New 722 Cooling Mod

[primestar31]

As far as I know, you can't buy any spare parts for E* receivers. I got the 222k from a retailer dissolution for free. It's brand new in box. I just used the cover from it. I was lucky to get my hands on it, because they were taking lots of stuff to the landfill. I rescued that unit.

Have you gone to the landfill, and rescued all the rest of the stuff!!!

Wow, I'd be there in a minute, if I lived close by.

 

[ralfyguy]

Have you gone to the landfill, and rescued all the rest of the stuff!!!

Wow, I'd be there in a minute, if I lived close by.

No, it was mostly boxes from newer receivers, with older receivers in it. Most likely customer upgrades. Old Legacy LNBF's, tons of crappy coax and tons of crappy coax crimp connectors. I have no idea, how this company did decent installs with this stuff. The ViP222k I rescued had the silver 6.3 remotes in the box, so sadly I didn't get th new 21.0 remotes. But the receiver is brand new, I hooked it up and it went straight to the satellite setup screen and had L050 SW on it, like it came from the factory. I wonder if someone would get it activated. If somebody is interested, let me know, as I have no use for it. But remember, it has a ViP722 cover on it.

 

[Grandude]

I think I'll buy a sheet of perforated aluminum and see if I can bend it in the right places to make a new lid for my 722. Shouldn't be too hard to do. Maybe I can put to use some of the lessons I got in sheet metal class back in the 7th grade. Lets see, that must have been about 60 years ago.

 

[Agonizing Fury]

Keep in mind that although you've lowered the temps of your hard drive with this mod, you may actually be increasing the temperature of other components. the reason the 622/722(k) have so few vents is that they have a cooling fan. The fan is set up so that cool air from one side of the receiver is pulled in and hot air is blown out the other side. This cools the entire interior by limiting where air can get into the case and causing fresh air to be moved across all components. By adding extra vents, air is only moved right by the fan. any components on the opposite side of the receiver from the fan are now only getting cooled by convection, when they are designed to be cooled by the air moving past them from one side to the other. The 222k has a case with lots of holes because it has no cooling fan, and therefore the extra slots increase convection.

 

[ralfyguy]

Keep in mind that although you've lowered the temps of your hard drive with this mod, you may actually be increasing the temperature of other components. the reason the 622/722(k) have so few vents is that they have a cooling fan. The fan is set up so that cool air from one side of the receiver is pulled in and hot air is blown out the other side. This cools the entire interior by limiting where air can get into the case and causing fresh air to be moved across all components. By adding extra vents, air is only moved right by the fan. any components on the opposite side of the receiver from the fan are now only getting cooled by convection, when they are designed to be cooled by the air moving past them from one side to the other. The 222k has a case with lots of holes because it has no cooling fan, and therefore the extra slots increase convection.

You might have a point there, nevertheless the whole thing feels alot cooler to the touch on the top. The built in fan is integrated in a duct, and it actually blows straight on the HD. There's almost no moving air to the feel to the left of the HD, in fact that very little air you still feel is rather warm. The power supply components to the left of the HD kept the surrounding housing quiet hot. It still is very warm in that area, but not as bad as before. BTW, the temp dropped another 2 degrees to 107F.

 

[AVMe]

I figured that the reason the 722's top cover does not have ventilation holes is to better muffle noise coming out of the receiver. These receivers need better ventilation but they are quite noisy.

For those who replaced the original sealed top cover with one that has vent holes, did your receiver get louder?

 

[ralfyguy]

The HD seems to emmit a tad more noise, but not much. This doesn't surprise me though. The HD is right underneath the cover. I prefer the cooler temps.

 

[bebop]

I figured that the reason the 722's top cover does not have ventilation holes is to better muffle noise coming out of the receiver. These receivers need better ventilation but they are quite noisy.

For those who replaced the original sealed top cover with one that has vent holes, did your receiver get louder?

How did you 'figure' that out?

 

[TheKrell]

If noise is of no concern, we could simply remove the top without reinstalling another (perforated) one.

 

[Smith P.]

Keep in mind that although you've lowered the temps of your hard drive with this mod, you may actually be increasing the temperature of other components. ...

You're almost correct with a few omitted important technicalities - I wrote a lot about 622/722 airflow "design" and issues with it in that main thread " Average 622/722 Temperature thread, Is your's Hot? "

 

[bebop]

If noise is of no concern, we could simply remove the top without reinstalling another (perforated) one.

But then you have open to the air/environment high voltage capacitors and it would shock the heck out of anyone that accidentally touched one. Not to mention anything accidentally falling in/on the unit. Bad idea, IMO.

 

[TheKrell]

What high voltage capacitors? I would not expect any higher voltage than needed to power the switches and LNBs.

 

[Smith P.]

Check switching power supply schematics - you'll find 110 V AC easily ! As to particular DVR - look at biggest cap with 400V label and around a transformer.

 

[bebop]

What high voltage capacitors? I would not expect any higher voltage than needed to power the switches and LNBs.

The capacitors in the picture linked here (lower right of picture) are actually located in the back left of the receiver as you look at it from the front:
http://www.satelliteguys.us/attachment.php?attachmentid=34467&d=1235680772


The capacitors get to 'high voltage' not because there is a higher voltage coming into the receiver from the electrical outlet compared to normal, but because they take that power and charge up the capacitors to use in powering the receiver as a whole. They are like batteries, but in this case AC instead of DC and they'll shock the heck out of you if you touch the top of one of them while they are charged. Do not try that, as it will hurt you and potentially damage your receiver.

The circutiry inside the receivers need protection and the cover is the most sensible method for that. I think that anyone who leaves the cover off of the receiver should expect an accident, since you can't always control who is reaching around there, or what things might be flying through the air. I mean, even if a fly was buzzing around your home and landed on one of those capacitors, he'd fry and cause a mess. People should not allow live electrical equipment out in the open.

 

[TheKrell]

Fooey. I fool around inside of live, low voltage equipment (such as satellite receivers) all the time, and I've never zapped myself even once. P. Smith is probably right that you can locate 117VAC pretty easily; that should be the highest voltage anywhere inside your Dish Network receivers. But usually the 117V is fully insulated all the way into the transformer.

Switching power supplies... That's a possibility for higher voltages depending upon how it's engineered, and what it's doing. Florescent light bulbs need high voltage, but satellite receivers do not. Anyhow, I think these power supplies are typically entirely enclosed inside of their own metal box, similar to a PC power supply. So taking the lid off a 722 would still not expose anybody to more than 25V or so. You would not feel anything, (assuming you have dry skin).

But as bebop says, you don't want objects falling into the receiver either, since (safety aside) the receiver could be damaged. What I thought you (bebop) meant was high voltage, e.g. such as exists inside CRT TVs. Just because a receiver is associated with television, it does not follow that there is high voltage inside the receiver itself. The old CRT color TVs used to generate not 25V but 25,000V. That's high voltage! You could definitely get zapped, if not X-rayed, by that old tech stuff, whether or not your skin is dry.

I have never disassembled an LCD TV. Anybody know what kind of voltages are inside? Edit: most have florescent backlights, so I imagine they too have 1000's of V inside.

 

[Smith P.]

Not sure about big LCD screens, but 23" monitors - around 250 V.

No, the receiver's power supply parts doesn't covered by metal shields - they are cheap for design.
So, some contacts from top of PS PCB could be touched by your fingers to get zapped ( been there many times - no biggy if you are wear sneakers and not wet ). Also, max output voltage in such PS is 18..30 VDC.

 

[bebop]

Fooey. I fool around inside of live, low voltage equipment (such as satellite receivers) all the time, and I've never zapped myself even once.

You probably are more careful than someone who doesn't know what they are doing. I guarantee if you pull the cover off of a live 722 receiver and put your hand on top of the large power capacitor that it will shock the heck out of you.

P. Smith is probably right that you can locate 117VAC pretty easily; that should be the highest voltage anywhere inside your Dish Network receivers. But usually the 117V is fully insulated all the way into the transformer.

The capacitors do charge up and are rated higher than 120VAC. The large one I was talking about near the 120V input is rated at 200V and 1000uF.

So taking the lid off a 722 would still not expose anybody to more than 25V or so. You would not feel anything, (assuming you have dry skin).

That assumption is wrong, see above and Smith's post. If you steer clear of that capacitor, you shouldn't feel anything...

But as bebop says, you don't want objects falling into the receiver either, since (safety aside) the receiver could be damaged. What I thought you (bebop) meant was high voltage, e.g. such as exists inside CRT TVs. Just because a receiver is associated with television, it does not follow that there is high voltage inside the receiver itself. The old CRT color TVs used to generate not 25V but 25,000V. That's high voltage! You could definitely get zapped, if not X-rayed, by that old tech stuff, whether or not your skin is dry.

The satellite receiver has markings on the circuit board that say 'High Voltage' and there are some lightning bolt symbols around it. This is to indicate to stay away from it. You basically don't want to mess with a capacitor when it's charged.

There are different meanings of 'high voltage' and this one relates to the receiver and what the circuit board says.

Take care.

 

[Smith P.]

"High voltage" mark usually noted for circuits with voltage higher then 24 V or so.

 

[bebop]

"High voltage" mark usually noted for circuits with voltage higher then 24 V or so.

Yeah, but I doubt anyone wants to get zapped with 200volts from the power capacitor under the 722 lid. I didn't think we were going to consider everything else out there that is actually high voltage.

12k Volt electric lines are 'high voltage' also, but they have nothing to do with sat receivers...

 

[Smith P.]

When I'll have time I'll measure the caps, etc inside of 722.