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Discussion Starter #1
I just received my TU-HDS20 back from the Panasonic service center after having two modifications installed. The first mod addressed the issue of excessive fan noise. The mod was quite substantial and consists of a new chassis with large cutouts in the sides, a new top cover with added side vents and a resisitor whose function I presume is to slow the fan speed slightly. The net result is much less perceived noise from the unit. I say perceived noise because the total sound pressure level from the fan is the same (dBA) but the frequency of the air flow noise is now much lower (the whine is gone) making it seem much quieter. The modified chassis changes the air pressure drop resulting in much lower flow noise. Overall this mod is very effective. I should note that the fan itself is a very exspensive, high quality ball bearing unit. In fact, its noise rating (13dBA) is as quite as any fan in its class.


The second mod addressed the issue of signal drop-out for HD OTA and HD satellite. At first I was not sure what had been done then after close examination I realized that the HD tuner module that contains the Broadcomm RF front end and 8VSB demodulator had been changed. I don't know how effective this is since I rarely had dropouts before but I have not seen any since the mod was installed. The unit seems to re-tune HD stations a bit faster now as well. Overall I must say Panasonic has responded well to user complaints and has made substantial improvements to this unit. These mods combined with the upgraded firmware have addresses most of my issues. I should also note that the mod was done in 4 days which I consider quite reasonable. Since I work near the service center It was a simple drop-off / pickup and quite painless. I reccomend that any owner consider these mods
 

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Thanks doug! This was precisely the news I was waiting for. A couple of follow-up questions. How long have you had your unit before sending it in for the mods and did it cost anything? I know I'll have to pay shipping charges but I was told by Panasonic that at least the fan mod was done free of charge for units purchased less than one year.
 

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Discussion Starter #3
I have had my unit since April. It was manufactured in March of 2001. There was no charge for the either of the mods. I believe that Panasonic will pay the return shipping costs.
 

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Does anyone know what manufacture date these "upgrades" were applied to new units?
 

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Discussion Starter #5
It is my understanding that the mods, at the service center level, just became available within the last several weeks. As such I would supsect that production from August 2001 forward will include these. Regardless, Panasonic will update free of charge ANY TU-HDS20 that does not have the mods.
 

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Discussion Starter #6
The modified chassis dimesions are identical. The only external differences are the new side ventilation slots. This should make it quite easy to determine the if the fan mod has been installed.
 

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Thanks Doug,


Since they don't sell these units in Canada I would hate to go through the hassle of getting it serviced.That's why I want to make sure that the unit I buy has already been upgraded.


Shawn
 

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Quote:
Originally posted by GScott:
Does anyone know what manufacture date these "upgrades" were applied to new units?
I would also like to know.I'm very interested in this unit.


Thanks,

Shawn
 

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Does the firmware upgrade allow you to select black or gray bars?
 

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What steps do I need to take prior to sending my TU-HDS20 in to Panasonic? Do I need to call them and get a case number or anything like that? What shipping address should we use? What phone number should we call?


Any input will be most appreciated.
 

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Discussion Starter #12
I did not get a return number or authorization before returning my unit for upgrade. I simply dropped it off with a note saying I wanted the fan noise and drop-out upgrades. The women at the counter was aware of the upgrade program and processed my unit without any question. I took my unit to the service center in Elgin, Il where I believe all units must go. I do not have a shipping address but I'm sure you may obtain that by calling the Panasonic 800 # in the back of the '20 manual.
 

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If anyone buys a new TU-HDS20 with these upgrades already installed, please let the board know. I'm also curious if this upgrade impacts on the "you must have a signal strength of at least 85 to avoid dropouts" garbage. This applied to satellite reception and not OTA.
 

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Discussion Starter #14
Ken, I did some testing with a spectrum analyzer and variable RF attenuator on OTA and DirecTV HD signals. The 85% signal strength stuff is nonsense. I see about 75-85% on the HD bird and could drop the signal down 35 dB (40% signal) before I saw any pixellation or drop-outs. On OTA signals I had 29 dB of dynamic range margin before drop-outs ocurred (30 miles out with a 10 dB average antenna gain). The receiver is quite sensitive, the issue with dropouts I think was / is firmware that controls Broadcomm 5500 receiver ASIC. It needs quite a bit of care and feeding via software to get the most out of it. Also I think that transport stream errors cause many dropouts, its not the receiver fault. It will take few years to get these bugs out on the xmitter end. BTW, you can remove the fan all together and short pins 2-3 of the fan connector, it will work fine. The Fan sucks air out to cool the switching transistors on the power supply. Sans fan it never gets above 80C at the device heatsinks and 60C in the box. I think the fan is overkill, larger heatsink area would work just as well. Overall the unit works VERY well and I love PQ, its a keeper!
 

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Good post Doug. I think what you said makes alot of sense. I had my Panny and was VERY impressed with PQ. I still haven't found a unit that does a better job with upconversion than the Panny. However, it did bug the hell out of me when tech support kept insisting that when my signal strength "dropped" to 80 on the HD bird, my signal stength was inadequate and explained my dropouts.


At this point I'm waiting for the new Zenith tuner. I've been extremely impressed with their first gen tuner incorporated in my Zenith HDTV. Based on this I'm assuming their third gen chip should do a great job. If not, there's always the Panny. BTW, have you been operating the Panny without the fan? I know a few people have done that with the Sony with good results.
 

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I just dropped mine off at the Illinois service center yesterday and noticed that they had TU-DST50s for about $850.00 in the drop off area (kind of a combo service/factory outlet store). Don't know how many they had (at least one) and it was not marked "refurbished" or "open box" like some of the other items (microwaves, vacuums etc). I didn't need one, so have at it...


Regards,

Al H.
 

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Discussion Starter #17
Ken, With the fan noise mod I've left the fan connected as its no longer audable at my listening position. I ran sans fan for some time and monitored the internal temp with a recording DVM. I never saw temperatures anywhere near what I consider excessive. The fan drops the internal temp about 10 C. What drives having a fan is the reliablity engineers desire to statisically improve the failure rate by lower the temp. Cooler is generally better, in this case, in my opinion, its overkill and I'd have no trouble not running the fan.


Regarding the new Zenith, besides the fact that its butt ugly, the only advance I see in the newer chipsets is better multipath performance via longer cancellation EQ loops and more refined DSP code. Since that's not an issue for me, given my suburban location, the driving factors are PQ and features. I find that the format converter in the '20 is quite good and I like the basic feature set. Its beautifully built and I'm sure is a loss leader given whats in the box. My guess is that Zenith will use a Moto, Nextwave, or Broadcomm demodulator as I don't think they do much engineering at that level any more. We have a number of guys working for us that came from Zenith HQ when they shut down the US engineering facility in Glenview Il.
 

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For those interested the address of the Panasonic Service Center is:


Panasonic Factory Service Center

1703 N Randall Road

Elgin, IL 60123


Include a copy of your reciept and a note specifing that you are sending it in to fix the Fan Noise and the Video Dropout issues. The tech I talked to didn't give me an RMA number. He didn't even ask my name or serial number. I suspect that you can just send it to the address above and they'll fix it.


--Rick
 

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They just got mine this morning (tracked it thru FedEx). Hoping I'll get it back in time for "Band of Brothers" on the 9th though it sounds like it might be tight. I sent mine to the 1705 address .. I thought I saw somewhere (maybe the Panny site) that 1703 was for dropoff/pickup only.
 
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