Re: Tech: Wells Gardner question (in Tempest)

Rodger Boots wrote:
>
> Certainly sounds like a board problem.
>
> If you have a scope just look at the X & Y outputs on the board. They
> should swing both positive and negative.
>
> Don't have a scope? Use a volunteer. Each output should read near
> zero volts, NOT a volt or so one polarity or another.
>
> Don't have a meter? DUDE!!!
>

"Use a volunteer."? That's interesting - I always figured the swing on
the board test points was only a couple of volts AC and thus unlikely to
ruffle even the most sensitive volunteer...

Now I have used my own tongue to check if a 9V battery is good - can you
determine AC/DC that way too? Knowing more will help in those situations
where I have forgotten to take my voltmeter on a repair job...and have a
spare person about.

John :-#)#
>
>> On Aug 29, 2010 10:48 PM, "Ty Roden" <ty.roden@gmail.com
>> <mailto:ty.roden@gmail.com>> wrote:
>>
>> I have a Wells 19K6100 monitor inside my Tempest machine that is
>> exhibiting odd behavior. I hope someone has seen this before and has
>> a few directions I can check that may resolve the issue.
>>
>> The machine fires up and shows the game running - but in the lower
>> half of the screen. This is not like what I would expect for a
>> deflection issue, as the whole screen is fine, nothing missing - just
>> all within the lower half of the display. The game is fully playable
>> like this. I initially thought this was somehow related to the
>> deflection circuit, so I began by checking the Y amp circuit on the
>> P314 deflection board. Other than a few wires barely holding on
>> (which I fully resoldered correctly) there were no issues. All
>> transistors and seemingly all voltages are fine. Every once in a
>> while the spotkiller will kick on briefly - then disengage and
>> continue showing the game.
>>
>> I am starting to think that the deflection board is actually fine -
>> and that the game board may be sending lower than expected signals? I
>> have found nothing that helps to explain the expected input to the
>> monitor.
>>
>> Any ideas on where else I can double check this to narrow this down?
>>
>> Thank you for any assistance.
>>
>> -Ty Roden
>>
>>

-- 
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"
---------------------------------------------------------------------------
** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
** Please direct other questions, comments, or problems to chris@westnet.com