Kinoton Sound Power Supply

[Steve McAndrew]

Hi

I am after some info on a Power Supply Board for the Kinoton Dolby Digital reader that I am trying to fault find for a friend.

On other identical boards I have used, the end two terminals on the long connector need to be connected to enable the LEDs. The board I am working on seems to enable the LEDs without this connection, any reason why this should be?

Does anyone know what the jumper on the board does?

Thanks

[Sean McKinnon]

If you are talking about what I think you are that is to enable the LED to be switched by either the changeover or the motor on relays depending on your setup.

[Steve McAndrew]

If you are talking about what I think you are that is to enable the LED to be switched by either the changeover or the motor on relays depending on your setup.

Yes, on other cards as far as I can remember you have to connect the last two terminals to make the LEDs work. On the card I am trying to fault find they come on without these terminals connected. I am wondering if the jumper on the card enables the LED without this connection

[Tony Bandiera Jr]

Yes, on other cards as far as I can remember you have to connect the last two terminals to make the LEDs work. On the card I am trying to fault find they come on without these terminals connected. I am wondering if the jumper on the card enables the LED without this connection

Since no one else suggested it yet.....

Try removing the jumper. If the leds stay off then you've answered the question.

First rule of troubleshooting anything: Check (or try) the obvious first. Don't overthink the causes of a problem before eliminating the obvious.

As an example, a long time ago, in a cinema far, far away...

I had CP200 that would randomly jump into preset 4 (in this case, format 60 Non sync) at random. This call took me over two hours to resolve because I lost sight of the first rule of troubleshooting. I .told this full story on the old forums but will Cliff Note it here.

After checking the automation interface, pulling and reseating all of the cards in the processor, disconnecting the automation interface, banging on the rack, wasting time calling other techs for suggestions, and so on...the solution came about when my friend who was with me on call accidentally let the door next to the rack slam. The processor did a hard power down and came right back up. At that time it finally dawned on me to check the incoming AC power cord at both ends. The IEC end at the PSU was fine. Following the cord to the other end....

Buried in the back rear corner, some genius had decided that cutting the plug ends off of the equipment and landing them (somewhat neatly) on a set of screw terminals was a great Idea. The problem ended up being a loose screw on the neutral side of the CP200's psu cord. Five seconds with a screwdriver and the problem was fixed.

As to WHY the loose connection caused this: The CP200 was set up to power up in the Preset 4 mode automatically. The loose connection would fool the processor's logic into thinking that it was being powered up, but the interruption was not long enough to cause any audio glitches. (Anyone who has ever accidentally powered down a CP 200 without killing the amps knows the interesting and extremely LOUD noises it makes. )

Luckily for me, the theatre manager was very nice and I had saved her bacon many times before, so at least in her eyes I didn't look to her like the fool I felt at the time.