|More ST TROUBLES [message #283012]
||Wed, 12 March 1986 11:01
Originally posted by: ker|
Posted: Wed Mar 12 11:01:57 1986
Date-Received: Fri, 14-Mar-86 04:59:48 EST
Organization: AT&T Information Systems Labs, Holmdel NJ
Well, another week has gone by and I still don't have a working 520ST.
It has been in repair since January 16th.
Would you believe that I sent the computer and power supply together
along with a note stating the power supply was blown and they only
fixed the computer. They sent me back a fixed (?) 520 and the same
blown power supply. Thank goodness I checked the power supply before
plugging it into the computer.
I now have to send back the power supply and they will send back a new one.
Note, I MUST send mine back first even though I was told the old black
one will be replaced (supposedly they have a design problem that causes
+5 to go to +15V). Therefore I assume it will take another week
to get another supply, assuming they are available.
A word of advise. I have been told that if you have the old black "brick"
power supply for the 520ST (P/N CO70099-3) you can be in the same situation
as me. There is a design problem that can cause the +5 volt supply to
provide +15 volts. This extra voltage does not make the computer work
three times faster (3 X 5 = 15). It puts you in the same position
I am in. Your computer will have to take a trip to the local repair
shop for an extended vacation, hopefully not > 2 months as in my case.
The advise I've been given is to get ATARI to replace your old power
supply with the newer model. Supposedly the old supply is a disaster
waiting to happen. Again, let me emphasize I am repeating what
I was told. This is not my opinion and do not claim originality
for these claims.
|Re: More ST TROUBLES [message #283074 is a reply to message #283012]
||Wed, 19 March 1986 05:48
Registered: December 1985
Posted: Wed Mar 19 05:48:43 1986
Date-Received: Fri, 21-Mar-86 03:46:31 EST
Reply-To: knnngt@ukma.UUCP (Alan Kennington)
Organization: U of KY Mathematical Sciences
***** Nobody knows the lines I've eaten - song title *****
It's about time I make another comment on the jolly black power supplies. A
couple of days ago, my TOS ROM(s) blew. I deduced this from the fact that
all went well with the old chips replaced. It took a week for the new chips
to stop working. But I gather that these ROMs are really Eproms which happen to
be opaque, which makes them somewhat vulnerable to the dreaded power supply
Now the people who told me about the power supply scandal have consequently
informed me that a very simple test will determine whether the power supply
is of the evil variety, without having to wait for disaster to visit. It
seems that with zero load, a humble voltmeter will demonstrate the true
nature of the thing. So this would indicate that the same fault that causes
sub-optimal start-up characteristics also causes inappropriate response to
zero load. If so, this would help prevent a lot of indecision about what to
do with "the black power supplies".