Re: OK first real Mac Complaint - Network Trouble

Tom Watt <tom@xxxxxxxxxxxxxxxx> wrote:

OK I am beginning to suspect possible hardware problem here. Although
changing the channel on my router has cleared up wireless issues on my
entire network, I still have a lot of trouble accessing the Mac and
have to reset it when the connection dies. I am suspecting a real lock
up.

Have you tried connecting a keyboard, mouse and screen on the computer
to see what it is doing when it appears to have locked up? Perhaps the
VNC server process has just stopped for some reason, and the rest of the
computer is running fine. Another option might be to enable Remote Login
and use an SSH client on another computer to connect to it, then use the
command line tools to investigate what has happened.

If it really is locking up in some way, then question is how? Is it a
kernel panic or just something occupying all the CPU time? Have you had
a look in the console log (/Applications/Utilities/Console.app) to see
if anything strange is being reported?

The problem might be related in some way to the use of VNC. Perhaps
while a download is in progress, something is causing the VNC connection
to suck up a large amount of network bandwidth to do unnecessary screen
refreshes.

Using a network traffic analyser of some kind might provide some clues
as to what is going on. It should at least help to identify what the Mac
is doing to tie up the network, and where it is sending data.

The hard drive was loose inside when I got this thing.. And when I
formatted it it formatted very fast. I assume it did not check every
sector of the hard drive during format.

That's normal. The hard disk is assumed to be working, or if it has an
occasional bad sector it will be automatically spared out by the drive
when first written to. I don't think Mac OS handles a failed drive (with
unfixable bad sectors) very well. Disk Utility should at least alert you
to the problem, as long as the computer and drive can report the SMART
status.

Is there a built in utility that will do a complete surface scan of the
drive?

Nothing occurs to me. I use TechTool Pro to do disk hardware tests.

Some Mac models were supplied with a Hardware Test CD, but I haven't
used it for ages and I don't recall if it does a hard drive surface
scan.

I'd also like to test the memory. If there is any other diagnostics I
can run that might be a good idea too. Any suggestions?

Not built in. The Hardware Test CD is one option, if you have it.

TechTool Pro also does a memory test, but I don't trust it as it is just
a simple data pattern test which probably would spot addressing faults.
(The old versions offered much more comprehensive tests.)

There was quite a good little memory test program which ran under Mac OS
9, called RAMometer. It got incorporated into a freeware program called
"Gauge Pro", from Newer Technology. To use this, you would have to boot
directly into Mac OS 9, and preferably disable virtual memory.

There might be a command line tool which can be used when booting the
computer into single-user mode, but I haven't gone looking for anything.

Tom Watt wrote:
OK this is the first show stopping problem. If I can't get this fixed
bye-bye Mac.

I was downloading updates on our 256Kbps DSL line and it made the rest
of the network unbearably slow. This seems to be consistant. Whenever
I am downloading anything it seems to steal all the bandwidth. And we
will loose wireless connectivity and when I get back online I can only
access the Mac again by resetting it with the reset button. (it has no
keyboard, mouse, or monitor attached, I use it strictly via VNC on my
PC laptop). I have to go reset it now for maybe the 4th time today. I
thought it was the AirStation wireless adaptor I was using, but I
connected it via Ethernet directly to the router after that and it
still is doing the same thing.

Any ideas before I give it the boot? It's a PowerMac G4 450mhz with
1GB RAM btw.


--
David Empson
dempson@xxxxxxxxxxxxx
.