Electrical circuit of the receiver gs 8306.
Since April 2012, the NSK company, which is the provider of the TRICOLOR TV CENTER and TRICOLOR TV SIBERIA program package, began the transition to TV broadcasting in HD quality, new service called TRICOLOR FULL HD. For technical support of this service, GENERAL SATELLITE first presented consumers with two satellite receivers high class HD 9303 and HD9305, and then the budget models DRS 8305, GS 8305 and GS 8306.
The article presents full description budget models, the technique for updating them software(software), as well as diagnostics and elimination of typical faults.
Main Features
At the end of 2012, the Serbian company RT-RK designs basic model DRS 8305 on request Chinese company DOWNRIDGE SELECT LIMITED for TRICOLOR TV subscribers in all regions. At the same time, by order of the Russian company GENERAL SATELLITE, DOWNRIDGE SELECT LIMITED is organizing the production of these receivers under the GS 8305 brand and the GS 8306 receiver, which is minimally different from the base model. The GS 8306 receivers went on sale in December 2012, and the GS 8305 and DRS 8305 the following year .
Rice. 1. Appearance receiver GS 8306
The receivers are assembled using a single-processor design. Basic technical specifications receivers are shown in the table.
Main technical characteristics DRS receivers 8305, GS 8305 and GS 8306
| Characteristic | Meaning |
| Acceptable digital TV systems | DVB-S ETSI EN 300 421; DVB-S2 EN 302 307 |
| Cryptocoding system | DRE-CRYPT 3 (ADEC) |
| Input frequency range | 9502150 MHz (level 6525 dBm) |
| Video output signals | Analog SD quality; Digital HD quality |
| Reception modes | MCPC and SCPC (multiple and single program on one carrier) |
| Settings memory | 1000 channels |
| Service information | Teletext, subtitles, receiver control data |
| Control | On Screen Display (OSD) Menu and EPG ISO8859-5 |
| Output connectors | HDMI ( digital signals) and RCA (analog signals) |
| Software update | С via USB Flash memory; OTA (Over To Air) via satellite |
| Nutrition | AC/DC network adapter 200240 V/12 V, 2 A |
| Power consumption in operating/standby modes | 25/7 W |
| Dimensions | 25044180 mm |
The block diagram of the DRS 8305, GS 8305 and GS 8306 receivers is shown in Fig. 2. The signal from the external step-down converter through the F-connector (IEC 169-24) is supplied to the input NIM module SP2230MVb from SERIT.
The module consists of an input amplifier, a divider, an IC RF converter-channel selector type M88TS2022 and a DVB-S/DVB-S2 demodulator. The input amplifier compensates for the signal attenuation in the reduction cable from the converter, and amplified signal after the divider it goes to the RF converter and the F-bypass connector (LOOP) to connect the second receiver to one converter.
Rice. 2. Block diagram of receivers DRS8305, GS8305 and GS 8306
The receivers are tuned to the carrier frequency and the input signal is converted to zero frequency with the selection of I- and Q-components performed by an RF converter-selector. From its output, the I and Q signals are fed to the input of the DVB-S/DVB-S2 de-modulator, which provides standard DVB-S demodulation of received QPSK signals with bit rates of 245 Mbit/s, deinterleaving and decoding of Reed codes -Solomon with error correction.
When receiving DVB-S2 standard programs, standard demodulation of received QPSK, 8-PSK, 16-PSK or 32-PSK signals is provided with flow rates of at least 30 Mbit/s (when transmitting TRICOLOR TV programs in the DVB-S2 standard, only 8-PSK is used -modulation). The demodulator also decodes BCH codes, corrects errors and deframes the signal.
In both receiving systems, after error correction, the output Transport Stream (TS) is derandomized and normalized according to the norms of the corresponding standard.
From the demodulator, the TS stream is supplied to the output of the module. The polarization of the received signal and the Ku-band subbands are switched by injecting control voltages into the cable by reducing standard scheme(see, for example,).
From the NIM module, the TS stream in MPEG-4 or MPEG-2 format is supplied to the internal router/router as part of the NP6+ decoder. It is based on a 32-bit ARM1176 core with Harvard architecture, which controls the functioning of the receiver as a whole. Packets of unencoded FTA programs are transmitted directly to the TS-de-mul-ti-plexor, and those encoded in the DRE-CRYPT scrambling system are transmitted to the integrated cryptoprocessor.
The scrambled signal is processed by the DES-desk-rembler as part of the cryptoprocessor. The receivers have a card reader slot for installing smart cards. Through this interface, the card connects directly to the DRE-CRYPT descrambler as part of the cryptoprocessor.
From the output of the cryptoprocessor, the TS stream goes to the NP6+ IC router, which transmits packets to the TS-de-multi-plexor. The required TV or RF channel or service information data signals are extracted from the stream in accordance with the MPEG-2 ISO/IEC 13818-1 standard specification.
Selected compressed video and audio packets of the program required for viewing are decoded in an MPEG-2/4 decoder based on the second processor core.
From the output of the decoder, a digital uncompressed video signal in 4:3 or 16:9 formats (720x576p, 1920x1080i) is supplied in parallel view to the ADV7520B HDMI/DVI transmitter IC, and in serial form to the digital HDMI output. The digital video signal, converted by the DENC encoder of the NP6+ IC into analog form, is supplied to buffer output amplifiers. The digital compressed audio signal is decoded by the third core as part of the NP6+ decoder IC and is supplied to RCA connectors through the UDA1334BTS dual audio DAC. Digital uncompressed audio is also sent to the HDMI output.
The software modification of the control processor and cryptoprocessor in the NP6+ IC can be performed using USB Flash memory. The media is connected via an interface on the USB3320 IC directly to the NP6+ IC.
Hello, today we will try to fix the Tricolor TV receiver with our own hands. Many people have encountered this problem when the warranty (usually 12 months) has expired and the receiver suddenly breaks down. A new one is expensive, and in most cases, repairs will not be difficult and will cost pennies, if you are even a little familiar with a soldering iron, the main and most common faults are easy to fix yourself. Let's consider such a repair using the example of another receiver from the Tricolor TV company GS-8300 N. I must say, the device is not the most best quality, and the money that Tricolor TV takes for it, of course, is not worth it. But, nevertheless, the number of subscribers is large and not everyone has everything working for a long time and properly.
Power supply fault:
The main and most common malfunction of all receivers is a malfunction in the power supply circuit and voltage conversion. Also, the modulator often fails due to short circuit V coaxial cable from LNB though latest models have good protection from a short circuit in the cable, when triggered, the voltage supply to the converter simply stops until the short circuit is eliminated.
And so, our receiver does not show any signs of life, the indicators on the front panel display do not light up, and no amount of juggling the power plug from the socket and turning the toggle switch on or off helps us (according to at least, this was the case with the device, an example of which is given in this article). The first thing we do is unplug the plug from the network and remove top cover, we need to get to the electronic filling of the device. And here it is important to remember one thing, namely the warranty seal, which we will certainly break if we remove the cover. Therefore, make sure once again that warranty period It’s definitely expired, and under warranty no one will repair it for you. If the warranty is still valid, I advise you to take the receiver to a service center and entrust this matter to a specialist.
Opening the lid we see printed circuit boards with many components interconnected by wire buses. Below are photos describing some of the devices on the board. First of all, we are interested in the power board; it is not difficult to distinguish it by the transformer installed on it and the power supply cable. And the first thing we pay attention to is the fuse. It is usually installed at the beginning of the chain. The fuse will not necessarily have the shape you are familiar with (a glass capsule with a thin conductor inside), for example, in my case the fuse is enclosed in a small plastic box, and in order to get directly to the fuse itself, the cover of this box must be removed. This is done very simply, for example, with tweezers. Having reached the fuse, we check it with a tester or multimeter for a break. If the fuse burns out, which by the way happens very often, we go to a radio store, buy the same one, change it and that’s it. If this is not the case, we check the parts further along the chain. Often the transformer itself fails; we can detect such a malfunction by measuring the voltage on the secondary winding. I must say that not everyone can replace the transformer, if so, then it is better to take the receiver to a workshop, but if you are confident in your abilities, then go ahead, for example, it will not be difficult for me.
Receiver inside:
The electrolytic or oxide capacitor located at the input often dries out and fails, which is also a malfunction; not everyone can find such a breakdown either, you need to have at least entry level radio amateur. Typically, faulty capacitors will have a yellowish appearance, or a small brown spot on the board at the base of the legs. Also, the health of a capacitor can be determined by comparing its nominal and measured capacity.
The receiver uses direct current, which is rectified from the AC network using a diode bridge. Problems with diode bridge happen too. Diodes are very easy to check, the main function is semiconductor diode, pass current in one direction and not in the other. In my case, the transistor of the primary winding of the transformer turned out to be faulty; it is not difficult to find; it usually has a radiator for heat removal. I determined the malfunction of the transistor by measuring the voltage at its emitter, it was absent there, the primary winding was not powered, and therefore everything else was de-energized. The transistor cost me 28.5 rubles. Replacing it with a soldering iron, I fixed the fault and the receiver is in working order again. I must say that such a breakdown is quite a rare occurrence; usually everything ends on the fuse.
A very common problem is a firmware crash. The firmware often crashes, which is usually evidenced by the receiver completely freezing. In this case, “reflashing” will help. I would also like to say about another cause of malfunction, which may arise due to poor-quality installation. Water in the cable. If the external insulation of the cable is broken, then water from precipitation can get inside and easily enter the receiver like a hose, sometimes flooding all its insides. The condition of the cable must be monitored throughout the entire service life of the device.
Electronic devices surround us everywhere: on the street, at work, at home. With rapid growth and availability satellite television appeared for the masses wide choice satellite equipment for the population. This satellite receivers, modules conditional access, antennas, converters, etc. Whether we like it or not, sooner or later breakdowns happen to them, which make us feel like we have lost our favorite thing.
There is no need to despair - for this purpose there are service centers that you can contact and they will help you bring your equipment back to life.
Equipment breakdowns occur due to various reasons- voltage drops, failure of various components, wear and tear of the equipment itself from its venerable age, you can also note the incompetence of the owners themselves, for example, incorrect replacement of software in satellite and cable receivers.
A power supply failure is perhaps the most common type of malfunction of digital terminals. It occurs for various reasons: poor-quality power supply (see photo), low-quality radio components are used, especially this is de facto in Chinese technology.
This also includes improper operation, dust, dirt, and as a result, incorrect thermal conditions (see photo).
The service center is a structural unit within the company. He is responsible not only for the repair and maintenance of products sold by our company, but also for the repair (including warranty) of satellite equipment from other companies. Our clients are not only individual users, but also equipment dealers who strive to relieve their customers from the problems associated with the repair and maintenance of receivers. A flexible policy towards corporate customers allows us to provide adequate service and satisfy the interests of all customer groups. This is more than 1000 units of equipment per month. It is, of course, possible to carry out such large volumes due to the professionalism of the employees and the equipment service center professional equipment, tools and technical documentation. Therefore, our service center carries out highly complex repairs: for example, replacing processors in BGA cases. Repairs take place in the shortest possible time.
The supply department, in addition to its main function - purchasing equipment, also deals with the needs of the service center, purchasing components necessary for repairs. And here it is worth noting that the selection and purchase of components for repairs occurs according to the following criterion: the quality of the parts comes first, their price comes second, but at the expense large volumes supply of parts, the price ultimately remains low.
All orders are processed in electronic form and is registered in the database. This makes it easy to track various stages repair process. A guarantee is provided for the work performed.
Of course, unforeseen moments happen - for some reason the repair is delayed. This usually happens due to the absence of some scarce radio component. Sometimes repairs require complete replacement motherboard, and this repair part is not always available. In this case, we try to find some acceptable solution together with the client, taking into account his wishes, combined with our capabilities.
The receiver died after a power surge.
Upon opening, the following were found to be out of order:
- network capacity C5 - 47µFx400V
- Q1 - CS2N60F
- R8, R11, R13 - each with a nominal value of 3 Ohm (size 1206)
- R9 - 47 Ohm (1206)
- U1 - it was not possible to determine its type based on the markings on the case.
According to the table for identification and selection of analogues, the last part was replaced with SG6848 with minimal intervention in the factory circuit.
Dismantling: (circled in red in the photo)
- U1
- R8, R11, R13 - 3 Ohm (1206)
- R3, R6 (one of them is possible) - 1 MOm (1206)
- C3 - 68nF
- R25 - 3.6 kOm (0805)
- R26 - 10 kOm (0805)
Install:
- instead of U1 - SG6848
- instead of R8, R11, R13 - one resistor 1.8 Om x 0.5W (regular output, because I didn’t have the SMD of the required value))
- instead of C3 there is a 100 kOm resistor (1206)
- instead of R26 there is a 33 kOm resistor
- instead of R25, we select a resistor in the range of 10-12 kOm, controlling the 3V3 voltage at the VD8 cathode. I settled on a nominal value of 11 kOm, U=3.36V (at 10 kOm U=3.28V, at 12 kOm U=3.41V)
Instead of the burned out Q1, an SSS4N60B (TO-220F body) was installed
GS-8300 power supply diagram
Telesputnik posted a power supply diagram. 
There are inaccuracies:
1. The bottom terminal of the primary winding must be connected
to the connection point between anode D6 and drain Q1
2. The position designation of C2 and C3 is incorrect. C3 should be connected to the 3rd pin
U1, C2 to 4th pin of U1.
3. Rating C3=68nF
4. There are two capacitors C1 in the diagram
5. No C12
6. Primary land is designated in the same way as secondary.
7. Missing C8
8. Q2 - MOSFET NTD14N03R
9. Rating C11=2200pF
10. Type D8=SR560
11. The position designation of U3 and U4 is incorrect - they need to be swapped.
12. Rating C5=47µF
If the AV output does not work
Question:
The receiver turns on, there is 18 volts on the LNB. There is no video signal, it gets very hot (can’t hold your finger) stv 6419..could there be no video because of it? Is there no other point? (I mean, there’s nowhere else to get a video signal from?) The receiver switches channels..
Receiver GS 8300N there is no video and audio signal through scart to the TV, channels are switched on the receiver panel.
Solution:
the video signal from the STi5119ALC processor arrives, you can check it with an oscilloscope on control point opposite the capacitor C117 then comes to the resistor R87 and is transmitted to the capacitor C129 and then goes to the STV6419 microcircuit from it there is no output to R91, the culprit is no 12 volts on the board, accordingly there is no + 12V power supply to the 3rd leg of the STV6419, the 12 volt zener diode D3 is faulty near the power connector
There was this answer: if you use only a composite video signal, most likely you can simply throw it away (replace it with a jumper). Where should I put the jumper? if this is the right advice...
VD3 (VD3 12 V zener diode) on the motherboard next to the power connector is faulty.
Zener diode brand and parameters:
Power supply +12V to the 3rd leg STV6419...
Along the chain: connector XP5 9th leg ---> R81 (300 Om) + zener diode VD3 (12V) = stabilizer +12V ---> L3 ---> 3rd leg STV6419.
Zener diode analogue:
I couldn’t find a similar VD3 STV6419 zener diode (SMD). Delivered 0.5 watt glass zener diode the size of a diode kd522 . So far the flight is normal.
If replacing the zener diode does not help:
After the thunderstorm, 6419 swelled. After the replacement, the image did not appear, but when checking the wiring, two resistors turned out to be broken, R91, R95. Replaced it and everything worked.
Another problem:
And yet, instead of 13, 18 Volts, the LNB received 24V. Needed replacement DA1 (LM317T). And that's it, the flight is normal
The same situation for the GS-8304 receiver:
After 5 years of operation, the GS-8304 suddenly stopped broadcasting, although the display was working properly.
The zener diode has broken through to short circuit... Zener diode brand MMZE5242B...
Click! gs 8306 after update, repair!
Gs 8306 stopped turning on completely after the update. Maybe both LEDs on the display are lit and then the receiver hangs. All this suggests that the receiver has lost boot sectors, simply broke. If, as a result of the diagnostics, it is confirmed that the problem is in flash memory, then we carry out a procedure to restore our receiver to working condition.
We disassemble the receiver and prepare our main board for repair.
gs 8306 stopped turning on after the update.
If necessary, we clean the main board from dust and other contaminants.
We are repairing Gs 8306.
We take flux and apply it to the contacts of the microcircuit. All contacts must be covered so that it would be easier to remove our microcircuit from main board.
Gs 8306 remove the flash drive.
We turn on the soldering station, take a hairdryer and begin to warm up the element that we need to remove. In this repair we are interested in W25Q128BV.
W25Q128BV programming
After we have removed the chip from the main board, we begin programming. To do this, we need a programmer and a corresponding socket - adapter.
Repair of W25Q128BV on 8306.
We insert it into the programmer and turn on the program. Let's see if the device recognizes our flash drive.
programming W25Q128BV on chipprog 48
If everything is in order and the contact is good, then you can upload a new dump into the chip’s memory. ChipProg-48 during operation will show what state it is in; if there is an error, the red indicator will light up.
ChipProg-48 programming 8306
After everything has been flashed, we mount the microcircuit on the board. First we apply flux.
We do 8306 after an unsuccessful update.
When everything is soldered, wait until everything cools down. Take the front panel and connect the power. Our receiver is starting to work! We check our receiver in all modes.
If you still have questions, you can watch our video, in which we showed everything clearly! The main thing is to remember, if you are not confident in your abilities, then take the broken receiver to a service center!