Film-Tech Forum ARCHIVE: DSP100 fan replacement

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Posted by Leo Enticknap (Member # 534) on 07-25-2019, 09:17 PM:

Just been contacted by a customer: Show Manager is saying "Show Player: A fan has failed (fan error)". Advised her to point the large stand fan in the booth at the server rack at point blank range, and hopefully that will get her through the evening.

Does anyone know what generic model of fan(s) goes in a DSP100, and/or where I could order one for quick delivery? I'm guessing that Dolby won't be able to supply them anymore, given that official support for this model ended quite some time ago.

Edit / afterthought: this is at a drive-in, where the temperature in the booth in not much less than that outside (around 100 at the moment), and the air quality is garbage, so I'm not surprised that a fan has gone out. As luck would have it, I'm due there for planned maintenance next week anyways, and so if I can get hold of them in time, I'm going to try to replace all the fans in both the DSS100/DSP100 combos there.

Posted by Steve Guttag (Member # 268) on 07-25-2019, 10:32 PM:

For the DSP100:

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

(2 pieces)

Note, you'll need to splice the new fan wires onto the existing ones that have the plugs/sockets to interface with the motherboard. It isn't a bad operation but you will need security bits to take the DSP100 covers off (torx with the center pin, as I recall)

The DSS100 fans can be a PITA. You need angled pliers to hold the nuts while screwing in the bottom screws. Otherwise, you can try tapping the fans and skipping the nuts.

Posted by Leo Enticknap (Member # 534) on 07-25-2019, 10:49 PM:

You're a life saver, Steve; very many thanks. Will remember to pack angled pliers and/or some self-tappers.

Posted by Scott Norwood (Member # 30) on 07-26-2019, 09:05 AM:

It looks as if this is just a standard 80mm computer fan, without the third wire for the tachometer signal. Maybe someone can confirm that. If so, you can probably get one locally with similar CFM specifications for about $10. Just make sure that the air blows in the correct direction. Most cases are designed to have the fans blow front-to-back, but this is not universally true.

Posted by Steve Guttag (Member # 268) on 07-26-2019, 10:20 AM:

I don't think there is anything special about the fans either. I want to say we found fans that met the size/cfm spec. Fans have a way of going out of production.

The DSS100 fan we've used (out of production now too) is the KDE1209PTV3 (Sunon).

It is a 92mmx92mmx25mm 39cfm. It wasn't too uncommon to see one or more of the DSS100 fans not spinning (some you could jump start).

The DSP100 fans are stacked in line with each other.

Posted by Leo Enticknap (Member # 534) on 07-26-2019, 11:09 AM:

Thanks again, folks. This looks to me like it'll work for the DSP100. 59 CFM is probably overkill (Amazon has several alternatives for around $5 less, with CFM figures in the low to mid 40s), but given the ambient temperature in that booth, better to be safe than sorry.

As for the air direction, I've encountered that gotcha before! Some computer fans have an arrow on the side, but if they don't, you have to look at the direction of the blades. I have to do this just infrequently enough that I need to look up a diagram online whenever I'm faced with this situation.

This is something to tread carefully over when doing a complete fan swap out in an NEC900. Most of the fans don't have arrows, and it's not even totally reliable to go by the side that has the label on it. It can be on the other side on the replacement to the one you pull out.

Posted by Greg Routenburg (Member # 1742) on 07-26-2019, 01:11 PM:

I've changed a ton of these fans over the years. The ones that I've used are:

The front fans were Sunon MB60251V1-000U-A99.
The back fans were Sunon ME80251V2-000U-A99.

Sunon changes their part numbers all the time but anything 12V with those approximate specs will work. They're just standard two wire fans.

The front fans are a real PITA to get at and Dolby doesn't have an official method for changing them. There were several versions of the metal work for those units and each version requires you to hold your tongue just so in order to get the fans out. Regardless of the version, the best way I've found to change them involves removing the two power supplies and the power supply back plane. You need to remove the power supply support that runs down the inside of the unit and then you can carefully remove the front fans while still mounted to their bracket.

The only thing that Dolby told me was that under no circumstances can you disturb the media block. Active securty and all that.

Posted by Leo Enticknap (Member # 534) on 07-27-2019, 11:37 AM:

Fans ordered and arriving tomorrow - thanks again, everyone. The DSP100 in question worked OK through last night with a stand fan blowing at the rack, so with any luck it'll be OK until I'm due there on Monday.

Posted by Leo Enticknap (Member # 534) on 07-29-2019, 04:35 PM:

Replacements done and all is happy. The fan that had stopped working had succumbed to a thick layer of popcorn oily, gungy shite, that eventually overcame the power of the motor to prevent it from sticking the blades to the side of the housing. Yeughh. A gnarly black cloud rose up from the thing as I blasted it with the Datavac. There probably should have been a Prop 65 warning label on it! The other screen's DSP100 was almost as bad.

Angled pliers weren't needed, because in these units, there were no nuts on the end of the long bolts that go through both fans. Instead, there was a 92mm square steel plate with a cutout for the fan intake, and four threaded holes at each corner, that sits on the innermost fan. Once I'd got the top two bolts started, the bottom two wiggled in with hardly any argument.

Presumably Dolby moved to this arrangement because lots of nuts were being dropped and getting lost under the media block. It certainly saved a lot of fiddling.

Steve - thanks again for the heads up about needing security bits and wire splices (I'm a big fan of these solder seal splices for this sort of thing). Needless to say, the replacement fans had slightly different connectors to the old ones that were pulled out. It would have meant a return trip if I hadn't brought them.

Posted by Steve Guttag (Member # 268) on 07-29-2019, 06:19 PM:

Leo...if you check my post, the angled pliers are for the DSS100 (you mentioned that you were going to change its fans too). The fans in the rear, in particular are prone to failure and it is tough to hold the lower nuts without the angled pliers.

The fans you changed are indeed easy enough so long as you have the security bits and are prepared to solder/heat shrink (what I've done).

Posted by Leo Enticknap (Member # 534) on 07-29-2019, 11:26 PM:

Original post was a bit ambiguous, and I didn't have time to do the servers as well (sorry). The fans at the back actually didn't look anything like as bad as the ones in the DSP100s - I'm guessing, due to differences in the airflow within the cases.

Something to keep in mind for the next scheduled maintenance visit, though it's anybody's guess how long those DSS100/DSP100s will remain in service for (and therefore, how much heavy maintenance it's worth doing to them). It could be another few years, but if a media block dies tomorrow, that's it. Both sets were manufactured in 2007 and have been in continuous use ever since. So, judged by the standards of typical computer hardware, they have already done pretty well and would be considered by many to be EOL.