Re: How do i check the clock circuit?

From: Pat Danis <patdanis_at_verizon.net>
Date: Tue Sep 24 2013 - 10:52:03 EDT

Joel:

I salute your dedication in attempting to get your board set working.  You might have considered starting on something a little bit easier.  I have been doing this for at least 10 years and my skill set at fixing boards is what I consider "very basic".  That is, running the self test and replacing chips identified as bad.  After that, if you do find something that is wrong, chances are you will not have the parts you need to fix it.  There are the very common chips scattered throughout he board that are easy to find, it is the unique parts that might give you the fits.

If you do find the problem, you need to be certain you know what you are doing when replacing chips.  Can you cleanly desolder chips without ripping pads or traces and reinstall a socket?  If not, You might stop now and consider sending the board off to a "pro" (Not me) and let them tackle it.  It costs more in the long run for them to fix other people's screw ups.  It is certainly admirable to learn to fix things yourself but it might be better to start on a simple board like a pacman etc.

There is a Star Wars trouble shooting guide available and a ton of information on the web about star wars issues.  Who knows, you might get lucky and find the problem and change a chip and be up and running.  (I doubt it)  Based on my experience with SW board sets, you have a long road ahead of you.  I know two guys who fix them and I consider them brainiacs when it comes to board repairs.  They still have problems sorting out all the issues.

Best of luck in your endeavors.

Pat

Thanks guys, the info on spotting a clock visually was especially helpful. Sometimes the skill level of guys that have been doing this work for such a long time skips past many of the most basic yet useful pieces of information that a newbie simply doesn't yet know. Now at least I know what to look for on the PCB in the 'real' world as well as the schematic.

On Tue, Sep 24, 2013 at 2:08 AM, Andre Huijts <a.huijts@upcmail.nl> wrote:

The clock signals are generated using crystals. They are easy to ID, usually a flat aluminum colored can:

 


More modem versions look like this, if you see these, the crystal has probably been replaced in more recent years:




This may sound weird but your first work should be visual. Check if the crystals are there at all and if they are still firmly soldered. I actually started measuring for a clock signal only to discover  some seconds later that it was missing :) The crystals often get damaged or broken off during stacking PCBs or transport because they stick out high above all the other parts. This is also why I prefer to replace them with the smaller modern types.

A general visual inspection is always a good idea. Look for damaged tracks, bad sockets etc. in case of SW PCB set, make very sure the interconnection board is on really tight.

Verstuurd vanaf mijn iPad

> Op 24 sep. 2013 om 10:49 heeft Andrew Welburn <andy@andysarcade.net> het volgende geschreven:
>
> You need to get the manual and schematics and read them, they you will know where all these things are...
>
> Andrew Welburn
> http://www.andys-arcade.com
>
>> On 23/09/2013 23:33, Joel Griffin Dodd wrote:
>> Thanks Ed!
>>
>> No problem on waiting for the probe to arrive, I'm moving house this
>> week so I have plenty to keep me busy.
>>
>> How do I physically identify a clock/chip/oscillator on a board? Also
>> how do I know which line out is the clock line?
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--------------------------------------------------------------------------- ** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org ** Please direct other questions, comments, or problems to chris@westnet.com Received on Tue Sep 24 10:52:34 2013