View Full Version : Temperature and fan issues...
12-22-2005, 12:08 PM
I recently replaced both drives in my Sony SVR-3000 because of imminent hard drive failure. Before the replacement, I was running the original Maxtor 80GB drive and a WD 120GB SE drive. Now I have a pair of WD 120GB SE drives. Before the upgrade, I believe my internal temperatures were in the High 30's to low 40's C. After, I'm seeing an average of 49-51 C. This seems high to me, so I did my homework, and attempted to replace the stock fan with a more powerful fan. I tried two different model fans, and have them hooked up via a 3-4 pin power connector.
The fans don't seem to be pushing much (if any) more air than the stock fan was, although they are rated considerably higher for CFM. The average temperature using the first fan was actually a degree or two higher, and this prompted my purchase of another fan, which dropped the temp back down to about 48 C.
So I'm wondering, is it possible the fans are running in a lower speed mode than they are capable of?
Why are my temperatures so much higher than before adding the new drives? I would imagine that the higher temps will shorten the life of the drives.
Besides lifting the Tivo up on bottlecaps or some such, or drilling holes in the cover, does anyone have any thoughts on how to get the temperatures down a bit?
12-22-2005, 12:34 PM
Some Tivos drive a 12V fan with 7v, making it run slower.
Do you have a multimeter?
If this is the case, then you could tap the hard drive's power cable to get a full 12V. But it'll be quite a bit noiser.
12-22-2005, 01:01 PM
As dagap mentioned, the main problem with higher CFM fans is that the noise will increase which is unacceptable to many people.
These TiVo units are simply not designed to handle the heat generated by 2 drives that are being written to every second of every day, 24/7. They have marginal ventilation that is not even adequate for a single drive if the ambient temperature is on the warm side.
In my mind, there is simply no choice but to modify the box for better airflow using a large quiet fan. Otherwise, the hard drives will be subjected to operating temperatures that are too high and will imminently fail sooner rather than later.
12-22-2005, 03:24 PM
I'm already running off the Hard drive power supply, so I'm not sure why the fans seem to lack power.
I'm not sure I have the skills or tools to modify the box. Is there anything else that can be done?
12-22-2005, 05:36 PM
The SVR-3000 suffers from the same cooling problems as Series 1 DirecTiVos. The principle used is to push air from the mobo side of the unit over into the power supply. In theory, this pushes warm air out the bottom vent holes on the right, while drawing in cool air from the left vent holes. There are two problems with this:
1) The "barrier" between the mobo and the power supply has lots of holes, allowing air to flow back into the mobo part of the case
2) The warm air exhausted out the right hand side, flows back under the unit and into the left hand vents
The solution is to open the case, and seal the holes between the two sides of the case. This can be done with duct tape or hunks of foam. Then, attach a strip of thin (1/4") window insulation to the top of the barrier so that it contacts the case when the lid is replaced.
Finally, apply a stip of the insulation down the middle of the underside of the case, from front to back. This will prevent the backwash of warm air under the unit to the air intakes.
These steps will lower the temperature of the TiVo anywhere from 3° to as much as 10° depending on the air flow around the unit.
12-23-2005, 12:14 PM
That sounds very doable to me. Thanks for the information. I'll give it a try when I get some free time, and let you know if it made a difference.
01-09-2006, 01:13 PM
I made the modifications recommended by Dan Collins on my Tivo and I thought I would let everyone know what kind of results I had.
Before I did anything, I got the idea to move the Tivo to the bottom shelf of my equipment rack. The rack is open on all sides, so I didn't think it would make that much difference, but it was on the shelf above the cable boxes, which give off quite a bit of heat, so I figured "why not?" This resulted in a 4-5 degree difference in average temperature right off the bat. I went from 49C or so to about 44-45C on average. The lesson here: heat rises.
Still not satisfied, I followed Dan's instructions regarding blocking the holes in the barrier, and adding the weather stripping. I have since been averaging about 41C! Overall, I dropped my Tivo temp about 9 degrees, and I think I'm in a pretty good range now. So thanks to all for their input, especially Dan Collins.
While I had the cover open, I tried a little experiment: I still believed that the fans I had were running at lower speeds than they should have been, which had prompted me to buy stronger fans, until I had about three different ones. They all seemed to be about the same in power, and about the same loudness, and this did not make sense. I was running the fans off of the hard drive power cable using a 3-4 pin connector. The adapter had 3 wires. I swapped this adaptor with one that came with one of the replacement fans I purchased. The new adapter was also a 3-4 pin but only had 2 wires. When I plugged in the various fans, I couldn't believe the difference. Now they were running at full power! They were also incredibly loud. In my quest to lower the temperature, I ended up with much louder and more powerful fans. Way too loud to use in the Tivo. I replaced the 3 wire adapter, and all is silent now. Given this, I think I may be looking to replace the fan again. I did some research, and learned that the stock fan in the SVR-3000 is rated at 23 Db, for 13.7 CFM of airflow. Assuming it was running at capacity (I wasn't able to check as the stock fan had a special connector to plug into the motherboard) I did some research into some other fans that might be more powerful at near the same Db levels. I think the Adda AD0612MB-A70GL at 24 Db and 18 CFM looks like a good candidate for a quiet, more powerful fan. At 41C, though, I may leave well enough alone.
Thanks again for everyone's input.
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