Film-Tech Forum ARCHIVE: Dolby CP750 Back Up Question

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Posted by Michael Harlow (Member # 1353) on 01-31-2016, 12:06 PM:

Hello, hope you can help?
I have a CP750 which is beginning to fail (fails to boot up, etc)
Is there a way I can save all of the CP750 settings so that if i replace it i can just reload the configuration of the old one on to the new one?
I can log in via the CP750 set up software, but i cannot see an obvious "save settings" or back up settings..
Any ideas lovely people?
Thank you as always for your help

Posted by Brad Miller (Member # 2) on 01-31-2016, 12:25 PM:

This will make you angry, so apologies upfront.

Once you are connected and you can flip through the tabs to see the settings and such, click FILE>SAVE.

To re-upload, connect and then click FILE>OPEN.

Yup, it's that simple.

Posted by Pete Naples (Member # 761) on 01-31-2016, 01:21 PM:

Michael, the PSU is a notorious fail point.

The good news is they are available and are an easy swap.

There is also an external back up version.

Posted by Gavin Lewarne (Member # 5397) on 02-01-2016, 08:33 AM:

As pete said, its an easy swap to replace the internal PSU.

I ordered one from Omnex last week, and replaced the (still good) one in my CP750, keeping the old one as a spare.

The one I pulled out had some pretty low quality caps on it, a brand I have not heard of before. The replacement came with NichonChemicon caps, a top quality brand.

Since replacing it I have not had the weird "display dim when power on until you change the display contrast setting" bug happen.

Took me about 5 mins to swap it out

Posted by Steve Kraus (Member # 476) on 02-01-2016, 10:45 AM:

Does anyone make their own low cost backup supplies by fitting a 4-pin XLR to an inexpensive generic PS? I see it needs plus 15, minus 15 and plus 5 volts.

Posted by Carsten Kurz (Member # 5396) on 02-01-2016, 11:33 AM:

Someone told me the original internal OEM power supply fitting the CP750 can be bought on Amazon for as little as 30-40US$. So, why bother to attach something generic?

I can see one reason, though: If the internal supply fails, it is quicker to have an external supply connected for the rest of the day than to pull the CP750 out and fit the new internal one.

Maybe the internal supply can be transformed into an external supply with just a few wires and connectors?

- Carsten

Posted by Steve Guttag (Member # 268) on 02-01-2016, 12:39 PM:

I'm curious what the OEM part number is on the main power supply for the CP750.

The Back Up supply is quasi over the counter but one does have to put their own NC4FX connector on it and it is VERY tight in there considering all of the commons have to land on one pin. The stock supply is with a DIN connector.

Posted by Steve Kraus (Member # 476) on 02-01-2016, 02:47 PM:

Maybe they can be commoned in the supply (depending on gauge) or do something just outside the XLR, to be hidden with heat shrink.

Posted by Steve Guttag (Member # 268) on 02-01-2016, 04:19 PM:

You can do it inside the XLR connector (we do and Dolby's OEM does)...just saying...that is the frustrating part.

Posted by Harold Hallikainen (Member # 5405) on 02-01-2016, 08:50 PM:

Do these power supplies really fail frequently? We rarely see a failed power supply.

Harold

Posted by Pete Naples (Member # 761) on 02-02-2016, 05:10 AM:

Harold,

I've had 100% failure rate on a three screen site, within six months of install.

There was, according to Dolby, a batch of PSUs which had some poor components. But I would add that I've seen failures in early CP750 and current CP750. Sometimes years after install, sometime minutes.

The same PSU is used in the DMA8+, I've seen multiple failures on those too.

Posted by Carsten Kurz (Member # 5396) on 02-02-2016, 05:27 AM:

There had been a few issues with AP20 PSUs as well, but I can not judge if that was within normal statistics.

There is a 'certain uncertainty' about product quality when you source a major component like a PSU externally, because the production/component quality is not under your own control. So you may end up with a bad batch.

- Carsten

Posted by Steve Guttag (Member # 268) on 02-02-2016, 06:48 AM:

Of the multiple hundred CP750s we've put in...we've had one PSU fail...it was shortly after it was installed (months, not minutes). We've had zero DMA8+ PSUs fail.

I'm inclined to believe the batch theory on failure.

Too many people have complained about it to not have something there.

Posted by Matthew Heuer (Member # 9199) on 02-02-2016, 07:15 AM:

We have 16 CP750s, of those we lost 3 due to power supply failure. 1 a couple days after install, and the other 2 after a year or so of service. All are on UPS and left on along with server 24/7 typically. In speaking with dolby they admitted that there were bad batchs of PSUs and most of our serial numbers fall within that batch. Doh!

Posted by Carsten Kurz (Member # 5396) on 02-02-2016, 07:31 AM:

quote: Steve Guttag
The Back Up supply is quasi over the counter but one does have to put their own NC4FX connector on it and it is VERY tight in there considering all of the commons have to land on one pin. The stock supply is with a DIN connector.

Couldn't you group the commons on the supply-side already?

- Carsten
- Carsten

Posted by Steve Guttag (Member # 268) on 02-02-2016, 11:15 AM:

The CP750 back up supply is an enclosed model with a molded cable.

It isn't the end of the world, it is just tight in there.

Posted by Carsten Kurz (Member # 5396) on 02-02-2016, 03:32 PM:

But in that case it comes with the connector prefitted anyway?

I was talking about converting an internal supply (or other suitable source) to an external supply by attaching the XLR to it.

- Carsten

Posted by Steve Guttag (Member # 268) on 02-02-2016, 05:24 PM:

No...off the shelf it is a DIN connector...the CP750 uses a 4 pin XLR so one has to do the connector swap.

Yes, if you were to source your own supply with suitable voltage/current/noise characteristics, you can indeed common up on the supply end.

Posted by Steve Kraus (Member # 476) on 02-03-2016, 11:09 AM:

Do we know the OEM part numbers for either the main supply or the backup? Or perhaps just the current requirements for each of the three voltages?

Posted by Carsten Kurz (Member # 5396) on 02-05-2016, 02:22 PM:

A fellow projectionist told me now it is:

http://ipdpowerstore.com/SRP-40A-3002_p_31.html

At least the voltages seem to be correct.

http://www.amazon.com/Integrated-Power-Designs-Srp-40A-3002-Srp40A3002/dp/B017ABYJSK

- Carsten