[ukvac] Re: TECH : Battlezone troubles... continued..
At 05:16 PM 2/29/00 -0800, you wrote:
>hi all..
>
>OK, if you're getting tired of hearing about my continued troubles then skip
>this message now... otherwise, please read on
It gets a bit involved at
>this point in the repair, so have the schematics sheet handy (battlezone
>schematics sheet 2, side B)
>
>OK, following the advice of Chad at the last meeting, i decided to replace
>the 74s74 at location J10. This is because i traced the z blank signal as
>far back as here, LOW at all times. Now, the 7474 is recieving inputs
>correctly (DVY 8 at pin 12, and LATCH1 on pin 11),
Pin 11 should be a clock sig not latch1.
sounds as if the 74/74 is not clocking trace back NOT stat clk
on pin 4 of K10
hope this helps
Pete (Invadar)
but it's output at pin 9
>is still LOW. I don't know exactly what else it needs to output correctly at
>pin 9, i don't really understand the logic involved in its entirety.. now, i
>understand that it's a dual-type flip-flop, and the SET/RESET lines (coming
>in from pin 10 and 13) obviously make the whole thing tick.. They are both
>HIGH at all times..
>
>My problem is, i've replaced the 7474 and i'm getting the same results,
>there isn't (seemingly) a problem with the inputs on pins 11 and 12, but the
>set/reset lines on pins 10 and 13 are a worry, they're high at all times,
>should they be doing something else?
>
>the schematics show them both as P,R67 does this mean they've just been tied
>high from a resistor?
>
>so anyhow, i'm back to square one, i hoped that the replacement of the 7474
>would sort it out, alas, as we all know, hoping for a quick fix never works
>
>
>I also had to go to Maplins and buy a new soldering iron as i was unable to
>get heat right where i wanted when removing the chip, i picked up a baby
>ANTEX soldering iron with a pinpoint tip for 15 quid, and blimey i'm
>extremely impressed!
>
>anyhow, any help is much appreciated!
>
>
>seeya!
>
>=============================================
>Andy Welburn - Collector Of Fine Video Game Antiquities
>http://www.willowsp.u-net.com/andy/
> >>>> CURRENTLY MOST WANTED <<<<
> WORKING Atari Asteroids Boardset
>==============================================
>
>
>------------------------------------------------------------------------
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At 05:16 PM 2/29/00 -0800, you wrote:
>hi all..
>
>OK, if you're getting tired of hearing about my continued troubles then skip
>this message now... otherwise, please read on
It gets a bit involved at >this point in the repair, so have the schematics sheet handy
(battlezone >schematics sheet 2, side B)
>
>OK, following the advice of Chad at the last meeting, i decided to replace
>the 74s74 at location J10. This is because i traced the z blank signal as
>far back as here, LOW at all times. Now, the 7474 is recieving inputs
>correctly (DVY 8 at pin 12, and LATCH1 on pin 11),
Pin 11 should be a clock sig not latch1.
sounds as if the 74/74 is not clocking trace back NOT stat clk
on pin 4 of K10
hope this helps
Pete (Invadar)
but it's output at pin 9
>is still LOW. I don't know exactly what else it needs to output correctly at
>pin 9, i don't really understand the logic involved in its entirety.. now, i
>understand that it's a dual-type flip-flop, and the SET/RESET lines (coming
>in from pin 10 and 13) obviously make the whole thing tick.. They are both
>HIGH at all times..
>
>My problem is, i've replaced the 7474 and i'm getting the same results,
>there isn't (seemingly) a problem with the inputs on pins 11 and 12, but the
>set/reset lines on pins 10 and 13 are a worry, they're high at all times,
>should they be doing something else?
>
>the schematics show them both as P,R67 does this mean they've just been tied
>high from a resistor?
>
>so anyhow, i'm back to square one, i hoped that the replacement of the 7474
>would sort it out, alas, as we all know, hoping for a quick fix never works
>
>
>I also had to go to Maplins and buy a new soldering iron as i was unable to
>get heat right where i wanted when removing the chip, i picked up a baby
>ANTEX soldering iron with a pinpoint tip for 15 quid, and blimey i'm
>extremely impressed!
>
>anyhow, any help is much appreciated!
>
>
>seeya!
>
>=============================================
>Andy Welburn - Collector Of Fine Video Game Antiquities
>http://www.willowsp.u-net.com/andy/
> >>>> CURRENTLY MOST WANTED <<<<
> WORKING Atari Asteroids Boardset
>==============================================
>
>
>------------------------------------------------------------------------
>Get what you deserve with NextCard Visa! ZERO! Rates as low as
>0.0% Intro APR, online balance transfers, Rewards Points, no
>hidden fees, and much more! Get NextCard today and get the credit
>you deserve! Apply now! Get your NextCard Visa at:
>http://click.egroups.com/1/970/5/_/5935/_/951844926/
>
>-- Create a poll/survey for your group!
>-- http://www.egroups.com/vote?listname=ukvac&m=1
>
>
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Get what you deserve with NextCard Visa! Rates as low as 2.9%
Intro or 9.9% Fixed APR, online balance transfers, Rewards Points,
no hidden fees, and much more! Get NextCard today and get the
credit you deserve! Apply now! Get your NextCard Visa at:
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-- 20 megs of disk space in your group's Document Vault
-- http://www.egroups.com/docvault/ukvac/?m=1