before anyone called me to come in)
>> The final common problem was a bad diode near the bottom of the board.
>
>The component reference for that would be interesting. Maybe one of CR21,
>CR20, CR26 (recitifer diodes for the 3 main supply lines)?
The one I was thinking of is CR20. (I am almost positive that is the one,
I have to base it off my notes unless I am going to actually open one of
the repaired macs and have a look)
-chris
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Received on Thu Oct 25 2001 - 16:58:42 BST