Originally Posted by christoofar
Since I installed my recently aquired/repaired 4520 into my modest system, I've been completely overjoyed with it's performance, such a big step up from what I had before.
This morning I had it up & playing some music as we had breakfast (SomaFM Lush, over Asus Chromebook/Kodi) when the AVR suddenly just shut off, and red blinking standby light. I walked over & hit the power button, and the blinking stopped, but still no power up. Hit button again, it came back up & continues playing as before. I have the AVR in a lowboy Ikea media stand, I have 2 wood pieces under the feet to elevate it a bit more to allow airflow, and there is a 1.5" gap both above & below it on the shelf. I stuck an instant read thermo I have on top for a while & it indicated approx 140F. Does that seem high? Though about getting some additional cooling fan on top to pull more air out. Ambient temp in room is not hot, AVR was playing at low volume, so it wasn't being driven hard.
Just wondering if there's any suggestions on cause or could it just be an anomaly. I've been using it daily ever since I got it, this is the only time this has occurred.
God ,I hope this isn't an indicator of more problems, I can't afford another $300 .
From the owners manual Page II, see attachment:
Note that 12" is recommended in all directions but the bottom.
Personally, as noted in a prior post, I use a dual fan unit with a thermostat controller set to come on just above room temperature.
I don't know why your unit shut down, even so, I would not run my unit without the fans as I only have ~4" of top clearance while the back and sides are open. My work experience taught me that for every 10 C rise in temperature cuts the time in half of chip failures, so, IF there was a defect desined to fail in 1,000 hours at 25 C, raising the temperature to 35 C could cause it to fail in 500 hours. IF I have math anywhere close at 140F you are around 65C, about 35 C above 25 C. Thats a 10 C rise 3 plus times, i.e. at 35 C failure pulled in to 500 hours, 45 C to 250 hours, 55 C to 125 hours another 5 C to 60 C somewhere under 100 hours to trigger that defect failure. Even if there is no inherent semiconductor defect you are aging the silicon chips at a greatly accelerated rate. Just my opinion, and may be of no consequence today as I have been retired for some time. I prefer to be on the conservative side...