Re: Asteroids/Asteroids Deluxe

Hi Andy,

I fixed one of these a while ago without cutting all the chips off. My
board had a reading of about 6.5 ohms if I remember correctly. I checked
the continuity in a variety of places and noticed there was a slighty lower
value in one row of chips. Something like 6.4 ohms in a middle row. It
took several chips, but one of the chips in that middle row was the bad
chip. You could try that and see if there's a difference on your board.

I think there's a technique with using a large amperage 5v power supply to
destroy the short (look for melting/flaming/exploding chips) but I've never
tried that one myself. (Clay told me about this one I think).

There's also some sort of instrument you can buy that tests for
shorts. Here's an example...

http://www.metermantesttools.com/products/SF10/SF10.asp

I've never used one myself so don't know how well they work.

-Werner

At 12:10 PM 8/23/2001 -0300, you wrote:
>ok, so here is my very troublesome problem.
>
>I have 2 Asteroids boards and 1 Asteroids Deluxe board and I meter across
>the BIG FAT GND trace and the 5v FAT line (these fat strips are actually
>striped down the board in alternating patterns GND, 5V, GND 5V...etc) to
>check and I find that board #1 is 3 Ohms, Board#2 is 19 Ohms an board#2 is
>90 Ohms. These are essentially shorts. My multimeter (put in continuity
>mode) beeps (continuous tone) to let me know that it is in fact a short.
>
>So.... Given the fact that these are shorts (and all my known working boards
>are not shorted - obviously since that would be close to tying power to
>Ground), I am at a loss. How the heck does one determine what component is
>doing this (outside of an actual solder blob or trace issue). Anything, and
>I mean, pretty much anything can cause this. Capacitors (my first pick),
>faulty chips (these potentially could fail in such a manner as to short
>their GND and VCC lines, can't they), transistors etc...). Making
>measurements on the board is now useless since every component that ties to
>both GND and VCC will register a short. For the life of my, I don't know
>how to figure out which component is responsible without yanking every damn
>chip or every damn cap that goes across 5V and GND.
>
>Any help, and I mean any help, would be appreciated.
>
>Cheers
>Andy
>
>
>
>Andrew Evrovski
>HPC Development Director
>Cyberplex
>t: 902.429.4721 ext.109
>f: 902.423.0899
>www.cyberplex.com
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Received on Thu Aug 23 09:45:08 2001