Strange and big problem with my SS2

[eddy52]

Since one week I have a big problem with my old SS2 (Rev2.3). It tunes just a few transporders for example at nilesat satellite i get only 12284 MHZ transporder for all others NO Signal.Am sure that my lnb and cable are ok (have tested them with another receiver..).
I have read somewhere that the coil marked 271 (270UH) have to be remplaced , I replaced it with a torroide one desoldered from a desktop psu, have also reed that the 331 (330 ohms) resistor near the above mentionned coil may the problem so i remplaced it with ahother one, have also replaced one suspected 100UF capacitor with a standard electrolytic one. Still no luck I continue to have just one transporder. My ss2 have worked for several years without problems, So please what else have I to test or to replace or is it the tuner.

Another strange issue : with progdvb the few channels i can get are duplicated 7 times with different frequencies all above 12000MHZ (MTV germany 7 times , comedy central germany 7times..). This device will make me crazy... So please any idea about what is happening.

 

[Llew]

Yes the choke burns out as there is no overvoltage cutout provided on that SS2 version. I had to rewind mine, still working happily.

Seems like you have more problems with the card, maybe the DiseqC switching circuit has gone belly-up.

Llew

 

[eddy52]

Thanks for replying Llew,

I have to say that i'm not using any disecq capability (just one lnb connected directly to the SS2) so even if the DiseqC switching circuit has gone belly-up could this in my configuration be a problem ?

 

[Llew]

Sorry, meant the 22kHz LO switching. The usual problem is that the coil shorts out ( it's there to prevent damping of the 22kHz waveform by the 13/18V DC coming from the DC/DC converter chip). This means you lose the switching, and the LNB stays on low band.

It seems that you are permanently stuck on high band, so no actual switching is taking place. If your application's configuration is set for a Universal LNB, that's unlikely to be your problem, I would guess the SS2 22kHz circuit is at fault. Not sure where to check on that version, only have a power supply schematic for the SS2 2.6 version ( some changes in the PS circuit).

Llew

 

[eddy52]

Yes this makes sens. Could you please indicate the main suspicious components involved in the 22khz circuit for the 2.6 version since the component labels of both versions are probably identical (i mean the component names mentioned on the pcb). Thanks.

 

[Llew]

Refer to the schematic I've attached here, but be aware that the components are not always as per Rev2.3 - F1 is absent in 2.3, which will blow with a short circuit at the LNB port on the 2.6, leaving choke L7 intact.

THe 22KHz is injected on the left side of the choke, but the circuitry is different to that shown in the diagram, although I believe Q6 is present in Rev 2.3.

Without checking my SS2, I'm not sure of the 22KHz path. I think there is another component that generates it rather than coming from the Flexicop. If I get a chance, I'll check it out.

Llew

 

[eddy52]

Thanks a lot. any other advice or help will be appreciated.

 

[ccchdro]

eddy52 y have same problem with my SS2 r2.3 and y fix the problem re-waiting de card flash firmware with one from othre SS2 r2.3, after y do that y have to shut down the computer and start agin an your SS2 work agin. Is not a hardware problem the SS2 r2.3 firmware is blocket.

 

[BombedOne]

This is well known Q13 problem - it generally burns out very very often. So when it damages, no 30V voltage being supplied to tuner varistors, so it's only able to lock on higher transponders. Absolutely nothing to do with 22khz. Just check tuner legs - one of them should have 30V voltage on it (afaik - #7 leg). If not - than Q13 is blown away. When repairing, don't use same type MOSFET. Just install most powerfull one (For example, I've fitted 50A mosfet, about 100 times more powerfull than original one). I've repaired more than 10 SS2 REV 2.3 cards with this problem, and installed powerfull MOSFET there. All work OK now.

Absolutely no need to reflash or so on.

 

[mastercare]

hi bombedone
i have a faulty skystar2 rev 2.3 would q13 gone have the effect on say astra only tuning taquilla chs?
i have found it on board marked ss it seems q14 is marked the same can i swap these around to see if diff fault occurs...i dont have nay mosfets here..
from pins of tuner starting away from F connector i have
1 = 5v
2= 5v
3= 0v same 4 5 6 7
8= 5v
9= 1.2
10=5v
11=1.02 rises to 3.6v when i run up dvb app and i have a fta ch on asta 19.2
12=5v
13=12.8
13=12.8

cheers

 

[mastercare]

changed q13 all fine now card been working 2 weeks now...
thanks for all the tips...