Re: Tempest Restoration Blog

From: William Boucher <boucher_at_mnsi.net>
Date: Sat Sep 13 2008 - 16:40:50 EDT

The card edge connector has nothing to do with the power supply to the
monitor. I have seen a bad card edge finger that causes the AVR sense
resistors to blow but I've never seen this do anything to the monitor save
for causing the game board to quit and the spot killer to come on. Granted,
when games sat in this condition for days at a time, the monitor regulator
transistors could be stressed to failure and that was common. Installing
the LV2000 will eliminate that possibility. I've never seen the frame
mounted transistors burn out do to this situation. Maybe I haven't waited
long enough or seen enough machines with the problem. I've seen 6100
monitors that had lost one side of the power supply or the other and nothing
really bad happened. I've never seen one that had lost just the ground
though so I can't speak for that failure mode. The ground for the monitor
is connected way back at the power brick, before the AVR and the game board
so anything that those boards do is really not going to effect the overall
ground level. It may make the video input signals appear to be a bit higher
voltage-wise than usual and I can see how that might skew deflection way off
to one side. The frame mounted transistors on that side might be driving
harder than usual for longer than usual so I suppose that if the condition
got bad enough and assuming the spot killer never comes on because the game
board is somehow still running, then maybe the big transistors could fail if
the condition persisted long enough. But wouldn't the player notice that
the picture was screwed up and do something about it (like turn it off)
before things flamed out?

All things considered however, I agree that you can't really have too many
grounds so adding the additional heavy leads with robust connections can
only improve things. Personally, I just repair the original connections
with new terminals/connectors/wire and things work great.

William Boucher

----- Original Message -----
From: "John Robertson" <pinball@telus.net>
To: <vectorlist@vectorlist.org>
Sent: Saturday, September 13, 2008 4:14 PM
Subject: Re: VECTOR: Tempest Restoration Blog

> William Boucher wrote:
>>
>> While none of that could really hurt anything, I have never had to do
>> this sort of thing on any Atari vector games and I own several. I think
>> you guys are confusing these 6100 monitors/games with Sega GO8 which is a
>> whole other story.
>>
>> The worst common supply problem with Atari games that have an AVR board
>> is when the either the +5V or ground edge fingers burn due to bad edge
>> connector terminals. Once the main positive or negative supply paths are
>> compromised, the 10 ohm resistors on the AVR board will burn up. It's
>> not the wires that aren't heavy enough, it's the terminals inside the
>> connectors that need replacing and the edge fingers that need fixing
>> (simple self-adhesive solderable copper tape works wonders).
>>
>> William Boucher
>>
> Indeed, this is not nearly as needed as for the GO-8s! However when the
> card edge connections start to fail this will give the common/ground shift
> that can take out the transistors on the monitor...
>
> Consider it preventative maintenance.
>
> John :-#)#
>>
>> ----- Original Message ----- From: "John Robertson" <pinball@telus.net>
>> To: <vectorlist@vectorlist.org>
>> Sent: Saturday, September 13, 2008 12:13 PM
>> Subject: Re: VECTOR: Tempest Restoration Blog
>>
>>
>>> I think the easiest route is to make a couple of solid common/ground
>>> connections - one on the logic board (bolt/solder a wire to the ground
>>> plane, a similar one on the regulator, and lastly one on the monitor
>>> chassis. These should be tied together with a separate wire - 18 gauge -
>>> with the tie point being the power supply. So you will have two wires,
>>> one from the power supply to the boards, and the second to the monitor.
>>>
>>> This should help reduce or eliminate the risk of ground/common potential
>>> voltage drift which burns out driver transistors...
>>>
>>> (Of course installing the LV2000 kit on W.G XYs is HIGHLY recommended -
>>> I do that on every Wells Gardner colour XY monitor that comes near our
>>> shop!)
>>>
>>> John :-#)#
>>>
>>> Colin Davies wrote:
>>>>
>>>> Thanks - Yes I had that in mind, but not sure how I'll aproach it yet.
>>>> I did notice the power wiring from P7 (5v out connector) looks a little
>>>> thin indeed.
>>>>
>>>> I've read this before somewhere, wasn't there an article in one of the
>>>> FAQ's (b+w one perhaps) - I'm sure your name was quoted in there.
>>>>
>>>> A friend has a issue with his starwars, the monitor keep going wrong...
>>>> I'm sure its a similar issue.
>>>>
>>>> Regards, Colin
>>>>
>>>> ----- Original Message ----- From: "John Robertson" <pinball@telus.net>
>>>> To: <vectorlist@vectorlist.org>
>>>> Sent: Friday, September 12, 2008 8:34 PM
>>>> Subject: Re: VECTOR: Tempest Restoration Blog
>>>>
>>>>
>>>>> Make sure you upgrade the common/ground connections between the loig
>>>>> boards, power supply and monitor!
>>>>>
>>>>> John :-#)#
>>>>>
>>>>> Colin Davies wrote:
>>>>>>
>>>>>> Finished the brick rebuild - Repaired, sense modded and tested an
>>>>>> ARII (not checked the audio yet) - Got good healthy voltages...
>>>>>>
>>>>>> Plugged all the looms in and the pcb, but it does not seem to be
>>>>>> doing anything at the moment (got a nice healthy 5v) - I'll need to
>>>>>> try diagnose the pcb shortly when I can make some space - might be a
>>>>>> first use of the fluke 9010a :-) - Not got any bleeps or bloops ..
>>>>>> must investigate further... Can't find my scope probes for a start !!
>>>>>>
>>>>>> Dare not plug in an XY monitor just yet....
>>>>>>
>>>>>> Cheers, Colin
>
>
> --
> John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call
> (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
> www.flippers.com "Old pinballers never die, they just flip
> out"
>
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Received on Sat Sep 13 16:40:40 2008

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