Film-Tech Forum ARCHIVE: Dolby DSP-100 (Fan 3 Error)

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Posted by Kerry Fleming (Member # 1657) on 01-31-2018, 05:32 PM:

I know that this equipment has three fans built into it.
Two in the back. Which are field serviceable.
And one in the front which is not.
There is a hidden diagnostics LED panel under the front cover.
One of the LEDs is marked Inner. Another Outer.
In this case the Inner LED is illuminated RED.
The System Log is indicating a Fan3 Error.
This is a Cautionary Alert!!
Has anyone run into this Alert before?
Can anyone advise me what the respective fan numbers are?
Dolby no longer supports this equipment as of 2014.
Legacy support was given to Venture Manufacturing.
They have no parts or service available any longer.
Finding parts for the DSP-100 is proving to be challenging!

Posted by Stephan Shelley (Member # 8587) on 01-31-2018, 06:25 PM:

You can carefully open it up. Just make sure not to disturb the video decoder card. Do not remove it. You should be able to source the fans on the internet.

Posted by Steve Guttag (Member # 268) on 01-31-2018, 06:32 PM:

I believe the "Inner" is the one facing in and the outer is the one facing out (They are merely two fans stacked upon one another.

The spec I have on the fan is:

Comair-Rotron CR0812MB-A70GL(T) 12VDC 80mm x 80mm x 25mm.

It is a simple 2-wire fan, nothing proprietary. You will need to clip the old fan wires off the old connector and solder the new one onto it (have heatshrink available too). It isn't such a bad job. Just note, the DSP100 cabinet typically has security screws (torx security (with the high-point peg)).

I've found that the DSS100 is MUCH more likely to loose a fan (they tend to gum up and just stop turning or slow down). For those, it is a pain due to where you need to get to the nuts. Using some large/long "bent" needle nose pliers can be a life saver.

BTW...there is a document on changing the DSP100 fans. A call to Dolby Tech Support might score you with it though mostly common sense is sufficient. Remember, there are things in there that don't react well to people poking and prodding.

Posted by Carsten Kurz (Member # 5396) on 02-01-2018, 05:59 PM:

If it's two wire, does the dsp100 actually notice it is failing? Is there another sensor for actual flow?

Posted by Steve Guttag (Member # 268) on 02-01-2018, 09:48 PM:

Strictly current in/out of range, I guess. But it is definitely just 2-wire. Note, the CRU rack mount frames that have those FAN LEDs...same thing.

Posted by Kerry Fleming (Member # 1657) on 02-04-2018, 10:20 AM:

Thank You for your replies!
Steve; I deciphered it as you did. Inner fan/Outer fan. Both on rear panel of DSP100. I had the fan replacement instructions from Dolby. And I have replaced the Inner Fan corresponding to the Inner LED illuminated. But, no joy! The Red LED remains. As does the Cautionary Fan 3 Error warning. Awaiting the arrival of another replacement fan. Figure I will go get the other one in back.

Posted by Steve Guttag (Member # 268) on 02-04-2018, 11:03 AM:

Since the plugs are right next to each other, did you try swapping the plugs to see if the problem moved? Maybe they were plugged in wrong.

Posted by Greg Routenburg (Member # 1742) on 02-06-2018, 09:47 PM:

The DSP100 actually has 4 fans, two at the front and two at the back. When one fan fails, I replace all 4. The two at the back are very easy to change and Dolby has a Field Bulletin to walk you through it. The front fans were not deemed to be field serviceable by Dolby but it can be done if you're very careful. As mentioned previously, don't disturb the circuit boards in the unit during the procedure. If you're looking at the unit from the top down, they are in the front left corner of the unit, directly in front of the two power supplies. In order to remove them, you need to remove both power supplies, the right wall of the power supply bay and the power supply back plane. There are a couple of screws holding the sheet metal together near the front that I usually turn out with needle nosed pliers because you can't get at them with a screw driver with the circuit boards in place. There was a couple of different versions of the metal work and they each have their challenges to get at the fans. For that reason I can't really give a step by step explanation. You'll just have to wing it. The fans that I've used with great success are:

Sunon ME80251V2-000U-A99
Sunon ME60251V1-000U-A99

Both were readily available on Digi-Key when I last bought them.

I hope that helps.

Posted by Carsten Kurz (Member # 5396) on 05-05-2018, 12:46 PM:

I assume opening a DSP100 will issue some sort of tamper event? How do you clean that? A friend received a DSS/DSP100 combo. The DSS100 was extremely filthy and he cleaned it, but what about the DSP100? He is anxious to trigger a tamper event he will not be able to get rid off.

- Carsten

Posted by Steve Guttag (Member # 268) on 05-05-2018, 01:09 PM:

Nope, opening the cabinet does not trigger an event (on either. Ever noticed that most of the servers have a cabinet tamper switch physically there but it isn't wired to anything?

I've been in both the DSS100 and DSP100 and ever triggered an event.

Posted by Stephan Shelley (Member # 8587) on 05-05-2018, 01:12 PM:

You can remove the top of the unit. It will log the fact that it has been opened but will not require to be cleared. As long as one is careful not to disturb the decoder board(s) you will be okay. Make sure to reinstall the cover. Will not work with it off. Nothing to clear. If you do disturb the decoder card(s) they will trash the certificates and will need to be reflashed by one that has the authority to do it. Not something that can be done in the field. Don't know if there is anyone still doing it for the DSP 100 or not.

Posted by Carsten Kurz (Member # 5396) on 05-05-2018, 01:26 PM:

Thanks. I told him to be extra careful about the electronics and only shovel out the most obvious dirt.

- Carsten