did I toast my 2800A SCR?

[Matt Carpenter]

Here's an easy question for the right person. I'm hacking around with an
old computer and I wanted to find a ground to use as a reference point.

I just briefly touched a +5V signal (I think it was the clock) to the anode
of an SCR on the power supply. Bingo, computer. Later, I confirmed the
computer still worked with a spare power supply I had handy, so I toasted
the power supply.

Now, the power supply only has a bunch of passives & diodes, an SCR (2800A)
and two regulators (SGS L296H-5 and L296H-12). So, I think it was the SCR
that was fried, but I'm not sure how to confirm it.

Any opinions; does anyone support/reject my guess?

Of course, I could just replace the SCR and see if the power supply works,
but it's a little bit of a hassle to get a replacement.

Radio Shack doesn't carry SCR's anymore. However. they do have a triac that
I may try in its place. It's a DC switching power supply, so, I think it
would work?

-Matt

 

[Sofie]

Matt Carpenter:
Why don't you take the SCR out of the circuit and test it???
http://www.repairfaq.org/sam/semitest.htm#sttth
For more information about troubleshooting and testing you should go to the
website for this newsgroup at
http://www.repairfaq.org/
With a little searching you will find a wealth of information there relevant
to your questions.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
---------------------------------


"Matt Carpenter" <mkath@whitehouse.gov> wrote in message
news:vvhk6jjf83ctdd@corp.supernews.com...

Here's an easy question for the right person. I'm hacking around with an
old computer and I wanted to find a ground to use as a reference point.

I just briefly touched a +5V signal (I think it was the clock) to the
anode
of an SCR on the power supply. Bingo, computer. Later, I confirmed the
computer still worked with a spare power supply I had handy, so I toasted
the power supply.

Now, the power supply only has a bunch of passives & diodes, an SCR
(2800A)
and two regulators (SGS L296H-5 and L296H-12). So, I think it was the SCR
that was fried, but I'm not sure how to confirm it.

Any opinions; does anyone support/reject my guess?

Of course, I could just replace the SCR and see if the power supply works,
but it's a little bit of a hassle to get a replacement.

Radio Shack doesn't carry SCR's anymore. However. they do have a triac
that
I may try in its place. It's a DC switching power supply, so, I think it
would work?

-Matt