I am here working on Saturday doing service returns for our programming lab.

We usually get devices back from the customer with the explanation being "broke", "erroneous", "bad", or "erratic", with no other information.

I get one today that says "will not respond". So I open up the box containing the base (keeping in mind these controllers cost around $1500) and I see a large arc flash burn eminating from a capacitor. Hmmmm.

I open the box containing the controller and match the arc flash on the base to the arc flash and melted hole on the controller. Hmmmm.

I was going to write on the service return order that it wouldn't respond because they let the magic smoke out of it, but people do read those things.

Robert

Edit
I was also thinking about an information request to our service department head reading as follows.

Would not respond to:
A: Aggresive tickeling.
B: Animal sacrifice.
C: C.P.R.
D: Peak time cell phone calls.
E: Flattering comments.

(He has a good sense of humor.)

[This message has been edited by rad74ss (edited 06-11-2005).]

rad74ss:

Got pics?

I will try to remember to bring my camera on Monday.

From Rad74ss.



Roger

Robert:

Looks like someone applied a rather high voltage to those terminal blocks causing the cap to blow....are those for data or power supply input?

Reminds me of a recent incident where a not-too-bright gal at a company put 120volts onto the 12vdc bus of an AMX system, frying everything with a lot of magic smoke release! She even had the nerve to deny it when confronted with the cord someone(?) had made up, which she admitted she had plugged in! "No one told me it would do that!"

Total tally around $5,000 worth of equipment destroyed.

I was recently informed that the customer said there was a short somewhere in the cooling tower system that caused all of the damage.

I am not convinced though. The only things burned up on this unit were on the 24V side of a transformer. Nothing else on the unit had to be replaced. This unit mated to a second unit that ran off of the same mains.

The units were interconnected via communications cables and some wires for dry contacts.

I think somebody accidently hooked up 120V to the 24V side. I do not remember how many times I have been on service calls that started out like "I had to jumper some stuff to get the compressor to start". !!!!!!

This controller is for an industrial chilled water evaporator.

To play devil's advocate, capacitors do blow up on their own sometimes. I've seen a few that have gone off, and it looks pretty much like what you have there.

Maybe this is going to turn into a business thread....

Remember, you never win an argument with a customer; even when you're right, you lose! Consider for a moment the great success Sears' had with their 'no questions' guarantee on their hand tools.

The thing that makes me think that it was incorrect voltage is that everything on this particular transformer (except the transformer itself) was burned up. This included the controller, the transducers and their power supply, and the amp donuts. There is another controller on the matching unit with the same components and nothing happened to them.

Of course it is hard to troubleshoot the exact cause if you are not on site. We generally always send the customer a new controller ASAP so that they can get the system back on line. Then it is up to service to figure out who pays for it. These controllers have a lot of wiring and it ends up costing somebody a large quantity of money to have one completely replaced.