Re: Battlezone self test problem

From: Kevin Moore <talon.k_at_gmail.com>
Date: Tue Dec 27 2011 - 22:27:29 EST

Yeah both Vroms check good using the fluke, as does the ram tests on the
Pram, and Vram.

Kevin

On Tue, Dec 27, 2011 at 8:50 PM, teeray <teeray@earthlink.net> wrote:

>
> Does the Vrom test good using the Fluke? If not check Address and Data
> lines D4 -> H4
> and F2
>
> Tim
>
> -----Original Message-----
> From: Kevin Moore **
> Sent: Dec 28, 2011 2:24 AM
> To: vectorlist@vectorlist.org
> Subject: Re: VECTOR: Battlezone self test problem
>
> Thanks for the pointers William.
>
> I've been checking all those lines, nothing seems to work in Test mode,
> but everything seems to be toggling just fine in play..
>
> This circuit is so frustrating.
>
> Trying to track down where the breakdown is ugh.
>
> Kevin
>
>
> **
> On Fri, Dec 23, 2011 at 10:19 PM, William Boucher <wboucher6@cogeco.ca>wrote:
>
>> **
>> I agree with likely bad VSM, and probably right at the front end of it
>> since it draws nothing or practically nothing. Maybe none of the AVG
>> control signals are working.
>>
>> Best guesses are the major VSM / AVG signal decoders
>>
>> - bad latch (74LS175) atL K8, J8
>> - custom BPROM K7 plus J7 (74LS42 4-line to 10-line decoder) generates
>> /strobe0,1,2,3 and /latch0,1,2,3
>> - J10 - (74LS74 dual D-FF) pin 6 = signal /NORM
>> -check activity of signals OP0, OP1, OP2 entering BPROM K7 pins 1, 2, 3
>> respectively.
>> -check activity of signals /Strobe# and /Latch# signals coming out J7
>> pins 1,2,3,4,5,6,7,9
>>
>> Other possible bad ICs mishandling drawing data, generating bad DVY data
>> (so bad AVG PC values):
>> -bad shift register (74LS194) at
>> D5, D6, C5, A5, A6, B5
>> -bad gate at:
>> C6 (74S00), B6 (74LS14)
>>
>> Sometimes a bad IC runs warmer than the others of its same type so feel
>> around or use a laser temp gun. Maybe you'll get lucky.
>>
>>
>> William Boucher
>> http://www.biltronix.com
>>
>> ----- Original Message -----
>> *From:* Kevin Moore <talon.k@gmail.com>
>> *To:* vectorlist@vectorlist.org
>> *Sent:* Friday, December 23, 2011 7:08 PM
>> *Subject:* VECTOR: Battlezone self test problem
>>
>> 've got a new one.
>>
>> Ran fluke long and short ram tests good.
>> Rom signature tests come back good.
>> Tested aux board with good main no problem
>>
>> Game coins up, plays, but graphics are all screwy.
>> Put in Test and get one long continuous tone before watchdog kicks in.
>>
>> Manual states a long low tone will be present when Vrom B/C3 is bad.
>>
>> Have swapped both Vroms, and even tried the highscore kit. Still can't
>> get test screen to come up.
>>
>> Based on the fact the game does play, I'm guessing it's in the VSM area
>> somewhere.
>>
>> Any pointers?
>>
>>
>>
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Received on Tue Dec 27 22:27:39 2011

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