Originally Posted by Majorota
Thank you to JoeKustra for referring me to this forum after I posted my Amazon review of the CM 7400 (which was actually purchased at and subsequently returned to Fry's Electronics). I am copying my review below since I am unable to post URLs as a new member:
1 out of 5 stars Unstable, overheats, disappoints,
January 9, 2012
This review is from: Channel Master CM7400 1080p Internet Compatible HDTV DVR (Electronics)
A brief bit of background: I live in SF bay area in the middle of nowhere about 40 miles from nearest HDTV broadcast antenna clusters. After the HDTV broadcast transition (and after my huge roof analog antenna blew down in a storm), I began to experiment in receiving free OTA HD TV as a challenge. After some iterations and research on sites like TVfool, I built a successful and cheap system using the new generation of HD antenna (Clearstream "figure-eight" design, purchased at Costco), combined with a low-noise high-gain mast-mounted preamp (Channel Master Titan2, from Fry's). Even with >100ft of coax after the antenna/preamp combination, I was impressed with the results after carefully aligning the antenna based on the TVfool simulations, receiving 43 HD stations including all major networks using a built in HDTV tuner. All of my neighbors who have TV have satellite, and they can't even get the local SF channels due to programming restrictions.
Long looking for a way to DVR OTA broadcasts, and knowing about the older CM7000, I was happy to see the CM7400 appear. Plus I was very happy with the design and performance of the CM7777 preamp cited above. Because the Amazon price was same as list price and I wanted it before Christmas, I purchased it at local Fry's. There were 4 new boxes when I went, and I bought one. To install I diverted the coax that normally went to the TV and hooked it directly to the CM7400, without any splitters. Installation was fast and channel scan acquired 42 channels (I'm not sure what the 1 missing channel was compared to my TV but it was not anything major). Also I was impressed with the free guide it acquired over the air plus the ability to scan quickly through channels with program info in the top bar on the screen without changing channels (both of these features are missing from my TV). The guide seemed to be populated over at least 24 hours and sometimes longer if the unit stayed on and alive long enough (see below). DVR functions and pause-play on live TV worked great (again when the unit stayed alive). Picture quality was as good as I saw with the raw TV signal with minor exceptions noted below.
So, I give 1 star (vs. zero stars) for the functionality demonstrated above. Unfortunately the unit suffers from serious problems that make it essentially worthless for its stated use. I immediately noticed the high heat levels from the unit but saw other reviews which mentioned this. I also updated to the latest firmware without event. The unit worked great for a day or so. Then, I noticed various instabilities and intermittent problems. The symptoms were always that I would come back after some time, turn on the unit from standby, and then see no reception on all the programmed channels. However, the menus would all be active and the unit was responsive to the remote -- just no video. To fix this I had to do one of 2 things. The easiest was to chose the soft reboot option from the menu (which doesn't clear to factory settings). In some cases, after this reboot, the reception would come back and all would be OK for a while, but it would inevitably fail again. In some cases, a soft reboot would not cure the problem. The only thing that would work was to physically unplug (remove power from) the unit, wait some hours (in some cases overnight) and then on restart it would work again. Obviously this made using it to make reliable timed DVR recordings very sketchy, and also compromised live TV if it needed to be put through a reboot or power-off cycle. My guess is that the overheating problem is coupled to this problem, since sometimes a cool-down period was necessary to restart it. By the way, this is all going on in the middle of winter when environmental temperatures are quite cool, and with the unit having plenty of ventilation from all sides.
Some minor problems I noticed: (1) audio/video out-of-sync issues but they seemed minor and would be intermittent; (2) scrolling animations (common on newscasts) flashed and looked bad on 1080p and other settings, but were best on 1080i; (3) sometimes unresponsive remote; (4) poor code selection for using the remote as universal remote for other equipment.
If this unit had done what it was built for, I would have been happy to keep it and use it with the free OTA guide. However, its performance rendered it useless and a waste of money, so I returned it. When I went back to Fry's, besides mine, there were 3 other boxes on the shelf -- all returned like mine! I can only speculate on the reasons. [An aside: when I returned it I complained it was defective and probably overheats, but the first thing the guy did was print out a price sticker with 5% markdown and stick it on the box so it could be sold again].
Before returning, I looked for more firmware updates in the hope that CM would recognize this as serious problem and fix it quickly, but nothing materialized. I didn't want to waste the time nor money waiting. I am now thinking of turning to HTPC recording and using an network-compatible device like SiliconDust to distribute live signals, and a cheap device like WD TV to watch DVR recordings.
Conclusion: stay away from the CM7400 unless you hear the problems listed above and which other people are having are fixed for good.