Re: Apple II Minus Question

["Bryan Parkoff" <bryan.nospam.parkoff@nospam.com>]

Bill,
> So, therefore, if Bryan is starting up and
> no monitor prompt comes up on RESET, then
> the CPU is probably at fault, but since it
> works in another board, then the fault is
> a trace on the 5v line somewhere. This is
> provided the RESET key is working at all.
> I wonder now if he has tested the keyboard
> on another motherboard.
    Yes, I have tested three keyboards to another working Apple II
motherboard.  They are functioning fine.

    I give you an example.  GR and HGR are not working on second motherboard
while Old Monitor Routine is not powered up on first motherboard.  I tried
to swap ALL 74xxxx and DRAM chips from working motherboard to both defective
motherboards.  The status is still the same.  There is no solution for Old
Monitor Routine Start-Up and GR & HGR working.

    I must admit that it is necessary for me to purchase electronic
diagnostic equipment to test three defective motherboards.  I still have
voltimeter.  Is it worth to obtain several different diagnostic tools?

--
Bryan Parkoff