Film-Tech Forum ARCHIVE: DTS-6D peculiar wake-up behaviour

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Posted by Rob J. Buskop (Member # 3338) on 05-25-2019, 05:30 AM:

I'm puzzled with the "switch-on" reaction of my 6D unit.When I switch it on (front switch)first time of the day most of the time nothing happens. All the leds remain dark. When I leave it like that for some time nothing changes. When I switch it off and switch it on again, then I get the system led and the cd rom led lit,like it should be.
Occasionally I only get the system led when first switching on ( that also keeps everything out of order...), but mostly it's all off and only after the second try things wake up. When I repeat the test some hours later, the phenomena does'nt occur. Next day, same story though...What could be the cause of this? Any thoughts about this behaviour are greatly appreciated! Thanks,
Rob.

Posted by Scott Norwood (Member # 30) on 05-25-2019, 05:57 AM:

Bad power supply?

Posted by Rob J. Buskop (Member # 3338) on 05-25-2019, 10:03 AM:

Hi Scott, Well that's what one thinks of first of course. What the specific explication is of the SPS behaving like that is another matter. Suppose the best thing to do is a simple switch over and to see what happens.If all's fine then, we'll not delve into the PS's inner troubles. Thank you for your comment.
Very best,
Rob.

Posted by Paul Finn (Member # 10726) on 05-25-2019, 11:31 AM:

FWIW: I have seen a DTS-6D that powers up correctly after being off for some time (sometimes days) but, if it is powered off after it has booted and/or been used, and then turned back on again after a few seconds, it comes up dead until it is switched off again and sits for 10-15 minutes. This seems to be the opposite of your unit, but it's operation is entirely normal when it is powered on. No cause for the unexplained operation has been determined, but as Scott suggests it may be power supply related.

Paul Finn

Posted by Rob J. Buskop (Member # 3338) on 05-28-2019, 08:58 AM:

Thanks Paul for your appreciated comment. It remains an odd behaviour and my spare unit does'nt perform these unusual tricks. Might be some flaw in the switching power supply or alternatively something odd with the mom board. I'll have to dismount the unit and do a careful analysis of the supply voltages. But since it all works after some switch gymnastics it tends to reside on the back burner a bit.... Will proceed as I should and will report back if something interesting is found.

Posted by Scott Norwood (Member # 30) on 05-28-2019, 11:25 AM:

Have you measured the output of the existing power supply? That might be a starting point.

Or just get another AT power supply and try that. They can't possibly be that expensive. I know that others here have posted recommended models that are known to work in the 6D here in the past. I could loan you one, but I'm not sure if they are multi-voltage; I doubt that the trans-Atlantic shipping would be cheaper than just buying a new one, though.

Posted by Mark Gulbrandsen (Member # 72) on 05-28-2019, 03:35 PM:

I agree! It's most likely a bad power supply. Many of the things are 25+ years old now! Almost every single one I had to repair had a bad power supply, I usually repaired them right in the theater. Not always quite the same with XD-10 though. Depends on which motherboard you have...

Mark

Posted by Rob J. Buskop (Member # 3338) on 06-13-2019, 11:19 AM:

O.K. Here's the conclusion of the story: Managed to get a new (!)) 300W ATX 20 pin pwr. supply (these have + and - 5V) for less than $20.00. Installed this post 2002 manufactured unit with an AT/ATX 20 pin adapter to hook it on the motherboard. The adapter also incorporates the on/off switch connection wires. After this was done everything was behaving perfectly again.
Checked the old supply: +5V O.K. -5V 4.0 +12 was 10.3 and -12 10.5....... Standard failure: some electrolytic caps had "bowler hats". Could easily be repaired but the replacement was the better option in this case. Thank you all for your input!