WTB: WPC-95 A/V board

[Greg Shanes]

Need it for a NGG.

Let me know what you have and what you want for it.

IT MUST BE A WORKING BOARD.

Greg

[ch...@team-em.com]

On May 18, 10:35 pm, Dino Naber <v...@foxvalley.net> wrote:
> Illinois pinball has NOS for $325.00

Seems like this would be a good one for Ed or Jim Knight to repro...
--
Chris Hibler - CARGPB #31, TeamEM

[John Wart, jr]

Not really

The one component on these that goes bad and is difficult to find would just
do the same thing on a new board.

<ch...@Team-EM.com> wrote in message
news:1179546514....@n59g2000hsh.googlegroups.com...

[GPE]

"John Wart, jr" <johnw...@johnwartjr.com> wrote in message
news:XL-dnbymV7515dPb...@comcast.com...

> Not really
>
> The one component on these that goes bad and is difficult to find would
> just do the same thing on a new board.

Ah, but when I redo boards - I don't believe in using items that are
obsolete or hard to use.
I'd remake it to emulate the ASIC ... and replace DSP with something more
modern.

At this point - my plate is too full, though. It takes me umpteen days to
find time to just route a board properly.

-- Ed

[Frank-Rainer Grahl]

I have seen more DSP failures, broken traces and cold solder joints on the DSP but
you milage may vary.

Regards
Frank-Rainer Grahl

-----------------------------------------------
www.pinballz.net - The #1 pinball forum for me

[Coin-Op Cauldron (Clive)]

Frank-Rainer Grahl wrote:
> I have seen more DSP failures, broken traces and cold solder joints on the DSP but
> you milage may vary.
>

Out of the 53 A/V boards repaired here over the last year, 27 were
repaired as a direct result of the A/V ASIC being faulty vs. 6 for
faulty ADSP-2105 DSPs.

Clive
---
Board repairs, EPROMs, servicing...

The Coin-Op Cauldron
103 Armistead Lane
Easley, SC 29642
(864)238-1707
http://www.coinopcauldron.com

[ch...@team-em.com]

Good data Clive. I'm glad that you are tracking failure root cause.
I'm sure it helps you to do that and hopefully it will help someone
intending to repro the board.
I'm glad this came up. I didn't know that the board was becoming rare.

[metallik]

> Out of the 53 A/V boards repaired here over the last year, 27 were
> repaired as a direct result of the A/V ASIC being faulty vs. 6 for
> faulty ADSP-2105 DSPs.

Good data there.. Question: Based on observations, could you tell
what was the cause of the ASIC faults on any of the boards? Did any
boards show signs of the high voltage being shorted into the logic
circuitry, or did they all appear to just die of natural causes?

(I realize it's possible to short out or ruin the ASIC with no visible
evidence, just curious if you ran into any obviously-blown ones).

The idea is to judge just how fragile that ASIC chip really is.

[martin]

I took a look at that board again.

The ASIC is overly busy - there's a lot of stuff run through that
part for what look like fairly minor DSP functions. A lot of the
complexity is driven by a design that was failry leading edge 15 years
ago. Reproducing it doesn't make sense. It needs to be redesigned with
a new architecture, which means figuring out the Williams command set
and data structures so that it can use the old ROM files.

[Coin-Op Cauldron (Clive)]

metallik wrote:
>>Out of the 53 A/V boards repaired here over the last year, 27 were
>>repaired as a direct result of the A/V ASIC being faulty vs. 6 for
>>faulty ADSP-2105 DSPs.
>
>
> Good data there.. Question: Based on observations, could you tell
> what was the cause of the ASIC faults on any of the boards? Did any
> boards show signs of the high voltage being shorted into the logic
> circuitry, or did they all appear to just die of natural causes?
>

No obvious cause for the faults other than the ASIC breaking down
internally. I thought that perhaps the failures were the result of a bad
production batch but the ICs have production dates for at least three
different years that I recall so that ruled that theory out.

I don't recall ever seeing an A/V board that had the logic blown as a
direct result of a HV failure as that would require the display HV to
short to the +5 volt rail and the HV/LV supplies are pretty well
isolated in the -95 system. A short of this nature is also very likely
to take the whole system out.

A/V faults range from failing to select the DSP RAM (which was
previously handled by external logic to the DSP on the DCS sound board),
to complete failure, to no video output, to no DSP communication etc.
The problems are varied.

> (I realize it's possible to short out or ruin the ASIC with no visible
> evidence, just curious if you ran into any obviously-blown ones).
>
> The idea is to judge just how fragile that ASIC chip really is.
>

There were no physical signs of failure that I recall.

[Frank-Rainer Grahl]

Guess I am lucky. Only 15 to 20 in the last two years. Most only had bad 160yF
caps. One a bad 79L05. Two worked after reflowing the DSP. One after replacing it.
One of the address lines was dead. I have two others here which were used for
parts. I can keep one if I can repair the other. The first still gives a ram error
but the ASIC has been replaced before. Doesn't look good. I already found some
problems but still no go. On the second the DSP was completely dead but I have only
removed it yet.