DIY gs 8300 receiver repair

Hello, today we will try to fix the Tricolor receiver. Many faced such a problem when the warranty (usually 12 months) expired and the receiver suddenly failed. A new one is expensive, and in most cases the repair will not be difficult and will cost a penny, if you are even a little friends with a soldering iron, the main and most common faults are easy to fix yourself. Let us consider such a repair using the example of another receiver from the Tricolor company GS-8300 N. It must be said that the device is not of the best quality, and the money that Tricolor takes for it, of course, is not worth it. But, nevertheless, the number of subscribers is large and not all of them work for a long time and regularly.

The main and most common malfunction of all receivers is a malfunction in the power supply and voltage conversion circuit. Also, the modulator often fails due to a short circuit in the coaxial cable from the LNB, although the latest models have good protection against short circuits 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 twitching of the power plug from the outlet and turning on the toggle switch does not help us (at least that was the case with the device, an example of which is given in this article) ... The first thing we do is pull out the plug from the network and remove the top cover, we need to get to the electronic filling of the device. And here it is important to remember one thing, namely, about the warranty seal, which of course we will break if we remove the cover. Therefore, once again make sure that the warranty period has 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.

Receiver inside:

The electrolytic or oxide capacitor at the input often dries up and fails, which is also a malfunction, not everyone can find such a breakdown either, you need to have at least an initial level of a radio amateur. Usually, defective capacitors are swollen, yellowish, or have a small brown speck on the board at the base of the legs. Also, the serviceability of a capacitor can be determined by comparing its nominal and measured capacitance.

The receiver uses direct current, which is rectified from the AC mains using a diode bridge. Problems with the diode bridge also happen. It is very simple to check diodes, the main function of a semiconductor diode is to 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, it usually has a radiator to remove heat. I determined the malfunction of the transistor by measuring the voltage at its emitter, it was absent there, the primary winding was not powered, respectively, everything else is de-energized. The transistor cost me 28.5 rubles. Replacing it with a soldering iron, I eliminated the malfunction and the receiver is back in working order. I must say such a breakdown is quite a rare occurrence, usually it all ends with a fuse.

A very common malfunction is a firmware crash. The firmware often crashes, this is usually evidenced by the complete hang of the receiver. In this case, "flashing" will help.I will tell you about one more reason for the malfunction, which may arise due to poor-quality installation. Water in the cable. If the outer insulation of the cable is broken, then water from atmospheric precipitation can get inside, it easily enters the receiver like a hose, sometimes flooding all of its insides. The condition of the cable must be monitored throughout the entire service life of the device.

Written by Administrator on 07 December 2011.

Hello, today we will try to fix the Tricolor TV receiver with our own hands. Many faced such a problem when the warranty (usually 12 months) expired and the receiver suddenly failed. A new one is expensive, and in most cases the repair will not be difficult and will cost a penny, if you are even a little friends 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 GS-8300 N receiver from the Tricolor TV company. I must say that the device is not of the best quality, and of course, Tricolor TV is not worth the money that Tricolor TV takes for it. But, nevertheless, the number of subscribers is large and not all of them work for a long time and regularly.

The main and most common malfunction of all receivers is a malfunction in the power supply and voltage conversion circuit. Also, the modulator often fails due to a short circuit in the coaxial cable from the LNB, although the latest models have good protection against short circuits 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 twitching of the power plug from the outlet and turning on the toggle switch does not help us (at least that was the case with the device, an example of which is given in this article) ... The first thing we do is pull out the plug from the network and remove the top cover, we need to get to the electronic filling of the device. And here it is important to remember one thing, namely, about the warranty seal, which of course we will break if we remove the cover. Therefore, once again make sure that the warranty period has 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.

The electrolytic or oxide capacitor at the input often dries up and fails, which is also a malfunction, not everyone can find such a breakdown either, you need to have at least an initial level of a radio amateur. Usually, defective capacitors have a yellowish appearance, or a small brown speck on the board at the base of the legs. Also, the serviceability of a capacitor can be determined by comparing its nominal and measured capacitance.

The receiver uses direct current, which is rectified from the AC mains using a diode bridge. Problems with the diode bridge also happen. It is very simple to check diodes, the main function of a semiconductor diode is to 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, it usually has a radiator to remove heat. I determined the malfunction of the transistor by measuring the voltage at its emitter, it was absent there, the primary winding was not powered, respectively, everything else is de-energized. The transistor cost me 28.5 rubles. Replacing it with a soldering iron, I eliminated the malfunction and the receiver is back in working order. I must say such a breakdown is quite a rare occurrence, usually it all ends with a fuse.

A very common malfunction is a firmware crash. The firmware often crashes, this is usually evidenced by the complete hang of the receiver.In this case, "flashing" will help. I also want to say about another cause of the malfunction, which may arise due to poor-quality installation. Water in the cable. If the outer insulation of the cable is broken, then water from atmospheric precipitation can get inside and it easily enters the receiver like a hose, sometimes flooding all of 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 the rapid growth and availability of satellite television to the general public, a wide range of satellite equipment has emerged for the general public. These are satellite receivers, conditional access modules, antennas, converters, etc. Whether we like it or not, sooner or later breakdowns occur with them, which cause us to feel the loss of our beloved thing.

You should not despair - for this there are service centers that you can turn to and they will help you to bring your equipment back to life.

Breakdowns of equipment occur for various reasons - voltage drops, failure of various nodes, wear and tear of the equipment itself from its venerable age, you can also note the incompetence of the owners themselves, say, improper replacement of software in satellite and cable receivers.

Power supply failure is perhaps the most common type of digital terminal failure. It arises for various reasons: a poor-quality supply network (see photo), poor-quality radio components were used, especially this is de facto in Chinese technology.

Also, this can include a violation of operation, dust, dirt, as a result of this, the thermal regime is not correct (see photo).

A service center is a structural unit within a company. He is responsible not only for the repair and maintenance of the products sold by our company, but also for the repair (including warranty) of satellite equipment from other companies. Our clients are not only individuals - users, but also equipment dealers who seek to save their customers from the problems associated with the repair and maintenance of receivers. Our flexible corporate customer policy allows us to provide adequate service and meet the interests of all customer groups. This is more than 1000 units of equipment per month. To carry out such large volumes, of course, allows the professionalism of the employees, the equipment of the service center with professional equipment, tools and technical documentation. Therefore, in our service center we carry out high-complexity repairs: for example, replacing processors in BGA cases. Repair takes place in the shortest possible time.

The supply department, in addition to its main function - the purchase of equipment, is also engaged in meeting the needs of the service center, purchasing components necessary for repair. And here it is worth noting that the selection and purchase of components for repair occurs according to the following criterion: the quality of parts comes first, their price comes second, but due to the large volumes of supplies of parts, the price ultimately remains low.
All orders are processed electronically and registered in the database. This makes it easy to track the various stages of the 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 lack of some scarce radio component. Sometimes repairs require a complete replacement of the motherboard, and this repair part is not always available. In this case, we are trying to find some acceptable solution together with the client, taking into account his wishes, combined with our capabilities.

At autopsy, found out of order:
- network capacity C5 - 47µFx400V
- Q1 - CS2N60F
- R8, R11, R13 - each with a nominal value of 3 Om (frame size 1206)
- R9 - 47 Om (1206)
- U1 - it was not possible to determine its type by the marking on the case.

According to the table on identification and selection of analogs https://my.housecope.com/wp-content/uploads/ext/2561/ic_power/, the last part was replaced with SG6848 with minimal interference with the factory circuit.
Dismantling: (circled in red in the photo)
- U1
- R8, R11, R13 - 3 Om (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 1.8 Om x 0.5W resistor (the usual output one, since I did not find the smd of the required rating))
- instead of C3 a 100 kOm resistor (1206)
- instead of R26 a 33 kOm resistor
- instead of R25, we select a resistor in the range of 10-12 kOm, monitoring the voltage 3V3 at the cathode VD8. I settled on the nominal 11 kOm, U = 3.36V (at 10 kOm U = 3.28V, at 12 kOm U = 3.41V)

SSS4N60B (TO-220F package) was installed instead of the burnt-out Q1

On Telesputnik posted a diagram of the power supply unit.

There are inaccuracies:
1. The lower terminal of the primary winding must be connected
to the junction point of the anode D6 and drain Q1
2. Positional designations C2 and C3 are incorrect. C3 must be connected to the 3rd pin
U1, C2 to the 4th pin of U1.
3. Nominal C3 = 68nF
4. In the diagram, there are two capacitors C1
5. Missing C12
6. The primary land is designated in the same way as the secondary one.
7. Missing C8
8.Q2 - MOSFET NTD14N03R
9.Rated C11 = 2200pF
10. Type D8 = SR560
11. Positional designations U3 and U4 are incorrect - they must be reversed.
12. Denomination C5 = 47µF

The receiver turns on, the LNB has 18 volts. There is no video signal, it gets very hot (the finger does not hold) stv 6419 .. because of it there can be no video? there is no other point? (in the sense that more video signal is not to be taken from?) the receiver switches channels ..

GS 8300N receiver there is no video and audio signal through scart to the TV, the channels are switched on the receiver panel.

the video signal from the STi5119ALC chip can be checked with an oscilloscope at the control point opposite the capacitor C117, then it 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 not 12 volts on the board, respectively, there is no power + 12V on the 3rd leg STV6419, a 12 volt Zener diode D3 is faulty near the power connector

There was such an answer: if you use only composite video signal, most likely it can be simply thrown out (replaced with a jumper). And where to put the jumper? if that's the right advice ..

Defective VD3 (VD3 zener diode 12 V) on the motherboard next to the power connector.

Zener diode brand and parameters:

Power supply + 12V for 3rd leg STV6419.
Along the chain: XP5 connector 9th leg -> R81 (300 Om) + Zener diode VD3 (12V) = stabilizer + 12V -> L3 -> 3rd leg STV6419.

Zener diode analog:

VD3 STV6419 similar Zener diode (SMD) did not find. Put a 0.5 watt glass zener diode the size of a diode kd522 ... While the flight is normal.

If replacing the zener diode did not help:

After the thunderstorm, 6419 swelled. After the replacement, the image did not appear, but when checking the strapping, two resistors were cut off, R91, R95... I replaced it, and it worked.

One more problem:

And yet, instead of 13, 18 Volts, 24V was running on the LNB. Replacement required DA1 (LM317T)... And that's it, the flight is normal

The same situation with the GS-8304 receiver:

After 5 years of operation, the GS-8304 suddenly stopped broadcasting, although the indication is working properly.
Zener diode struck at short circuit. Zener diode brand MMZE5242B.

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Fault: the power supply burns out due to overvoltage, so replacing the burned-out elements in the power supply is not possible, it is only possible to replace the entire power supply or alter it.

GS-8300 Power Supply Diagram

Alteration of the power supply:
one). the following elements must be removed from the power supply: Q1, U1, R3, R4, R5, R6, C2, C3, R8, R11, R13, R7, R12, R9, R14.
2). check the following elements for serviceability and, if necessary, replace: check FU1, RV1, RT1, D1, D2, D3, D4, C5, R19, D5, C1, ZD1 (12V), U2 (PC817), resistors R4, R5 solder in parallel to each other to a friend, replace C4 with 47μF, check C14, C9, C15, C18.
3). install the KA5L0380 microcircuit instead of the Q1 transistor as follows, solder the first second and third legs into the board, and leave the fourth one hanging in the air and solder (connect) with a wire to the fourth leg of the optocoupler U2 (PC817) and do all other operations as shown in the diagram.

Diagram of the converted power supply GS-8300

DOWNLOAD DATASHEET: KA5х03ххх.pdf
DOWNLOAD SCHEME GS-8300:
DOWNLOAD INSTRUCTIONS: gs-8300.pdf

The Ferex R&D FP09T001 Rev.2 power supply for receivers is assembled according to the circuit of a pulsed flyback voltage converter shown in Fig. 12. Input mains alternating voltage 190 ... 240 V with a frequency of 50 or 60 Hz through a fuse-link F1, a noise suppression filter C1LF1, which prevents the penetration of noise from the source into the network, a current-limiting resistor RT1 and a diode bridge D1-D4 are fed to a smoothing capacitor C5.

The series resistor RT1 limits the inrush current through the diode bridge D1-D4 while the capacitor C5 is charging. Varistor RV1 protects the source from overvoltage. When the supply voltage exceeds the permissible value, the resistance of the varistor decreases, the current flowing through it increases and the fusible link F1 burns out.

The rectified DC voltage passes through the control unit to the primary winding of the transformer T1. It is switched by a powerful field-effect transistor Q1, which is controlled by the PWI controller U5. The energy stored in the transformer is transferred to the secondary windings and rectified by diodes D5. D7-D9.

To start the power supply when connected to the network, a rectified voltage is used, which comes through the current-limiting resistors R4, R5 to pin 5 of the U5 microcircuit. After starting, a voltage appears on the secondary windings of the transformer T1, and the U5 microcircuit is powered by the voltage rectified by the diode D5, through the current limiting resistor R19.

The stabilization of the output voltages of the power supply is provided by the elements U2 (optocoupler, galvanically decoupling the primary and secondary circuits of the source) and U3 (voltage stabilizer). The rated values ​​of the output voltages are set by the divider R25R26. When they increase during operation, the transistor in the optocoupler U2 opens, and the ShI controller U5 decreases the duration of the pulses that open the transistor Q1.

As a result, the energy transferred to the secondary circuits decreases and, consequently, the output voltages decrease. A +5 V linear voltage regulator is assembled on a powerful field-effect transistor Q2 and a U4 microcircuit. Its nominal output voltage is set by the R35R38 divider. The external view of the power supply is shown in Fig. thirteen.

Satellite TV is evolving with every update and with every new device. Every satellite TV user from time to time encounters problems and errors in the robot of his receivers or other components. This can be due to various factors. For example, older models may fail due to long operating times. Despite their quality and reliability, devices can break down due to unsatisfactory weather conditions, electrical problems or improper use. Let's take a closer look at this.

Among the reasons for the breakdowns of the GS8306, GS8300, DRS-5001 models are the following:

• the receiver does not start;
• the timer flashes on the display of the set-top box at startup;
• on the display of the prefix only a non-blinking timer;
• on the display of the prefix the inscription "boot";
• on the display of the prefix error message ER31;
• an error on the TV display when switching on "Short circuit!" or "Check antenna cable".

In the case of the last error, you can carry out diagnostics yourself to clarify the cause of the malfunction. When the wire was disconnected, the error message disappeared, the problem is with the satellite converter or the antenna cable. Next, you need to check the wire in case of a short circuit. If it is not there, there is an error in the satellite converter. But, if the TV still signals an error, the problem is in the tuner.

These types of breakdowns include other representatives of the series of MPEG-2, MPEG-4 and Full HD set-top boxes. There is no need to prematurely go to the store for another device, because the purchase will definitely cost a lot. It is recommended to contact service center for qualified help, or repair the receiver with your own hands, if you have the necessary skills.

Diagnostics show that often the components of the set-top box fail:

• firmware - this can be detected if you see errors on the display;
• receiver power supply Tricolor - when the receiver does not turn on or the timer is flashing;
• motherboard - only timer is displayed or in case of error ER

However, satellite TV users may encounter picture, sound or signal problems. This also happens due to problems with the receiver. The following are attributed:

• breakdown of the satellite converter;
• the antenna cable is damaged;
• breakdown of the tuner unit;
• weak signal due to obscuring trees;
• unsatisfactory weather conditions.

The reasons also include channel broadcasting frequency change or even a whole package of channels or satellite malfunctions, to which the service center has nothing to do.

First of all, you do not need to start repairing Tricolor receivers yourself if you are 100% not sure what and how you are doing. If the warranty period is valid, it is best to entrust the repair of the Tricolor satellite receiver to a specialist. But, this is possible if there is a warranty card, purchase receipt, client's signature. The repair warranty may be voided if:

• operation of the receiver during power surges;
• damage to the seal or the integrity of the structure;
• mistakes when switching, connecting cables or incorrect programming;
• the receiver was not installed by an installer, and this led to a breakdown during operation;
• the client has violated the terms of use;

All this must be adhered to if the client wishes to repair his receiver in the future.

Repair of the Tricolor TV receiver is as follows:

• replacing the motherboard;
• changing the power supply;
• replacement of the module;
• flashing or reinstalling software.

If the motherboard breaks down, it is most often recommended to buy a new and more modern version of the set-top box, because repairing the motherboard will cost almost at the price of a new receiver.

For example, there are a number of errors typical for each type of device and options for correcting. The peculiarity of the repair of the GS8300 receivers of the Tricolor company depends on the alteration of the power supplies, because the devices are not highly resistant to voltage surges. Overheating was a typical problem for the GS 7300, causing the diode bridge or chip to break. Also, the power supplies for the Tricolor receivers sparked after prolonged operation, so they often had to be changed. The most optimal model, the GS8306, also had typical problems. For example, overheating during prolonged viewing of channels.