Re: Messed up my Black Widow

Maybe you can use this trick:
Wet your DVM to diode test, hook up the plus (red) lead to the GND (yes) with a clamp. the using the minus (black) lead start touching all pins on all chips (sounds like you can rule out the ROMs though). When you have a feel short (beep/ 0 on display) and the pin of the chip is not connected to ground, you may have found the bad chip.

Read that from.....argh whats the guys name....a very experienced arcade tech that wrote a nice book and gave a lot arcade tech classes...

It doesn't always work but I did find one bad chip one using this method. Since you seem to have a dead short on the 5V this may work.

...and I'm Level42 on the forums. Problem is that KLOV has so many new postings each day...

Verstuurd vanaf mijn iPad

Op 2 jul. 2012 om 01:11 heeft Joel Rosenzweig <joel@helitronix.com> het volgende geschreven:

> 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> wrote:
>>>
>>> From: vectorlist-steve <vectorlist@arcadehacking.com>
>>> Subject: Re: VECTOR: Messed up my Black Widow
>>> 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 Mon Jul 2 02:27:07 2012