Re: Req: Help with a sick IIC !!!

[eeastman@NOSPAMappple2.com]

Jan:
Two things to check, valid IIc boot disk and power.  Try borrowing a good
IIc form a user in your area and try using their power supply on your IIc,
try one of their know good boot disks on your IIcs.

You said you tried the disks on a IIe, are these boot disks ones that would
work on a IIc?  I know alot of older stuff will not boot on a IIc because of
the boot rom.  Of course the prodos thing confuses me because ProDOS of any
variety _should_ work on a IIc.

So are you using the same power supply on all these failing IIcs?  Try a
different power supply.

What pwoer frequency do you have in VIP.FI? (Your e-mail domain.)  Do you
have a power supply built for your part of the world?  50Hz AC power
generates a different voltage when rectified into DC, and may cause problems
with filtering capactitors.  A different frequecy will totally screw up the
rectifier and will produce AC laden (unstable DC) and lower current capacity
and higher voltage.

Since you solder, I assume you have a VOM, check the voltages inside the IIc
at the memory chips, make sure it is high enough.  Watch for a voltage drop
when you activate the drive.  If you have access to an osilloscope, check
the AC component of your DC voltages and see if there is a frequency riding
your DC that may be causing problems in your ram.

These are the only things I can think to check since all of your IIcs appear
to be having the same problems.

Thankx,
Ed

Jan wrote:

> Yes, I tried three different disk drives,and I tested the boot floppies
> on my 2E.  On PRODOS I get "Unable to load PRODOS" and on DOS33, I�ll get
> the Hex or assembler message.