Film-Tech Forum ARCHIVE: DA20 startup problem

This is topic DA20 startup problem in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Raymond Massard (Member # 2300) on 06-30-2006, 11:13 AM:

I just installed a second-hand DA20 connected to a CAT700 reader. On starting up the DA-20 the first time it sigalled HELP0 thru the 7-segment display. Since we were in a hurry to resume shows in the theatre we focused on putting analog and DTS on which was no big problem.
After that we notices that the DA20 had resumed normal operation except that the error rate was too high. I changed the lamp in the CAT700 and the DA20 started decoding correctly (error rate 4, still high but acceptable). So all that needed to be done was to set the digital delay and the surround delay to the correct values, what we did. But after that the DA20 would refuse to startup. The display would show the correct startup sequence c-r-L, start decoding for a second or two and then starting the whole sequence again, endlessly.
We tried all the usual stuff like resetting, taking out and resettling all the boards, to no avail.
Finally I found out that setting the test dial switch beneath the 7-segemnt display to 1 (instead of 0) the DA20 would startup and continue decoding after setting the dial back to 0. But after a new restart the sequence above would resume cycling endlessly. Leaving the dial at 1 the processor appears to work fine.
Anybody around who has an idea what's happening here ?

Posted by Ken Jacquart (Member # 369) on 06-30-2006, 07:45 PM:

First suggestion: Measure the +5volt rail with a digital volt meter. Test point located on the Cat 670 card near the bottom. Maybe, just maybe you have an older unit that exhibited the problem of burning molex connector in the power supply.

If the voltage turns out okay, then maybe you have a problem with the Cat 673 card itself. Of course, re-seat all the cards is standard practice in any older unit.

Posted by Raymond Massard (Member # 2300) on 07-01-2006, 10:12 AM:

Checked the voltages. All ok and slightly above nominal values. Does anybody know what's different when using test dial on position 1 rather than 0 ?

Posted by Raymond Massard (Member # 2300) on 07-09-2006, 04:19 PM:

Checked some further on this issue: in fact on the left cat671 the upper red light was constantly on whereas the same led on the right cat671 was sometimes flashing shortly. I swapped the cards and now BOTH cat 671 have their upper red light constantly on. After reswapping the cards both leds are still on. Nevertheless if the test rotary swith on the cat673 ist on position 1, the DA20 works absolutely fine. I cannot imagine both cat 671 cards dying within 10 days. Does anybody have a hint.

Posted by Mark Gulbrandsen (Member # 72) on 07-09-2006, 05:40 PM:

I recently had both 671's go bad in a CP-500 in TWin Falls. I would say that both failing together is very rare.

Mark

Posted by Larry Zuverink (Member # 1483) on 07-10-2006, 02:26 PM:

I've had that Molex connector be bad even though the voltage was reading good. I've always soldered the connections from the power supply directly to the posts inside of the unit on those older DA20's. It has fixed this same problem about 5 times. If you have another DA20 you might want to try another power supply or even clean those connection really good before trying this though. If cleaning the contacts works, The problem will return.

Posted by Mark Gulbrandsen (Member # 72) on 07-10-2006, 07:16 PM:

Larry,

I agree 100% solder them directly to the board and then its never a question. I also have had many Molex's fail in CAT 700's lamp supply, same thing done there and never a problem again.

Mark

Posted by Raymond Massard (Member # 2300) on 07-15-2006, 05:12 PM:

Ok, so I soldered the wires directly to the pins. It didn't solve the problem except that one of the CAT671 behaves normally again (red leds out). But the other one still shows the error and makes the DA20 reboot endlessly.
Does the cable that connects the power supply to the backplane also have a molex on the backplane side ?
Does the DA20 draw more current on a specific voltage at startup or load ?
BTW: Checked the molex on the cat700 and it looked REALLY bad, soldered the wires directly to the pins as well.

Posted by Raymond Massard (Member # 2300) on 07-17-2006, 01:12 PM:

Finally soldered the power supply cables on the DA20 backplane as well. Result: All 4 red leds on the cat 671s are lit now.

Posted by Ken Jacquart (Member # 369) on 07-24-2006, 02:50 PM:

Raymond,

A few things...

Placing the CAT 673 rotary switch to position 1 forces the "link ignore" mode. It forces the system to ignore the fault indicators. Since you are seeing multiple red LED fault indicators on your CAT 671 cards, you may or may not have a bad card or two. I have seen instances where a fault indicator is on, and after re-seating the cards, all went away. I'm sure that you've re-seated these cards by now.

I also suggest that you take a look at field bulletin 219 and verify that this is not your problem (this should've been weeded out many years ago though).

If you have the opportunity to get your hands on another CAT 671 card, try temporarily swapping them one at a time to discover which card might be bad.

-ken

Posted by Steve Guttag (Member # 268) on 07-24-2006, 06:35 PM:

I just had a pair of Cat 671s die in a CP500 following the CP500's power supply going kaput. Oddly enough, three out of four sections (between the two cards) were dead...one was still trying to slug on through!

Sadly, the CCD camera also bought it on the power supply failure.

Steve

Posted by Ken Jacquart (Member # 369) on 07-25-2006, 12:29 AM:

Steve, I believe that your particular CP500 failure qualifies you for our t-shirt cotton currency giveaway at a bare minimum...

Posted by Raymond Massard (Member # 2300) on 07-25-2006, 09:18 AM:

Thanks Ken,

No, the cards are not in the lot discribed in the field bulletin about bad RAM chips. I should have a couple of cards to test with tomorrow.
I am afraid the cards have been destroyed by excessive voltage. When I started checking the voltage rails I noticed that the 5V rail showed 5,22 V which is more than actually acceptable. I have since reduced the voltages by means of the adjustable resistor on the power supply but the damage might be done.