Author Topic: Williams Display Board (D11232-2)  (Read 854 times)

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Offline MartyJ

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Re: Williams Display Board (D11232-2)
« on: December 07, 2008, 08:31:08 PM »
Hi mate,

Seems the previous thread got lost in the ether,

but pin6 and pin 7 on U16 are inputs from the address bus from either U8, U9,U10, these are fed from connector J3, didnt we have a zero signal from here somewhere?

I was getting some strange readings from U7 to U11, so I replaced / socketed the lot.  I have a bit of an anomoly with Clay's guide for testing the 4049's.  Red to pin 8, black on 2-7, 9-12, 14-15.  On mine, U7, U9, U10, U11, U12 and two new ones are all getting null readings on pin 9.  However, on U8, I'm getting a reading?????

**Scratch that re U8.  Pulled out the chip and getting same reading.  Replaced it with another and now they are all the same....But still pin 6 on U16 null....Could this be a bad UDN?
« Last Edit: December 07, 2008, 08:39:18 PM by MartyJ »