RE: Question on ELMINATOR SOUND CARD with NO AUDIO Output and X/Y Output.....

Doesn't the sound board have an opamp that the output is derived from...
maybe the op-amp is toast... I've had this happen on an Atari game board
(static blew it while cleaning the edge connector). If you have a scope
look at the input and the ouptut... if you have a good waveform on the
input, but noise on the output it's the opamp.

-- Curt

>From: Stempak Arcadius-ASTEMPA1 <ASTEMPA1@motorola.com>
>To: "'vectorlist@synthcom.com'" <vectorlist@synthcom.com>
>Cc: Stempak Arcadius-ASTEMPA1 <ASTEMPA1@motorola.com>
>Subject: RE: VECTOR: Question on ELMINATOR SOUND CARD with NO AUDIO Output and
X/Y Output.....
>Date: Tue, 1 Oct 2002 17:30:53 -0500
>MIME-Version: 1.0
>
>Mark,
>^^^^^
>
> One other thing which comes to mind,
>and again this may or may not be important,
>but when I initially hooked up the Output
>from this Sound Board I may have, at least
>initially crossed the GND and SOUND OUT from the
>Sound Board into the G-80 Power Supply (AMP)
>
> Now I know that the AMP WORKS just fine,
>as I have tested it, but now wonder if, when I
>did the above I blew something on this Sound Board ???
>
>
> Thanks..........
>Arcadius............. :-)
>
>-----Original Message-----
>From: Stempak Arcadius-ASTEMPA1
>Sent: Tuesday, October 01, 2002 5:27 PM
>To: 'vectorlist@synthcom.com'
>Cc: Stempak Arcadius-ASTEMPA1
>Subject: RE: VECTOR: Question on ELMINATOR SOUND CARD with NO AUDIO
>Output and X/Y Output.....
>
>
>Mark,
>*****
>
> O.K. Thank You, and as for White Noise,
>actually let me rephrase this, it's more
>like Static, if you want to call it that,
>I.E. kind of sounds like a SHHHHHHH type of noise.
>kind of the old days when you tuned your T.V. to
>a Channel Not INS (UHF CHANNEL) and saw STATIC on
>the SCREEN while also listening to this type of Noise.
>
> And again this Noise, or Sound is very
>much present the entire time I have this
>thing powered up.
>
> Could there be something wrong with one of
>the ROMS which would cause this issue ???
>
> Better yet do you know Which Number ROMS
>actually Store (Contain) the Sound Code ???
>
> Also verified the Backplane and it's All Clean.
>In addition blew out All of the DUST and checked
>every connector.
>
>
> Thanks.....for all of your assistance....
>Appreciate it........
>
>
>Arcadius........... :-)
>-----Original Message-----
>From: Mark Jenison [mailto:jenison@enteract.com]
>Sent: Tuesday, October 01, 2002 3:49 PM
>To: vectorlist@synthcom.com
>Subject: Re: VECTOR: Question on ELMINATOR SOUND CARD with NO AUDIO
>Output and X/Y Output.....
>
>
>> I am wondering if I am doing something wrong, but what, especially
>> and even with other Boards (X/Y) REMOVED and only the CPU, ROM and SOUND
>> Board in the CAGE I still get the same (White Noise) and no audio.
>>
>> Also would like to get you input on replacing Electrolytic Caps, if
>> I recall correctly as long as the Voltage and uF are identical of greater
>> you can Sub one cap for another ??? I.E. Replace a 10uF 25Volt with a
>> 22uF 35Volt <- does that sound right ???
>
>No, but I'm not an EE. :-). I think the rule is same uF, but higher voltage
>is ok.
>
>> Finally and upon looking at the ROM BOARD itself, It only contains 14
>ROMS
>> which I believe is Normal for ELIMINATOR from U1 to U15 or something like
>> that
>> however I noted that on this Same ROM Board U29 Socket has a DM74LS245N
>> Plugged
>> into this Socket, should this part be there ???
>
>Yes, that's correct.
>
>> Just wondering as the
>> Schematics
>> make no mention of such a part on the ROM BOARD.
>
>If you are still getting white noise, normally I would still suspect the CPU
>board, or voltages to the boardset. Are you sure it's white noise, and not
>just loud "nothing"? At this point, I'd swap around known good working
>parts, but most people don't have this luxury :-). From where you're at
>now, I would start using a logic probe, but without a custom extender card,
>it's very difficult to do any probing of boards in the cage. I've heard of
>people removing the back bus from the cage and setting the cards up so they
>can access them; you may want to try that at this point.
>
>--
>Mark Jenison
>
>
>
>
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Received on Tue Oct 1 16:34:59 2002