Crypto DVBT 110 SA

[willawake]

its a DVB decoder. Even though they still have only 4 channels and the whole thing did not get off the ground yet, this unit already dead with one bulging capacitor in power supply





1000uf 16v JIALON bulging



rest of the caps are ZHD and SD KSD but mostly small values. This unit really should have the
1000uf 16v (1 piece)
470uf 25v (3 pieces)
to be a good brand.

so thats 4 caps only......

[willawake]

Re: Crypto DVBT 110 SA



dont have any 25v caps so just replaced the 1000uf 16v which had a massive 5.4ohm esr.....with Rubycon MCZ and working again nice. The 470uf ones measured .10 i am not sure of their specs.

I wonder how many of these popular machines (its a greek product) ended up in the trash because of one cap.

[Paul S]

Re: Crypto DVBT 110 SA

Is DVBT terrestrial broadcast (hence, the "T") or satellite? Can you tune in any stations?

Just curious.

[willawake]

Re: Crypto DVBT 110 SA

http://en.wikipedia.org/wiki/DVB-T

uhuh

yeah we have only 4 digtal stations which are basically test channels but occasionally play some good stuff. it didnt get off the ground yet, even though the EC require digital tv switchover, still all the other channels remain analogue. i think it will be 2010 or 2012 before it happens.

i put this antenna its excellent for digital also.

[i4004]

Re: Crypto DVBT 110 SA

to be more precise it's one analog channel(usualy uhf) carrying 4 digital channels, right?
similar situation here(but not test channels, but regilar ones, same we see in analog...but here coverage is nowhere near 100%..you have many places that can't receive digital signal yet)...one wonders how do they think it'll work?
i think many people will just be surprised by losing analog signal one day...

[Gianni]

Re: Crypto DVBT 110 SA

I wonder how many of these popular machines (its a greek product) ended up in the trash because of one cap.

I think a lot of them will finish in the trash also here in Italy.
You can buy it for 60€ up to 150€, I'm talking about DVB-T sets, and if they break out of warranty people prefer to buy a new one because they think it in not worth to repair it.
Most of the time people buy them at big stores and usually they have not great customer support; sometimes you can leave at big stores your stuff, it depends on the appliance and brand, but very often you have to find the closer authorized support center or you have to send your stuff to the manufacturer.
Most people are lazy... so it is faster to buy a new one even if it cost more than a reparation.

There are few small shop's that do such kind of reparations (recap, replace dead semiconductors) and they are very hard to find out.

In august I repaired a 22" Mivar CRT TV-color ( it is an Italian brand) , the owner told me that I was the last resource: he didn't want to bring it to a shop because he didn't know any place personally and he was afraid to finish spending a lot of money to repair an old TV set.
If I was not able to repair it... it finished in the trash for sure.

This is just an example... but there are a lot of people that trash stuff just thinking that buy a new one they get something better: I know some friends that they trash CRT TV just to have a big LCD TV for what???? To see the same shit as before...
But you know... it is trendy to have a flat big screen....

For the time I spend on TV, I will go on with my LG CRT TV color I bought in '99.... I have repaired it 2 times already and I will repair it again if it breaks.

Ciao
Gianni



Gianni

[willawake]

Re: Crypto DVBT 110 SA

to be more precise it's one analog channel(usualy uhf) carrying 4 digital channels, right?

yes thats correct its all on UHF48. i think many people bought TFTs or Plasma recently now they are so cheap so they would be ok (of course if their TFT still alive by 2010-2012.

i still use very old sony trinitron, looks awesome with the pioneer dvd lol

[Paul S]

Re: Crypto DVBT 110 SA

I think that the DVB-T stream is a mp4 compressed video (if I recall my "discussion" with i4004 correctly). I guess that the converter then has a chip to convert it to PAL.

Lots of people here in the USA would love a system like that. Our mpeg-2 system gives us awesome pictures, but the stream is quite large.

[Gianni]

Re: Crypto DVBT 110 SA

old sony trinitron

I have one in my cellar... I'm not able to repair it . I give up last here after I searched for help but it was useless.
It's a pity because in '97 it was expensive, I received this TV from a friend that bought an LCD instead of repairing the Sony.
I worked on it for 2 months, but the problem is still there. Anyway I didn't trash it again... I'm waiting for inspiration to start working on it again.

Ciao
Gianni

[Wizard]

Re: Crypto DVBT 110 SA

Gianni, English please here. What was the problem with this Sony?

Cheers, Wizard

[i4004]

Re: Crypto DVBT 110 SA

I think that the DVB-T stream is a mp4 compressed video (if I recall my "discussion" with i4004 correctly). I guess that the converter then has a chip to convert it to PAL.

Lots of people here in the USA would love a system like that. Our mpeg-2 system gives us awesome pictures, but the stream is quite large.

mpeg4(h264) is today more of an europe's near future than its present. yes, you do have some h264 hd channels on dvb-s(satellite) and yes, you do have some h264 hd channels on dvb-t(terrestrial) but mostly transition to hd still hasn't happen in europe. we'll be skipping mpeg2 hd alltogether, it seems.

what we're getting now is sd (576i...simillar to your 480i ntsc, but better) in mpeg2 form. depending on the broadcaster it usually looks worse than a good analog reception, but good analog reception is not that easy, so for most people such digital mpeg2 signal is improvement.
offcourse, sd is nowhere near hd quality.
europe is probably 5 years behind usa when it comes to hd content availability and coverage.

we had experimental transmission of h264 at 18mbit/s(so same bitrate as your mpeg2) for european football championship this year. consensus is that it looked awesome.
but i doubt 18mbit/s would be used on all channels, although it could be the case: when analog shuts down(aim is the 2011), there will be a lot of free spectra to utilise. they could just replace every analog channel with one hd h264 channel if they wanted.


flat panels? good for hd(esp. plasma), but for sd crt beats them, because crts do no processing to display sd. flat panels do, and a lot of it, and in the end this degrades image.
some of the worst image quality overall was what i saw on panasonic plasma displaying sd. horrible. completely unacceptable ghosting and smearing.

gianni, about that tv: perhaps you could start a new thread here...i'm pretty weak with italian, but on another (local) forum somebody mentioned resoldering stv9379(vertical ic) when it goes on/off(if i understood a bit of what you said there).
there are some other threads about sonys on that forum, so perhaps i could search it for you. it seems not unusual to have sony crt last only 8-9years too.

[zandrax]

Re: Crypto DVBT 110 SA

@ Gianni: if you don't care about pay-tv, there are the so-called zapper or Free-to-air models: no smartcard slots, no MHP support but half the price (30-50 euro) and same image quality. OTOH, zappers are value products and boast only analogue output: if you want an HDMI connector for an LCD or plasma screen, then get the more expensive MHP decoders.

@ Wizard: if I translate correctly, a friend of Gianni asked him to repair a Sony KV-29C1A which displays images for about 10 seconds then the screen blacks for a minute: this problem repeats for about 30 minutes in a 10 s image - 60 s black - 10 s image - 60 s black ... sequence, then the tv works as intended. Sound is unaffected. He found RGB signals disappearing during the black screens. After cleaning the tv from dust, resoldering some supposedly unstable joints and deoxidizing contacts, he hasn't managed to solve the trouble: apparently all caps and ICs are good.

My idea is a chip is dying: problems at cold starts are sign of a degenerative damage. Classical troubleshooting approach is freezing an IC at time with spray ice until you find the culprit.

Zandrax

[arneson]

Re: Crypto DVBT 110 SA

I watch about six channels off the air using the terestrial antenna input and a similare antenna to yours Will.
When the rain fade wacks my satelight at least I get the locals, but the farm is 50 miles away and my antenna is not as high gain as yours.
Picture is perfect though.

[Gianni]

Re: Crypto DVBT 110 SA

@ Wizard i4004
At the moment I have not time/desire to work on Sony, maybe next spring when probably I will have more time.
The problem was the image, sometimes it is on and sometimes it disappear but the audio is always present. I re-soldered everything, I changed most caps... but the problem is still present.

@ zandrax
I know there are zapper... but I really spend so small time watching TV that I can stay without TV, DVB-T, zapper....
I watch sometimes film from DVD so I don't have to see all advertisement.
You have translated perfectly the problem I have with Sony

@ willawake
it's a strange that this happen to me today after your post but here I am.
Today I went to visit my parents and my father asked me to check his DVB-T receiver and you can imagine what I found: I opened it and I found a Suscon 1000uF 6.3V with some rust on the top. All other Suscon look OK, at least they are not bulged or leaking.
The receiver is always in stand by, it doesn't respond to remote control or buttons on front panel.
From the pictures here attached you can see a particular way to avoid X2 cap for EMI noise: immediately after the input bridge there is an electrolytic cap, than you find the input inductance and after it the second electrolytic cap. In this way you have to split in 2 caps the bulk electrolytic cap for the PS but you can save the X2 cap which probably costs more than electrolytic cap.
The brand is Telesystem and the receiver is built in China

I hope it will be enough to replace all caps to make this receiver working again.

Ciao
Gianni

P.S.: damn I'm not able to make clear pics... they are very often blur

[zandrax]

Re: Crypto DVBT 110 SA

I know there are zapper... but I really spend so small time watching TV that I can stay without TV, DVB-T, zapper....
I watch sometimes film from DVD so I don't have to see all advertisement.

I understand, I don't watch tv often too (just news, reportages, documentaries and little more).
Commercial DVDs don't usually have ads, but show draedful and unavoidable warnings about illegal copy (e.g. FBI warning): this is IMHO more unnerving than ads since I payed for it and I can't get rid of

Zandrax

[willawake]

Re: Crypto DVBT 110 SA

i bet it will be ok after recap.
i like to watch dvds really. although not really the new ones. this weekend i watched pirates of the carribean 3 ok but also 2010 and mad max thunderdome.

[Gianni]

Re: Crypto DVBT 110 SA

The rusted capacitor was not the worst, here its measured values:
1000uF 6.3V --> 580uF 0.37 ohm

After replacing it, I tried to turn on the receiver but it was always in the same state, so I started
top remove all caps around PS and I measured their values:

1000uF 16V
--> 543uF 0.65 ohm
--> 730uF 0.18 ohm

470µ 16V
--> 328uF 0.49 ohm
--> 376uF 0.17 ohm
--> 384uF 0.19 ohm

100uF 16V
--> 400nF 548 ohm
--> 6.5uF 82 ohm
--> 12uF 40 ohm
--> 16uF 36 ohm
--> 64.74uF 1.24 ohm

470uF 6.3V --> 376 ohm 0.23 ohm

10uF 25V --> 6.6uF 19.2 ohm

220uF 16V
--> 188uF 0.32 ohm
--> 167uF 0.77 ohm

I replaced them and also the 22uF 400V input caps even if they were still good; unfortunately there are a lot of small caps but I didn't replaced them because I have not such values from good brand in my lab.
Now the receiver works... and I hope the Suscon present in the board will last for long time.
The nice thing I discovered is that it consumes 8.6W when it is on while in stand by the power is ONLY 9.2W .

For this reason I have modified it: I have add a power switch so my father can turn it on only when he need it so saving some energy/money.

Here attached the pics of the shit I removed, the good Rubycon I mounted and the working receiver.


Ciao
Gianni

[i4004]

Re: Crypto DVBT 110 SA

how do you measure 548ohm esr?

[Gianni]

Re: Crypto DVBT 110 SA

Hi i4004

I measured it using a Wayne Kerr LCR Bridge, it is in my lab.
Tomorrow I can tell you the exact model if you are interested.
The cap was probably completely open.

Gianni

P.S.: the input caps 22uF are not Ruby, if I'm not wrong they should be NCC KZG type.

[Gianni]

Re: Crypto DVBT 110 SA

@ i4004: the LCR Bridge is PMA3260A.
It has 2 four channel inputs because you can use it to test transformers: it is possible to measure turns ratio between primary and secondary, leakage inductance, interwindig capacitance....
Frequency range: 20Hz up to 500KHz
It has also a DC bias current, it can supply from 1mA up to 1A.

Ciao
Gianni