On 8/30/2010 5:23 AM, A2Aviator wrote:
There's a back issue of Juiced.GS that I covered this in.. and I'm
still convinced that the OEM power supply is just fine for all of it.
There is an inherent weakness in the assembly of the IIgs. All that
grounding is basically returned through two wires and that power
supply connector corrodes. Taking the connector on and off a few times
every so often helps that not happen, but if you see your connector
browning near the front edge (black/ground wires) you really need to
clean it off, on both portions which means popping the pins out of the
connector and re-tensioning them, cleaning it off with a scribe or
wire brush, etc.
Checked the grounds today. There was no *visible* corrosion, but I
cleaned them anyway. Would contact cleaner and a dab of dielectric
grease be a good idea on this connector? It seems to have worked wonders
on my old German car of the same vintage as the IIgs.
IF you notice subtle intensity shifts in the image on the monitor when
you insert a disk .. this is probably why. Bad connections make the
thing work harder, and harder means more heat - a vicious circle.
I don't see any of this while inserting disks, monitor is steady. The
only thing of concern is that my power supply makes high pitched buzzing
noises. The buzzing noises change in speed during disk accesses and
video updates, similar to what I hear on a lot of cheaper laptops when
they are plugged into the A/C adapter. Many describe it as hearing the
computer "think". I also got the same interference through my poorly
shielded SoundMeister card when I had it installed. This noise isn't new
either, its been present since I bought the machine back in 1998.
I did further testing with system stability. Turning off the TWGS and
running the system at 2.8Mhz seems to be stable with no issues locking
up. I left the machine on with the cover off for 45 minutes doing
various tasks to heat everything up nice and good (power supply was warm
to touch, GALs on TWGS were very hot). Within seconds of turning the
TWGS back on the machine locked up, I couldn't even get out of the
control panel. I'm going to dig up some of the slower crystals I have
and start testing. Chances are my TWGS isn't up to the task of 12Mhz
without a better power source and some active cooling beyond the System
Saver.