[comp.sys.amiga.hardware] WHICH 1084 Fix?

xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) (08/13/90)

In article <1179@tardis.Tymnet.COM> jms@tardis.Tymnet.COM (Joe Smith) writes:
>In article <8015@jarthur.Claremont.EDU> bgribble@jarthur.Claremont.EDU (Bill Gribble) writes:
>>I have a C2002 monitor on my A500 which is apparently subject to the 
>>  well-discussed 1084 popping effect.  There is one difference, though:
>>  when the monitor pops, it turns itself off.
>
>My A2002 turned itself off once after snapping.  After about the 20th "snap!",
>I went in and applied the 1084 fix to it.  No more popping.

WHICH 1084 fix?  I've seen one fix discription that attributes
the problem to a metal tab (under part of the hardware)
allowing arcing between components, and suggesting cutting
off/grinding off the tab and cleaning arc sputter residue from
the area, and another description that attributes the problem
to lack of a ground path to discharge accumulated ambient
static charge where the arcing is occurring, and suggesting as
a fix installing a ground strap to short the two modules
together and to ground.

(Please forgive that these descriptions are not very precise,
I'm going from memory.)

While it is possible for both these to be true, applying the
second "fix" with (lots of electronic repair experience but)
no knowledge of the circuitry has scared me enough to keep me
from even opening the cases on my two popping 1084s (one for
A1000, one for A2000) to fix a problem that has been occurring
for five years now in the case of my A1000 system.

And I still think Commodore should issue a recall for _all_
the monitors subject to these problems and fix them at their
own expense.  It is an obvious, widely reported problem due
to a design flaw, and they should demonstrate a little
commercial responsibility and loyalty to their customers and
FIX THEIR MISTAKES.  Cheerfully, and without the thousands of
nagging articles reporting the problem.

I am dumbfounded that CBM managed to release the 2002 series
of monitors without fixing the problem at the design level.
They had, after all, years of reports on the net and in the
trade press reporting the problem.  Why didn't they fix it
(or insist their source of monitors fix it if they purchase
Amiga monitors ready made), rather than foist another
generation of faulty hardware off on their customer base?

That wasa another great way to convince the business world
to treat Commodore and the systems it offers for sale as a
two punchline joke, and thus to stay away in droves, guys.

Are CBM convinced all of the folks on the net reporting the
problem for years before the 2002 was released were lying
just for the fun of posting yet another dig at Commodore?

IS ANYBODY LISTENING, CBM?  Do you care what the reputation
this kind of stupidity earns you does for your sales?

Kent, the man from xanth.
<xanthian@Zorch.SF-Bay.ORG> <xanthian@well.sf.ca.us>

jms@tardis.Tymnet.COM (Joe Smith) (08/26/90)

In article <1990Aug13.111924.563@zorch.SF-Bay.ORG> xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) writes:
>In article <1179@tardis.Tymnet.COM> jms@tardis.Tymnet.COM (Joe Smith) writes:
>>My A2002 turned itself off once after snapping.  After about the 20th "snap!",
>>I went in and applied the 1084 fix to it.  No more popping.
>
>WHICH 1084 fix?  I've seen one fix discription that attributes
>the problem to a metal tab (under part of the hardware)
>allowing arcing between components, and suggesting cutting
>off/grinding off the tab and cleaning arc sputter residue from
>the area

That attacks the symptom, but not the cause of the problem.

> and another description that attributes the problem to lack of a ground
>path to discharge accumulated ambient static charge where the arcing is
>occurring, and suggesting as a fix installing a ground strap to short
>the two modules together and to ground.

The heat sink needs to be grounded.  A simple ohm-meter check shows that
it is not electrically connected to anything, but it should be.

>And I still think Commodore should issue a recall for _all_
>the monitors subject to these problems and fix them at their own expense.

You mean, RCA should issue a recall.  The A2002 monitor appears to be an
off-the-shelf component with a custom logo.

>I am dumbfounded that CBM managed to release the 2002 series
>of monitors without fixing the problem at the design level.

You should blame the manufacturer, not CBM.

[Items about jokes and stupidity deleted.]

Newsgroups: comp.sys.amiga.hardware
Subject: Re: Monitor popping
Summary: Connect the heat sink to ground
Keywords: 2002, popping, snapping, etc
Message-ID: <1105@tardis.Tymnet.COM>
Date: 19 May 90 03:29:02 GMT
References: <10630@sdcc6.ucsd.edu>
Reply-To: jms@tardis.Tymnet.COM (Joe Smith)
Organization: BT Tymnet, San Jose, CA
Lines: 29

Take off the cover of the 2002 and look at it from the back.  Examine the
printed-circuit (PC) board.  To the left you should find the power connector,
the audio connector, and the chroma/luma video connectors.  That corner of the
PC board is grounded and shielded by a piece of metal that is soldered on.

To the right you should find an "L" shaped aluminum heat sink with a power
transistor bolted to the right-hand side.  (The planes of the heat sink are
vertical and surround the flyback transformer.  A thick red wire comes out
of the flyback transformer and connects to the upper side of the picture
tube.)

If you look under the printed circuit board, you should see two screws
holding the heat sink to the PC board, and a bent metal tang that goes
through a hole and also holds the heat sink down.  I saw evidence of an
electrostatic discharge that jumped from the metal tang to one of the copper
traces on the PC board.  This is the cause of the "snap" and "pop".
The heat sink is not electrically connected to anything, and accumulated
an electrostatic charge until it arced over.

I simply ran a wire from one of the screws that holds the heat sink to the
PC board over to a screw by the input connectors.  Make sure the wire is
insulated so as to not short out anything else on the PC board.  I used
an ohm-meter and verified that it showed zero ohms between the heat sink
and the grounding shield.  "Poof", no more pops!
-- 
Joe Smith (408)922-6220 | SMTP: jms@tardis.tymnet.com or jms@gemini.tymnet.com
BT Tymnet Tech Services | UUCP: ...!{ames,pyramid}!oliveb!tymix!tardis!jms
PO Box 49019, MS-C51    | BIX: smithjoe | 12 PDP-10s still running! "POPJ P,"
San Jose, CA 95161-9019 | humorous dislaimer: "My Amiga speaks for me."

xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) (08/27/90)

jms@tardis.Tymnet.COM (Joe Smith) writes:
> xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) writes:

First, Joe, thanks for republishing the fix info for this problem, and the
clarification of which fix/why that fix is appropriate.

>>And I still think Commodore should issue a recall for _all_
>>the monitors subject to these problems and fix them at their own expense.

>You mean, RCA should issue a recall.  The A2002 monitor appears to be an
>off-the-shelf component with a custom logo.

No, I bought the monitor from an Amiga dealership, it came from Commodore,
whose responsibility it was to do quality control on the item before buying
it in bulk from the original manufacturer and selling it as part of the
Amiga systems.  RCA may have built a bad monitor, but the fix is definitely
Commodore's responsibility, they failed to sell a defect free product.

>>I am dumbfounded that CBM managed to release the 2002 series
>>of monitors without fixing the problem at the design level.

>You should blame the manufacturer, not CBM.

No, the blame here is again Commodore's and by this point they were being
completely irresponsible.  Buying anything in bulk gives a company the
right to insist that it be properly made.  Commodore knew the monitor
series had a problem that eventually kills the whole system, yet continued
to purchase and sell these monitors without having the design flaw corrected,
when the cause and cure for the problem had been repeatedly published in the
trade press and on USENet.  That shows total contempt for customers, and is
unforgivable.

I still insist Commodore owes us all a recall on these monitors; asking the
naive user to fix ultra high voltage equipment, or to pay outrageous shop
repair fees for a problem entirely Commodore's responsibility is despicable.

The affect on Commodore's reputation in the user community of this continued
stonewalling on accepting responsibility is part and parcel of the problems
Commodore has marketing the Amiga, and until Commodore wakes up, things
won't improve, and they will keep posting losses.

This isn't the only problem Commodore has given this approach, by the way.
The garbage power supplies on the original A500s got similar treatment,
and for all I know are still being sold to this date.

Kent, the man from xanth.
<xanthian@Zorch.SF-Bay.ORG> <xanthian@well.sf.ca.us>

dzenc@gnu.ai.mit.edu (Dan Zenchelsky) (08/27/90)

In article <1990Aug26.184107.1217@zorch.SF-Bay.ORG> xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) writes:
>
>I still insist Commodore owes us all a recall on these monitors; asking the
>naive user to fix ultra high voltage equipment, or to pay outrageous shop
>repair fees for a problem entirely Commodore's responsibility is despicable.
>
>This isn't the only problem Commodore has given this approach, by the way.
>The garbage power supplies on the original A500s got similar treatment,
>and for all I know are still being sold to this date.
>
  Nope, the power supplies were fixed.  I replaced mine (along with the rest
of my system) when my 2002 killed it, and the new one works great (the 2002
still doesn't, however, so I don't use it)...  It's much lighter than
the origianl power supply, so if you have a lightweight one, you're 
probably o.k.
 
-Dan

>Kent, the man from xanth.
><xanthian@Zorch.SF-Bay.ORG> <xanthian@well.sf.ca.us>


--
 ___________________________________________________________________________
|  _______                         |________________________________________|
| ||    |o|     Dan Zenchelsky     |                                        |
| ||____| |                        |    Any sufficiently advanced bug is    |
| |  ___  |  dzenc@gnu.ai.mit.edu  |    indistinguishable from a feature.   |
| |_|___|_|                        |______________-- Rich Kulawiec__________|
|__________________________________|________________________________________|

BAXTER_A@wehi.dn.mu.oz (08/30/90)

In article <1195@tardis.Tymnet.COM>, jms@tardis.Tymnet.COM (Joe Smith) writes:
> 
> I simply ran a wire from one of the screws that holds the heat sink to the
> PC board over to a screw by the input connectors.  Make sure the wire is
> insulated so as to not short out anything else on the PC board.  I used
> an ohm-meter and verified that it showed zero ohms between the heat sink
> and the grounding shield.  "Poof", no more pops!

Is this the same problem as the one I have:

The aspect ratio of my 1084 alters momentarily. It's a new problem, mildly
annoying, lasts about 1 sec, and is sometimes associated with a buzzt 
noise. Could this be charge building up and deflecting the electron gun?

Regards Alan