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Tech: Williams System 11 score displays

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Greenacarina

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Nov 21, 2009, 1:51:53 AM11/21/09
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Still fighting with my displays on F-14 Tomcat. Following Clay's guide and
testing my 4049's (as my current symptoms would indicate these may be the
problem)....U9 and U10 each had some pins that tested bad. These are labeled
"TC4050BP" which Mouser lists as obsolete. What is an acceptable substitute?
Also, is there a tech guide somewhere that explains specifically how these
displays work (which chips do what....my U1 also has 1 pin that test bad,
but I don't know what it's function is). Steve Kulpa has an excellent page
that explains Bally displays and I was hoping someone had similar info
regarding the Williams displays.

Thanks.
Chris

GPE

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Nov 21, 2009, 2:27:25 AM11/21/09
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"Greenacarina" <greena...@verizon.net> wrote in message
news:he82m5$7be$1...@news.eternal-september.org...

TC4050BP's = standard 4050's.
Those are just plain jane logic buffers -- signal out = signal in.
Pin 1 = VCC (power)
Pin 2 = output, buffered version of input pin 3
Pin 4 = output, buffered version of input pin 5
Pin 6 = output, buffered version of input pin 7
Pin 8 = ground
Pin 10 = output, buffered version of input pin 9
Pin 12 = output, buffered version of input pin 11
Pin 13 = nconnect
Pin 15 = output, buffered version of input pin 14
Pin 16 = no connect

Ed


John Wart, jr

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Nov 21, 2009, 2:40:41 PM11/21/09
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I could be mistaken, aren't 4049s and 4050s different? I thought I read
somewhere that some schematics had the part numbers mixed up?

"GPE" <GPE_N...@Cox.net> wrote in message
news:yDMNm.6722$cX4....@newsfe10.iad...

GPE

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Nov 21, 2009, 3:14:45 PM11/21/09
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Yep, they are different.
4050's are straight buffers.
4049's are inverting buffers.

Chris said he had TC4050BP's in the original board -- those are Toshiba
4050's.
I have never taken the time to see what is supposed to be in that game. I
thought they were 4049's but without actually seeing it - I don't know.

Ed


"John Wart, jr" <johnw...@johnwartjr.com> wrote in message
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Greenacarina

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Nov 21, 2009, 3:23:54 PM11/21/09
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Exactly, that's one of the things that had me confused. Read that the
schematics are mis-labeled....but wanted to make sure that I shouldn't be
replacing what's labeled "4050" with "4049" (sounds like I'm sticking with
"4050").
Now the biggie is trying to find a replacement for the UDN7180 that appears
to be toast at U15 (and would this test "bad" if I have the 2 4050's removed
at U9 and U10????)

Thanks.
Chris

"John Wart, jr" <johnw...@johnwartjr.com> wrote in message
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