Film-Tech Forum ARCHIVE: CP 650 Panel Blinking

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Posted by Martin McCaffery (Member # 37) on 07-07-2016, 11:09 AM:

I just noticed something I hadn't seen before and would like to know if it is an indication of upcoming trouble.

When I boot up the CP 650, the front panel blinks on and off rapidly, with an audible clicking noise. So far, it then continues to boot up fine.

How worried should I be?

Posted by Ron Funderburg (Member # 4561) on 07-07-2016, 11:56 AM:

I haven't had a Dolby unit in a long time but it sounds like an error code. Your manual should have someplace where that is listed. If it was a computer I know it would be an error code but on a sound unit not sure.

Posted by Tony Bandiera Jr (Member # 2365) on 07-07-2016, 12:14 PM:

I once had similar symptoms crop up on a piece of (non-cinema) gear....I found the problem when one of the power supply electrolytic capacitors exploded. [Eek!]

You need to look at this on a deeper level before it craps out completely. AFAIK the CP650 does not have or ever had any kind of audible alarm or mini speaker inside as a PC motherboard does...

Watch the unit carefully during the boot up process...if all of the LEDs and display are flashing during this problem, the power supply may be going out. You can also pull the front panel off (one screw behind the drop door and pull the faceplate off) and look through the vents at the bottom left..IIRC there are power supply LED's on one of the mainboards, they should come on steady and stay on during bootup.

Oh, and check the obvious first..make sure the power cord is fully seated in both the processor end and at your AC outlet. A loose cord can cause problems like you describe.

Posted by Mark Gulbrandsen (Member # 72) on 07-07-2016, 12:20 PM:

Hey... it's a Dolby, so always suspect the power supply first. I can't tell you how many 650 power supplies I have either replaced or rebuilt on site in the last 7 years. And they can be rebuilt fairly easily....

Mark

Posted by Sam D. Chavez (Member # 1841) on 07-07-2016, 03:53 PM:

quote: Mark Gulbrandsen
either replaced or rebuilt on site in the last 7 years. And they can be rebuilt fairly easily....

I have quite a box of bad 650 power supply bricks from three different vendors, IPD, Lambda, and Power Solution. Which brand were you able to repair in the field? What parts were typically replaced? Me thinks you you exaggerate as you seem to sometimes do.

Posted by Mark Gulbrandsen (Member # 72) on 07-10-2016, 09:23 PM:

Sam,

I have posted a picture below. These were 650's in Westates Theaters all over Utah. We actually had two power supplies die in one weekend in Southern Utah once. They were all the same brand and all were affected by the capacitor plague (same problem as the DTS XD-10 motherboards). You'll see obvious stuff leaking out the tops of the caps and or the tops will be bulged up. I replaced all the caps that were of the same brand and I think there were six caps per board total. So if you have any that are obviously leaking, then replacing those caps should fix them. Cost is about 8 to ten bucks vs some ridiculous price Dolby was charging for them at the time.

Mark

Posted by Sam D. Chavez (Member # 1841) on 07-13-2016, 03:10 PM:

Can't tell from this pic which brand and of course the caps are the first suspect component. After that, it gets mighty tough to fix anything in the field.

Posted by Mark Gulbrandsen (Member # 72) on 07-13-2016, 05:03 PM:

If it isn't the caps then the whole thing gets replaced, not worth more then the hour it takes to pop new caps in. Trick is to catch it and rebuild before all the rails are lost. If you've lost one rail or even two but have one working you kn ow the switcher part is functioning. That's a sign of something else failed behind all those caps. Many of these power supplies are current limited by design and if a cap shorts it will likely just shut down. There are also places that repair these power supplies.

Dolby wan't the only company hit by the capacitor plague. Hundreds if not thousands of companies were. Its certainly not their fault and I haven't lost a 650 power supply in about 5 years now.

Its kind of like a miniature Wrong Switcher. Those were not very hard to fix for the most part, a bit time consuming though. Just replace the main caps and all the power switching transistors, check the commutation diodes ad replace if necessary replace the four high speed diodes and a couple of fuses. I am still doing repairs on those to this day. Wrong sold the spot light division to a company in TX and I am told getting anything done on them now is worse than having surgery.

Here is my original post on the CP-650 power supply issues.
http://www.film-tech.com/ubb/f1/t010460.html

Mark

Posted by Marco Giustini (Member # 4544) on 10-16-2016, 05:38 AM:

Hi,

I'm attempting to repair a 650's PSU for fun - it's my own 650 which is not being used for commercial purposes so no rush.

The PSU seems fine, all rails are dropping and becoming unstable after 5-10m of operations.

Capacitors seem fine looking at them. Does anybody have any hints on what to check first?