Re: Fixing my 1977 (Rev 0) apple ][

["Allen Bong" <allenbsf6502@yahoo.com>]

Is this a 48K Apple (ie C D & E rows are filled up with 4116 DRAM)?

If true, then it might be one of the DRAM chip in Zero Page ($0000 -
$00FF) is bad.  You can swap one DRAM at a time from C3 to E3. Then
switch it on to see if it works by pressing "RESET".  If no then switch
off and try changing C4 to E4 and repeat until C10 with E10.

The power supply is probably OK as you can get some random characters
from the bottom part of the screen.  But if you have a volt meter, it
is better to confirm that the + and - 12 and -5 are there.

Repairing Apple II is not that hard as all the chips are socketed.  All
the chips are available from parts stores.  You can even get a used A2
board from eBay for $9.90-$12.00.

Until then, I wish you plenty of luck!

Regards and Merry Christmas

Allen Bong