Zenith (LG) DTT900 CECB - Page 80

Looks like Zenith designed these thing to fail....
My Feb 2008 DTT900 box is starting to go into standby intermittently. (power-off disabled) Also notice some streaking in the picture....like an analog antenna would give with a bad connection, sound is OK until it drops into standby of course.

Wonder which part of the DTT900 is failing the tuner IC that runs hot or the LG processor with flaky solder?

I reseated the power connector, from the PS board to the receiver board, @ the receiver end. My problem went away....8 hrs and still running.

Might not be the only thing malfunctioning. While I was replacing the cover, still powered on (don't recommend this) the audio dropped out several times. I used a screwdriver handle to tap around inside the box and whenever I taped on the tuner tin-can the audio would drop out. Must be something a little loose inside. If I get the nerve to pop the cover I'll report my findings.

I've been trying to decide on a CECB for a few months now. I didn't have an urgent need for one; it would serve as a backup should my Samsung DTBH260F die. Of course I would lose HD but at least I could leverage SD for my ASTC tunerless television.

In the beginning it seemed Zenith (or equivalent) LG-based CECBs were the most popular and highly regarded units. But then they became largely unavailable, or over-priced ($59 at Best Buy). Reviews of other CECBs seem to indicate that a majority are cheaply made, and often prone to overheat. Although net out of pocket for a CECB doesn't amount to much (thanks to government coupon), I didn't want to buy some flimsy device that would die an early death.

I was very close to ordering the Channel Master but I thought it was a bit pricey for my needs. I've seen many reviews bestowing accolades on its picture quality and sensitive tuner; it sounds like this unit is probably the leader of the pack. If I needed a CECB for my primary television I would have went with the Channel Master.

I also thought of the Tivax. Nice reviews, and the Smart antenna port is interesting. The price through amazon.com is also good. But today I went to Kmart. There were two Zenith units on the shelf. Price: $49.99. The manufacture date: March 2009. So with this newly manufactured unit staring me in the face I couldn't resist the purchase (I had the gov't coupon with me).

My impressions:

Firstly, this unit is very solidly constructed. It feels even more substantial than my Samsung DTBH260F which cost $150. I think if you were to whack someone over the head with the Zenith you would crack their skull rather than dent the unit. At least from its physical attributes one senses Zenith didn't rush this to market as a "throw away" item.

Secondly, its user interface, remote and displays are all very logical. Even your grandmother can work this thing.

Picture quality: compared to what my DVDR (with ATSC tuner) produces, the Zenith is comparable. At first glance I thought the picture might be a little less crisp (softer). But on a large screen viewed from several feet away the picture looks fine, probably as good as you could expect using composite video.

Tuner sensitivity: disappointing perhaps. My Samsung STB and DVDR have 5th generation tuners in them. The Zenith presumably has a tuner based on the most current technology. But I could not bring in any more stations with the Zenith; I was hoping for a little better. To be fair, it might be that my hopes were a bit unrealistic.


All the other things like CC and EPG are not of importance to me.

So at any rate, I am very pleased with the Zenith overall. It's seems to be the Toyota of CECBs (..maybe the Channel Master is the BMW?). I can suggest that folks check out Kmart to see if they are indeed stockpiling newly manufactured Zenith units.


_Lazza

Hello, I'm trying to program the Zenith DTT900 remote to turn on our SHARP TV. We had it programmed but for some reason its no responding to the controls. I misplaced our Users Guide and cant find anything online. Can someone please give step by step instructions how to progam this with the codes if necessay.

1. While pressing and holding down the TV POWER button, press the CH up or CH down repeatedly until your TV is turned on or off. Each press of CH up or CH down button sends a manufacturer code (1-45) to your TV one after the other.

2. Release TV POWER button when your TV is turned on or off.

Thanks for the quick response DD, :thumbup:

Were there any DTT900's with a Sanyo tuner that did not have the sibilance problem? Many users have reported that the Sanyo tuner has slightly more sensitivity than the LG tuner.

If I recall correctly I believe the Sanyo tuners were last reported in DTT900 production of February or March 2008. There was some mention that the sibilance was corrected during late March 2008 production but that may not have been verified.

DTT900 models produced in April 2008 no longer had sibilance issues but there remained a disparity between stereo and mono gain levels.

I recently gave away a LG-tunered DTT900 of April 2008 manufacture. The main board of that DTT900 is pictured below. The side by side photo shows DTT900 and DTT901 models, both of April 2008 manufacture.

The April 2008 DTT900 models were the last produced prior to the changeover to DTT901 production beginning in April 2008.

All DTT901 models have a LG tuner, corrected audio with no gain disparity between mono and stereo. (I have a DTT901 of April 2008 production but it is not currently in use.)

I did a side by side comparison when the 901's first came out and IMO the PQ and even reception were basically the same. Very good reception on both and good PQ on both.

Topic title changed.

I went on vacation for eight days, and when I came back, one of my two Insignia/Zenith DTT901's lost it's memory. All the unwanted channels I had blocked were unblocked, and the zoom setting was back to "normal" instead of "zoom" for my 3:2 TV. I had to go back in and deselect each unwanted channel again, and reset the zoom mode for each channel. Nobody had access to the tuner to screw it up while I was away. Anybody had this happen, or know why?

We have two BestBuy Insignia converter boxes (Zenith private label). One we leave one all the time the other is on a computer that gets turned on/off each day. Have not had any problem with them forgetting settings. Sounds like nonvolitile memory in the box got corrupted.

The only weird thing we've seen is with the remote. It can be programmed to turn TV on/off. It forgets if you need to change the battery with is to be expected but it seems to forget at other times.

/tom

Only problem I've had with one is the blue light doesn't come on any more. Which is just fine - one less distraction.

I have 2 900's .... one feeding a ReplayTV the whole system on an UPS. The other in the bedroom TV. (no UPS) Occasionally the one in the bedroom will be in the off-mode and I have to turn it on again. I can't say for sure that a power "bump" or "brown-out" causes this....but I can say after a power failure it will.

I can confirm this to be a subtle annoyance with these.
I live in an area that does something with "The Grid" early every mourning that causes a very short brown-out glitch.

I had to add larger electrolytic capacitors to the internal supply to stop that annoyance.

A legitimate power outage did not cause it, only the grid switch (Or whatever they did every mourning).

They saved a penny on a larger capacitor,
and released an unstable power supply for logic board usage as result.

WeThePeople which capacitor did you replace in the power supply?

FWIW, here is a photo of an April 2008 DTT900 model's power board:

Sadly, both the DTT-900 and the DTT-901 would not work in my area,
even though the CM-7000 would.
hence I no longer own them (Traded one Zenith for my second CM-7000).

But if you open DigiDo's pic from the post between your question and this answer.
In the upper left part of that pic you'll see the four diodes that make up a full wave rectifier bridge.

I pulled a pair of leads off of the positive and negative terminals of the electrolytic capacitor
those diodes feed to a large computer capacitor mounted off-board.
Most likely that largest radial mount cap. to their right.

I know...overkill...

That, if I recall correctly, wasn't the service voltage of the unit.
It was a rectified version of the line current that fed a charge-pump style PWM regulator.

So note the voltage rating on that cap. to be sure...



Hope that helps.

Damn, the same DTT901 just did it again. It didn't respond to the initial power-on command. On second attempt when it turned on, it didn't lose it's channel memory, but all the zoom settings were once again panned out, forcing me to zoom every single channel again.

I think you can reset them all at once by selecting your preference in the menu. Then you'd just need to change the aspect ratio on any channels you want a different way.

Do you know which area of the menu? I don't recall ever seeing such a setting. Thanks.

Menu....Option....Aspect Ratio -- and then select the one you want.

If the unit is turned off and unused for a week or more, you need to restore the Zenith's memory.

OK, my Zenith DTT 900/901/Insignia boxes have been hacked/boards swapped so many times for various reasons, I lost track of what was actually in each box. Last night I noticed the guide on one of my units was off by an hour, so I went in to the menu to adjust the time. Found out that the time can't be adjusted, but the daylight savings time feature could be switched to off, which made the clock and guide correct. (It had been on "auto" which should have been correct, but...???) I also noticed the picture could be seen through the menmu screen, which was semi-transparent.

Then I went into the other room to adjust the clock on my other Zenith. I found the menu screen solid (could not see the picture through the menu) and there was no daylight savings time adjustment feature. I assume the first box was the newer DTT901, and the one without the DST adjust feature and solid menu screen is the earlier DTT900? Adjusting DST on the first one got the job done, but what about the DTT900? How do you adjust the actual clock on it, or either one, for that matter? Is it set by the incoming signal, with no way to over ride it? If so, why is the clock off by an hour, which makes the guide wrong, too? Thanks.

Change the time zone. Problem solved.

I had a similar problem with my Hitachi VCR, started when the gov't moved DST dates. I think I was able to go back to Auto after all was said and done (until next time!).

Like you said. Change time zone, problem "solved."

Hello.

Does anyone know why Zenith DTT900 (4/2008) converter boxes (have a few) like to forget channels and require rescans? This is in Los Angeles, CA, USA area.

Thank you in advance.

By forget, do you mean that the "virtual" channel number is no longer there, or does the channel no longer show a picture?

Even post digital transition date on June 2009, viewers are encouraged to rescan regularly as the stations will be upgrading their transmitters, changing antenna positions, and even changing back to their "original" channel frequency. The virtual channel number will not change, so a rescan is required.

I have not heard of the NVM losing it "memory". Do you have occasional power outages or surges in your area?

The rule of the day is to resan often... or until the digital dust settles.