# 942 Cooling Fan Speed?



## XXL (May 19, 2005)

Having used a 942 for a year now, I’ve noticed that the cooling fan on the bottom of the unit frequently speeds up when recording or playing a program and sometimes does this in standby mode. I do understand that this is normal.

However, for the past couple of days the cooling fan continuously runs at high speed, even in standby. The 942 is not enclosed in a cabinet.

Doing a search for info on the 942’s cooling fan on this forum, I found several threads that mentioned overheating conditions. In a thread started by Gutter back on May 25, 2005, he put ¼” spacers under the feet of the 942 to aid cooling. (He had an overtemp warning of 147 degrees.)

I took Gutter’s idea and put 1” thick rubber spacers under the feet on my unit. The temperature drop of the 942’s housing was VERY significant! The heat given off from the vents on the left side was greatly reduced and the exhaust fan on the bottom almost feels like it’s now blowing cold air.  

However, the cooling fan is still continuously running at high speed (in standby) and is quite audible from our normal seating location in our HT. Will check the internal temperature when I fire the unit up tonight.

Otherwise, my 942 works GREAT!

Thanks to all the contributors on this excellent forum!


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## Jon Spackman (Feb 7, 2005)

Thanks for bringing up a great tip from a long time ago. I have kept all my dish receivers spaced up with cork/rubber spacers about 1" tall. I also have a couple of small pc types fans running 24/7 to blow away the heat generated by my 942's. 

It is good to mention the cooling benefits of some kind of spacers to those who were not reading this forum a long time ago. 


As for your fan running full steam all the time, have you tried a power cord reboot? Does the fan run full hog when you are viewing tv or just in standby?


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## XXL (May 19, 2005)

Jon,

Sounds like you were already clued-in to this cooling tip. Cool! (Pun intended)  And yes, forums like dbstalk.com contain so much info from so many people that it's good to go back in time every so often using the search function.

To answer your question, the cooling fan has been running at high speed continuously for the past two days, both when "on" and in "standby". It hasn't changed speed / audible output for two days. Previously, you could easily hear it cycle slow / fast.

I did take your suggestion and performed a power cord reboot. After plugging the 942 back in, the fan ran at high speed for 20-30 seconds and then was quiet. A green light on the front panel came on for a few minutes and I could also hear the HD spin up. After a few minutes, the green light went out and all I could hear was the HD.

Checking underneath the 942, I could feel no cooling fan discharge. I propped the unit up and looked -- the cooling fan blades are not turning! I've never seen or heard this before on my 942.

The left side is a little warm, but significantly cooler than it was before "putting it up on blocks". :lol: 

Our HT is 67 degrees right now (it's below ground level), so I'm guessing that the cooling was so effective after giving it more air that the fan doesn't need to run.  I thought that the cooling fan was supposed to run all of the time, changing speeds as needed to prevent the internal temperature from exceeding a certain limit.

Sorry, I don't have a TV on right now (I'm too busy chasing moles around the yard), but will see if turning the unit on tonight causes the cooling fan to kick on. Will also check the temp under diagnostics.

Thanks for your input! I really appreciate it!


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## lakebum431 (Jun 30, 2005)

Yep, very good tip! I've also had mine set up on spacers for quite awhile. Just for future reference, if something is acting funny with any of the DISH boxes, a soft reboot (hold the power button in) or a hard reboot (pulling the power cord) will fix it most of the time. These are honestly the best two trouble shooting tips that I have.


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## XXL (May 19, 2005)

lakebum,

Thank you too for the tip. It appears to be a very easy fix for a number of wacky electronic maladies with the 942.

Cheers!


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## dogday (Dec 6, 2005)

Mine has been running at a high speed the past couple days as well. 

It gets plenty of ventilation as it sits on a wire mesh rack with a few inches below to the DVD player which is rarely on. The unit doesn't feel the least bit warm on any side.

I left it unplugged for about 12 hours overnight and it was running back in it's original state for a few hours. But it has since returned to the high speed and volume.

Is there a chance that the latest software update could have caused this? The timing is suspect. 

Any thoughts would be much appreciated!


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## lakebum431 (Jun 30, 2005)

I don't think it is the software because neither of my 942's are having this problem. Now that Summer is here, how warm are you keeping it in your house? It may just be that the surrounding air temperature is warmer than before which is causing the fan to blow more than it had before.


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## Jon Spackman (Feb 7, 2005)

Neither of my 942's have their fans running full hog as well. I do have a couple of computer fans blowwing across the left side of my 942's 24/7.


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## wkomorow (Apr 22, 2002)

I'm glad you posted this, I thought I was having a problem with my receiver. Just after the L287 upgrade, I noticed my fan was running continuously. This lasted a day or two. It was so noisy that I could hear it in the upstairs bedrooms (the receiver is in the downstairs living room). For whatever reason it's fine now. I think it was related to the software update; temps have been in the 50's at night here, so I can not image that the receiver was overheating.


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## dogday (Dec 6, 2005)

while it has been a bit warmer outside, the inside temps aren't any more than usual. The unit itself also does not feel the least bit warm - neither the case, nor the air blowing out of the vents. The fan is also running at a continous rate, rather than the usual occasional rev up and slow down.

I'm not surprised that it's not happening to everyone, but I'm ever so slightly comforted that I'm not the only one.

Is it coincidence that I got the call the day before the fan change to upgrade to the 622?


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## XXL (May 19, 2005)

Sounds like (some) others are experiencing the same cooling fan condition that I originally mentioned above. Thanks for your feedback!

Like dogday, I too wonder if it is 287-related...

What's now weird is that the cooling fan either runs at high speed or is totally off, both in standby and when on.

When the fan is roaring away, the entire box is cool to the touch.  When the fan is off, the left side is warm.

Audio / video = no problems.

Regards


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## RBenson (Jan 25, 2003)

My 942 has had this problem since the download too. Every morning the fan is roaring away but goes away with a hard reboot. Next morning, after an update it is running at full speed again. I hope they are aware of this and are trying to fix it. I wish they would just leave things alone when things are working OK. I just want to watch tv and record something once in a while. Everything was great until 287.


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## sixbears (Jan 19, 2005)

I too have noticed that my 942 fan is running all the time. I unplugged it for 12 hrs , then placed it on 2" spacers and plugged it back in. It booted up and all was well (no continious fan operation). After work I came home and the fan was running all the time. 942 was in standby all day.

Sounds to me due to the number od complaints from other users that this must of been caused by a software update. So until they fix it, I will have to reboot it when I want to use it.


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## Jerry 42 (Feb 25, 2003)

I am having the same fan problem but on only one of my 2 - 942s. 
I have 1/2 inch bumpers under each for all the time I had them - about 18 months. The high fan speed problem just started to ocurr about a month ago. 
After reading this helpful thread I did a power cord restart and it seem to fix problem but I do not know for how long yet. (PS did a power button reset first but it did not fix it need the power cord reset)


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## Jerry 42 (Feb 25, 2003)

Update -

The power cord "fix" of last night was unfixed this morning. Doing a power cord reset this morning seems to again "fix" the problem. As noted by others it would seem to be in some way related to the 3 AM EPG download. 

Still find it odd that it only seems to affect only on of the 2 - 942s (always the same one.


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## wkomorow (Apr 22, 2002)

Mine was quiet for several days., but it started to whirl again (can't be the temp -it is really cool here).


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## Jerry 42 (Feb 25, 2003)

Based upon the fact that only some of the 942s are having this problem (i.e. 1 of my 2) it may be a problem with a certain group of sensors that was set off during one of the software updates.

The problem (issue) is back on the 942 that had the problem. The other 942 never had/has this problem.


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## XXL (May 19, 2005)

Thanks for the additional input, folks. That's interesting about Jerry 42's two different 942 units behaving differently. Maybe E* can use this info to correct this situation.

Some of us are more sensitive to whirring / whooshing noises than others. Some HT enthusiasts even purchase front projectors, amps, etc. that are the quietest available so as to not detract from the quieter passages in movies and music. When my now-noisier 942 is churning away, it makes FAR more noise than my front projector or my fan-cooled amp. This is really distracting!

Enclosing this 942 wind machine is certainly possible, but I’m hoping for an L2.88 fix.


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## LtMunst (Aug 24, 2005)

I noticed the fan running constantly on my unit also. This is a new phenomenon, had the unit a year now. Looks like Dish changed the parameters for what triggers the fan to come on.

Not sure it is necessarily a bug. Could be an attempt to help with overheating issues some have had. It does not bother me, but I could see where those with a 942 in their bedroom could get annoyed.


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## dogday (Dec 6, 2005)

any updates on this lately??

I've been out of town for the past several weeks and came home to find my fan still running full-tilt all the time (except for the occasional stoppage in middle of the night when the box is off - during software downloads perhaps?).

I hate having to call tech support, but getting a bit tired of the noise.


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## Jerry 42 (Feb 25, 2003)

I found a work around - not the best answer but it does work.

I brought a small very quiet computer case fan that operates on 12 DCV at .08 ampere. From the various old DC transforms (used a 12dvc 300 mA) I have around I cut the DC side output wires and connected the two fan wires to the the transformer. (note if the fan does not work switch the two wires as poles are important here) 

I placed the fan outside the left side of the 942 case by the vents with flow going away from 942 and immediately the 942's fan speed dropped to the lower quieter rate. 

This my not be the answer that everyone is looking for - but the exterior fan and the lower 942 fan noise together is substandially quieter than the 942's fan running at the higher speed. 

This works with both my 942s - one fan each. I got both fans as package for less than $12. Just be sure to check the "db" noise ratings of the fan(s). 

Just a suggestion.


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## Jon Spackman (Feb 7, 2005)

Maybe this is why I have never heard the internal fan as I have had two computer fans with a 12v transformer blowing across my 942's since day one.

Excellent post and might be a fairly inexpensive solution for some until it corrected via software (if that is a possibility).


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## dogday (Dec 6, 2005)

Thing is, with mine it definitely not running hot. The fan is on all the time, regardless of whether the receiver is on (I know it's technically always on, but you know...).

There is plenty of ventilation on all sides of the unit and the room temp is kept nice and cool thanks to a/c. It simply seems that the fan is just on - and the timing corresponds exactly with the last sw update.

guess it's time to call tech support. what time is it in India??


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## Jerry 42 (Feb 25, 2003)

dogday

My 942's were not running hot either. There is more than 4 feet of space on front and both sides and I have them sitting on rubber spacers that makes an extra 1+ 1/2 inch clearance under the units. I do not know the final answer but perhaps air is not moving from inside the 942 case to outside fast enough and the exterior fan pulls out extra air from the 942s. 

One 942 is in the bedroom and my wife was saying how much noise there was late at night. Now with the fan the noise 80% quieter. 

PS before going the fan route I called tech support and even got to supervisors in US. Their response on the fan noise was "its normal". So good luck with TS. My guess is 942 fixes are less important to DIsh now that the MPEG 4 boxes are out and they want you to trade up.


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## Jon Spackman (Feb 7, 2005)

Jerry 42 said:


> My guess is 942 fixes are less important to DIsh now that the MPEG 4 boxes are out and they want you to trade up.


This couldn't be further from the truth. Dish is still very interested in the 942 and will take care of this if it turns out to be software related. They care and are on top of things.


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## wkomorow (Apr 22, 2002)

Jerry -

Any chance that your mini-fans are creating white noise that is absorbing some of the fan noise from the 942. BTW, my 942 fan has been fine over the last few days.


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## Jerry 42 (Feb 25, 2003)

wkomorow

Anything is possible. I my case the high fan speed noise stopped and the internal fan speed/noise when down to the old speed/noise about 2 seconds after I turn on external fan. BTW the external fan noise rating is 12 dbs which is very low so it is unlikely to cover any other noise, 

It may be the air flow/movement inside the 942 some how increase and that self corrected the internal 942 speed control. I was just thinking that this "issue" seemed to arise around the time of a previous Dish solfware, BUT it was also the time our general temps went up as we approached spring/summer. Perhaps that had some effect on the 942 internal temp fan controller. Do you / anybody have their 942s near an a/c vent that might cool the outside air enough for the 942?

An other idea which I have not tried as I not sure its wise or safe for the components of the 942, is to use compressed air and blow the air into the 942 and see if it cleans out and dust etc that might be blocking something and causing the internal fan to run at the high rate. 

As I have had both 942s since the first month they were released and never had this "issue" before, I do not believe "its normal" as the CS supervisors said. The 942s are IMO good machines - I replaced 2 TiVos with them. I want to keep them going and operating as they did when I first got them. 

Good luck with whatever to do.


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## scn101 (Jul 11, 2005)

Over the past month I've noticed that my 942's fan often runs at full speed. The box is very cool to the touch and is in an open area. I've had the 942 for over a year and its never run the fan at full speed continuously. It is mounted on 1/2" spacers for better airflow.

If I do a soft reboot or a power line reboot the fan speed restarts at full speed for about 20-30 seconds and then slows down to a "normal" speed. It remains at a variable low to medium speed for a day or two and then locks on high speed again. I usually notice the high fan speed first thing in the morning, so I think it locks on high speed sometime during the early morning hours.

Since the box is cool I suspect either a temperature sensor failure or perhaps it is software related. Anyways, I think Dish might want to look into this.


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## lakebum431 (Jun 30, 2005)

What are your high, low, and average temps? Go to menu 6-3-Counters to check.


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## scn101 (Jul 11, 2005)

lakebum431 said:


> What are your high, low, and average temps? Go to menu 6-3-Counters to check.


Fairly cool I think at: 118F High, 93F Low, 111F Average


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## lakebum431 (Jun 30, 2005)

Yeah, those look good. The fan should not be running full time. Looks like it might be time to replace that sucker with a brand new 622


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## scn101 (Jul 11, 2005)

Well I finally had enough of listening to my 942's fan sounding like a jet engine. The only way to have the fan return to a normal speed and sound was to either do a power cord or soft reboot. The fan would then settle down and run normally for a few hours but always returned to high speed. This process was getting old and kind of annoying.

The case was cool to the touch. The 942 was on a open shelf, on riser spacers, in a cool room with no heat sources anywhere near it. No way was the fast fan needed. Besides, it never did this over the previous 12 or so months. Something must be wrong. In addition, I was having issues with the 942 responding to the remote, sometimes it would, other times it wouldn't.

So I decided to open the box. Hey, maybe some dust was clogging it? Opened it, no dust, no dirt. But I did find a TO-220 package split open down its middle. It was a LM340T12, a 12V postiive linear voltage regulator. VR9 on the PCB. As luck would have it, I had a 7812 spare (part of my hobby repairing pinballs and pretty much identical to a LM340T12). I removed the offending device and noted that it had almost no thermal grease between it and its heatsink. This may explain why it failed, simply got too hot. Put some thermal grease between it and the heatsink and soldered in the 7812. Put it all back together as I had to completely remove the motherboard, harddrive, and power supply card.

That was three days ago. Ever since the fan has been running between low and medium speeds. No more jet engine sounds. And the remote is working properly again. Anecdotal, but the two issue may of been related? I can't be sure because I don't have the schematics to the 942. If anyone does, please send me a copy.

Not sure if my 942 was an isolated incident but I thought I'd share the experience.

Happy again with my 942.


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