Re: How do i check the clock circuit?

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?

On Mon, Sep 23, 2013 at 3:27 PM, Ed Henciak <ehenciak@gmail.com> wrote:

> Joel,
>
> First, you're going to want to master using that logic probe that's in
> the mail. They're simple to use. It should have a light that indicates a
> toggling signal in addition to a "high" and "low" indicator. Some logic
> probes will simply light "high" and "low" at the same time in the event of
> a toggling signal.
>
> You'll want to use this toggle indicator as a means of sensing activity
> on clock lines. Please be aware that this doesn't mean the clock is
> "perfect" (you'd need an oscilloscope to determine that). However,
> "toggle" should be fine for now. I've debugged/fixed many PCBs with just a
> multimeter and logic probe.
>
> Next, all clocks originate at the oscillators, so start there and work
> your way through the ICs to which this oscillator connects.
>
> Hopefully this minimal info at least gets you started :-). If you
> can't wait and want to see if your clocks are toggling now, you could use
> your multmeter. First, you'd want to measure Vcc at the chip/oscillator in
> question (should be near 5.0V). If you measure the clock line with your
> meter, you should get a reading about half that (around 2.5V).
>
> Ed
>
>
> On Mon, Sep 23, 2013 at 6:06 PM, Joel Griffin Dodd <griffindodd@gmail.com>wrote:
>
>> Hi Guys.
>>
>> I'm going to attempt to repair my Star Wars board set as it won't boot.
>>
>> Never done this before, but I do have some advice as to what to look for
>> coming from a repairer with a good rep. Everyone in the community with a
>> good reputation is slammed with board work and not accepting new jobs, so I
>> thought this would be a good opportunity for me to start learning the art
>> of board repair.
>>
>> Unfortunately I don't have any background in this or electronics so I'm
>> coming in very green.
>>
>> First thing I have to do after checking all the voltage test points is to
>> check the clocks on the board and make sure they are all where they should
>> be.
>>
>> I have no idea what this means or how to go about it, what to look for
>> etc. I do have a decent Multi-Meter and I have a logic probe coming in the
>> mail the next few days.
>>
>> So, where do I find these clocks you speak of, and what is the actual
>> process I need to perform to check them for problems?
>>
>> Many thanks
>>
>> Joel
>>
>
>

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Received on Mon Sep 23 18:34:00 2013