Re: Messed up my Black Widow

You could have an integrated circuit that has failed, causing the short.
I've had failures with the TL082's (for example) that took the whole board
down due to an internal short. These are very tricky to find. I don't know
how to effectively troubleshoot that without removing parts one at a time
(or at least lifting the Vcc leg).

As others haves mentioned, you could have caps that shorted too. Really
almost any part may have failed and you will need to check them
methodically.

Joel

Sent from my iPhone

On Jul 1, 2012, at 7:00 PM, John Huie <jehuie@sbcglobal.net> wrote:

I mean both.....when power is on I get no LED and when I removed the pcb
from the game, I measure zero volts between the ground and +5 test points.
Which makes sense since they are shorted now.

I've gone over the board pretty well with a magnifier but I'll do it
again. And I'll have my son with aspergers syndrome take a look as well
since he's amazing at finding issues like that. :)

And to be clear, when I'm measuring the resistance and getting a short this
is with the board removed from the game and all roms removed. Also, I
neglected to mention that I had also ended up swapping all of the socketed
chips over at one point so I've checked each of them for bent pins, lifted
traces, etc. Can't see anything that looks amiss. And I'm still getting
the short between +5 and ground test points with ALL those chips removed.

I also plugged the board into the game again with all chips removed and
still no LED or +5 reading there.

I'm thinking maybe I have a hosed socket. Which would be hellish for me to
find. I don't have a scope but I do have a logic probe. But getting no
power means that would be worthless I think.

And just an observation....I can't believe how responsive you guys are
compared to some of the enthusiast forums. I posted on KLOV and got very
little response to my question. I actually had a bit more on AHA but
there's very few tech type folks on there. So thank you even if I don't
get it going!

John

--- On *Sun, 7/1/12, vectorlist-steve <vectorlist@arcadehacking.com>* wrote:

From: vectorlist-steve <vectorlist@arcadehacking.com>
Subject: Re: VECTOR: Messed up my Black Widow
To: vectorlist@vectorlist.org
Date: Sunday, July 1, 2012, 3:27 PM

 When you say no +5 are you saying there is no +5 voltage measured at the
board test points or that the power led is not lit?

#1 I would recommend taking a few minutes and giving the board a good
visual inspection.
- Is there a cap or potentiometer that has been mashed down and shorting on
another component?
- Is the crystal and leads intact?
- Do you see any cracked components or other damage?

#2 Measure resistance across the +5 and GND test points next to the power
LED with the board disconnected
- I measured 1.575 K Ohms and 1.578 K Ohms on a second board so they seem
to be fairly consistent

#3 If you have an eprom programmer verify both sets of roms/eproms

#4 If you have an oscilloscope, logic probe or frequency counter you can
place on pin #40 of the 6502 CPU to watch for an active low reset

On 7/1/2012 3:08 PM, John Huie wrote:

  Well the boards are both out of the game right now but when they were in
I checked all fuses and made sure the interlock was on. I could swap out
the other board and get life.

--- On *Sun, 7/1/12, vectorlist-steve
<vectorlist@arcadehacking.com></mc/compose?to=vectorlist@arcadehacking.com>
* wrote:

From: vectorlist-steve
<vectorlist@arcadehacking.com></mc/compose?to=vectorlist@arcadehacking.com>
Subject: Re: VECTOR: Messed up my Black Widow
To: vectorlist@vectorlist.org </mc/compose?to=vectorlist@vectorlist.org>
Date: Sunday, July 1, 2012, 2:55 PM

 Interlock safety switches on the back door and front coin door in the
service mode position? ( Pulled all the way out )

If not that, how about a blow fuse? Nine out of ten times it's the simple
things that folks stumble on.

On 7/1/2012 2:50 PM, John Huie wrote:

  Thanks for all the tips guys. I think I tried everything you have
suggested so far. Here's the breakdown:

1) Inspected all chips. There are no bent or broken legs. All came out nice
and straight.

2) No obviously damaged sockets. I examined every pin of every socket
visually with a magnifier top and bottom. They all appear clean and have
clean solder on the bottom.

3) Can't see any damage to traces under the chips that could be leading to
a short. Examined each with a magnifier also.

4) All roms were put in the correct way around.

5) When I checked the resistance between Ground and +5, I was just using
the "Diode" setting on my meter. With chips in or out. On the board in
question I'm getting an immediate beep and the reading is 0.000. On the
other board I get no beep and it reads 0.291 resistance. Whatever that
means.

6) Neither board is plugged into the harness when I'm checking this.

7) Thanks for the chart Jordan. Now I see where I screwed up. Step one!

Any other ideas? Oh and David, if you can hit me up privately and let me
know what you charge to repair these that would be great. I've got two
that could use repair.

John

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Received on Sun Jul 1 19:11:48 2012