Re: Asteroids X axis problem

>Does your machine have the original power brick?

It sure does.

>If it was swapped in from another game, the plus/minus supply
>voltage might be too low. Also check the transformer taps used to
>set the output voltage. I have a feeling that the AC output voltage
>is running too low. The long axis is showing the limiting or
>walling effect because the deflection transistors are saturating due
>to insufficient DC power supply voltage.

The thing is that the fault doesn't appear if I use my own rev 5 PCB
- it's only this rev 2 PCB that I've just fixed which has the 'fault'.

>Be aware that a GO5-801 monitor required plus/minus 25-28 VAC power
>supply whereas the GO5-802 required 35-37 VAC. If your monitor is
>an 802 and your brick is set for an 801, that's your problem.

It's an 802 and all is set correctly. Thanks for the suggestions. :-)

Phil

>----- Original Message ----- From: <arcaderelics@irongiant.org.uk>
>To: <vectorlist@vectorlist.org>
>Sent: Thursday, March 11, 2010 5:55 PM
>Subject: Re: VECTOR: Asteroids X axis problem
>
>
>>
>>>Does the test pattern similarly degernate into a line at the edges
>>>unelss the size is reduced?
>>
>>Yeah, it kind of mashes up the diagonals as they hit the far left
>>and right edges.
>>
>>>Are your +15V & -15V good?
>>
>>Yup, no problems there.
>>
>>
>>Thanks,
>>Phil
>>
>>
>>
>>>--- On Thu, 3/11/10, arcaderelics@irongiant.org.uk
>>><arcaderelics@irongiant.org.uk> wrote:
>>>
>>> > From: arcaderelics@irongiant.org.uk <arcaderelics@irongiant.org.uk>
>>> > Subject: Re: VECTOR: Asteroids X axis problem
>>> > To: vectorlist@vectorlist.org
>>> > Date: Thursday, March 11, 2010, 1:53 PM
>>> >
>>> > > > I can't unfortunately see any faults when I
>>> > 'scope out the signals.
>>> > > When you "scope out" which signals? If the output
>>> > (X&Y) looks good, then you're looking at a monitor
>>> > problem.
>>> > >
>>> > > Either way, it sounds like a problem in one of the
>>> > analog sections (monitor or board), as in a signal
>>> > clipping.
>>> >
>>> > The 4016 has been replaced as it was faulty (total screen
>>> > collapse in the X axis) so perhaps the TL081 or TL082 ?
>>> >
>>> > Perhaps even the AD561 ?
>>> >
>>> > > If you make the picture smaller, does the "vertical
>>> > line" unfold in an object?
>>> >
>>> > Sorry, Forgot to mention - the problem goes away if the
>>> > picture is reduced to 'small to moderate' size in the X axis
>>> > - if it's between moderate to large then the fault occurs.
>>> >
>>> > > Do you have a picture?
>>> >
>>> > Afraid not, not much to see really though, just a vertical
>>> > line the height of the object as it passes through the edge
>>> > of the screen (the object is still drawn okay though).
>>> >
>>> >
>>> > Thanks,
>>> > Phil
>>> >
>>> >
>>> >
>>> > >
>>> > > -Mark
>>> > >
>>> > >
>>> > >
>>> > > Just been fixing up my first Asteroids board for ages
>>> > - multiple problems, all now fixed ......... except for
>>> > one.
>>> > >
>>> > > Whenever an object gets to the far left or right edges
>>> > of the display it's still drawn okay BUT as the object
>>> > passes through the edge it makes a vertical line at that
>>> > edge where the object is passing through - the line is same
>>> > 'height' as the object too.
>>> > >
>>> > > Now I've seen something similar before which was
>>> > caused by a problem with the UNMDACX12 signal, but in this
>>> > case that's not the problem as changing the relevant chips
>>> > (7404 at H10 and LS191 at C9) doesn't fix the fault.
>>> > >
>>> > > This is an early Rev 2 board.
>>> > >
>>> > > Could of course be the AD561 DAC, or the TL081 or
>>> > TL082 in the X axis output circuit, but is there anything
>>> > else that I've missed before I go swapping out multiple
>>> > chips? I can't unfortunately see any faults when I 'scope
>>> > out the signals.
>>> > >
>>> > >
>>> > > Thanks,
>>> > > Phil
>>> > >
>>
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Received on Fri Mar 12 05:14:40 2010