Gs 8300m power supply repair circuit. If AV out does not work

Repair of the receiver Tricolor GS8300

Hello. Today I will show the solution to how it turned out to be a common problem. One fine morning, about to watch TV, I was upset by a black screen. Looking at the receiver of the tricolor, he noticed that he seemed to be dead. 🙂

The GS8300N receiver did not respond to power supply (LEDs did not light up). Since the warranty ended long ago, I began to disassemble this device. The picture was unpleasant, the receiver's power supply burned out. This receiver, like the TV, was powered through a voltage regulator from the date of purchase, however, this did not save it.

The power supply capacitor dried up and swelled, several radio elements burned out from overheating.

In order not to breed plagiarism with the text, I will post a video that helped me quickly repair the receiver's power supply. It details the repair process. In addition, the circuit has been slightly redone and works great.

I'll show you the cost of repairs, and then decide for yourself whether it is worth it or not.

  • Microcircuit - 60 rubles
  • Diode - 2 rubles.

If the arms are straight, then it's worth it!

After checking the diodes, I found one broken.

Here is the original diagram of the receiver's power supply.

And here it is, the video! 🙂

If it came in handy, I'm always glad for thanks. If something is not clear I will definitely answer in the comments. I got it right the first time and this redesigned circuit works fine.

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October 2012. During the week, 15 pieces of GS-8300 were brought with dead power supplies, right up to blown up tracks, cracked PCB and burnt SMD resistors.



hover your mouse over the image to enlarge it

How everything happened is clear - the electrolytic or oxide capacitor at the input (C5) dries up, gives ripples, but so far everything works. The transistor of the primary winding of the transformer (Q1) overheats, SMD parts burn out around it, the board tracks crack and the power supply becomes faulty.

Native power supplies ran out long ago, and GS-8300 receivers kept coming and going. Of course, repair was possible by fusing tracks, installing jumpers, soldering parts - in short, it was possible to restore the power supply from the ashes and at the same time it would work properly, although the work did not look very aesthetically pleasing and the client was better off not seeing the result of the master's actions. And, of course, it took a lot of time to repair each unit.


Therefore, I went the other way - I took it and adapted it for the GS-8300 receiver, but I'll just make a reservation that there are several models of power supplies for the DRE-5000, the left one is suitable in the photo below - it is also the most common (the right one in the image does not pass in height )

Pinout of DRE-500 and GS-8300 connectors

No. DRE-5000 GS-8300

30 V

no / delete

22 V

24 V

12 V

body

body

3.3 V

3.3 V

3.3 V

3.3 V

body

body

body

body

body

body

So, what needs to be redone in the block is to remove the 8th and 10th wires from the block and cut them off from the power supply unit itself (we do not throw out one of them, it will be useful to us later), cut off the place of the block for the 10th wire with a knife, total our connector has become 9-pin, the 7th wire is rearranged into slot 8, the cut wire is inserted into slot 7 and soldered to wire 6. Total - we get the GS-8300 connector, although instead of 24V we will have 22V, but this insignificant and tested over the years - does not affect the result.





Further, mechanical adjustment of the power supply unit - we break out the place for the com port socket with pliers, with the same tool we reduce the block length by 3-5 mm. And finally, we transfer the capacitor C1, making room for the power switch




We connect the network wire. We insert the block, placing an insulator - you can plastic from the bottle, fasten it with one screw, the second attachment point is a groove on the body. ready, it remains to close the lid

Thus, about 300 receivers were repaired, in two years one return - C17 was knocked out

Hello, today we will try to fix the Tricolor TV receiver with our own hands. Many have faced such a problem when the warranty (usually it is 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 receiver from the Tricolor TV company GS-8300 N. It must be said that the device is not of the 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 all of them work for a long time and regularly.

Power circuit malfunction:

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 we will of course 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.

Opening the lid, we see printed circuit boards with many components interconnected by wire buses. Below are photos with a description of some 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 supply of the network wire. 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 accustomed to (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 lid 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 rupture. If the fuse has blown, which by the way very often happens, we go to the radio store, buy the same one, change it and that's it. If this is not the case, we check the details 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 the 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 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. Diodes are very simple to check, 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 fixed the malfunction and the receiver is back in working order. I must say such a breakdown is quite a rare occurrence, usually everything ends with a fuse.

A very common malfunction is a firmware crash. The firmware often crashes, this is usually evidenced by a complete hang of the receiver. In this case, "flashing" will help. I also want to say about another cause of a 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 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 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 favorite thing.

You should not despair - for this there are service centers that you can contact and help you 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, for example, 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.

This also includes 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 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 allows, of course, the professionalism of the staff, the equipping 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.

The receiver died after a power surge.

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, the last part was replaced by 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, because 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 \u003d 3.36V (at 10 kOm U \u003d 3.28V, at 12 kOm U \u003d 3.41V)

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

power supply circuit GS-8300

On Telesputnik posted a diagram of the BP.


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 \u003d 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.
7. Missing C8
8.Q2 - MOSFET NTD14N03R
9.Rated C11 \u003d 2200pF
10. Type D8 \u003d SR560
11. Positional designations U3 and U4 are incorrect - they must be reversed.
12. Denomination C5 \u003d 47µF

If AV out does not work

Question:

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 ..

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

Decision:

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 supply + 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 you can simply throw it out (replace it with a jumper). And where to put the jumper? if that's the right advice ..

Defective VD3 (VD3 zener diode at 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 ---\u003e R81 (300 Om) + Zener diode VD3 (12V) \u003d stabilizer + 12V ---\u003e L3 ---\u003e 3rd leg STV6419.

Zener diode analog:

VD3 STV6419 similar Zener diode (SMD) did not find. Put 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 a 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 ...

Repair GS-8300

In this article we will repair the "tricolor" receiver with our own hands. A common problem is that the warranty period has expired and the receiver suddenly breaks down. It is expensive to buy a new receiver, to carry it to a service center means to deprive yourself of watching satellite TV for a long time. But in many cases, the breakdown of the device can be corrected independently, without spending much effort and a lot of money. If you know how to solder, then it is easier to figure out the faults yourself and fix them.

As an example, we will use the GS-8300 N Tricolor TV receiver for television. It should be noted that the quality of the receiver leaves much to be desired, as it costs decently. Nevertheless, many subscribers use this particular receiver, and not all of them work properly.

we will use a receiver for television "Tricolor TV" GS-8300

The main and most common problem with most receivers is a malfunction in the power supply and voltage conversion system. In addition, a short circuit in the coaxial cable from the LNB will often cause damage to the modulator. Only in the latest models they began to use good protection, which, when closed, stops the voltage supply to the converter until this short is removed.

So, there was a problem: the receiver does not turn on and does not show any signs of life at all, and the indicators on the front panel are off. We tried to twist the plug from the socket, turn on / off the toggle switch - it doesn't help.

Then let's understand further. First, be sure to unplug the plug and remove the top cover with a screwdriver. We need to look at the electronic stuffing of the device. It is important to remember here that when removing the cover, we will definitely break the warranty seal.

Therefore, if the warranty period has not yet expired, it is better not to climb yourself, otherwise you will not be able to repair your receiver under warranty later.

And if the guarantee has passed and you have no one to hope for, then go for it - break the seal.

Tricolor TV GS-8300

Removing the cover reveals circuit boards with various components. They are interconnected by wire busbars. The photo shows some devices with a description. We need to find the power board. It has a transformer and an inlet for the power cord, so it's not difficult to find it. The first thing to look out for is the fuse, which is usually installed at the beginning of the circuit. The fuse can take many forms, such as a glass capsule with a conductor or a small plastic box that contains the fuse. In the second case, you must first remove the cover of the box (you can use tweezers or tweezers) to get to the fuse itself. Next, you need to check the fuse with a tester or multimeter for a break. If it burns out, which often happens, then go to the radio store, buy the same fuse and just change it. If everything is fine with the fuse, then we check further along the circuit.

Another element that often breaks down is the transformer itself. Such a fault is detected by measuring the voltage on the secondary winding. It is worth noting that not everyone can do the replacement of the transformer. If you are not sure that you can change it yourself, then it is better to take your receiver to a repairman, and if it does not seem difficult for you, then go for it.

Internal structure of the receiver

Internal structure of the receiver

Internal structure of the receiver

Another malfunction is the failure of the electrolytic or oxide capacitor at the input due to drying out. To detect this breakdown, you need to know at least a little about radio mechanics. A defective capacitor is usually yellowish, and a small brown spot can be observed at the base of its legs on the board. In addition, you can compare the rated and measured capacitance of a capacitor to determine if it is working properly.

The diode bridge in the receiver converts the AC mains current into direct current.

The diode bridge can also break. This is easy to check, since a semiconductor diode has one main function: to pass current in one direction, but not in the other.

In the case we are considering, a breakdown occurred with the transistor of the primary winding of the transformer. It has a heatsink to dissipate heat, so it's pretty easy to find. The malfunction was detected as follows: they measured the voltage at the emitter of the transistor, it was not there, the primary winding was not powered, which means that all other parts are de-energized. The cost of the transistor is about 30 rubles. To replace it we need a soldering iron. We eliminate the malfunction, and - "Hurray! It works! " - the receiver is ok again. Note that the transistor does not break down often, mainly receivers fail due to a fuse.

Let's consider another very common malfunction - firmware crash. This happens quite often. A sign of a firmware rally is a complete hang of the receiver. Then we just need to reflash the receiver.

Poor quality, unprofessional installation can also be the cause of receiver breakdown. If the outer insulation of the cable is broken, rainwater or snow can easily penetrate into the cable and, like a hose, seep into the receiver, filling all its internal contents. Therefore, you need to monitor the cable, whether there are any kinks or insulation faults.

Those who do not understand anything about the internal structure of satellite receivers, or who have no time to deal with this at all, should not despair if the device breaks down. Service centers have not been canceled yet. There you can contact your problem and the specialists will help you solve it.

Receivers fail for various reasons

Receivers fail for various reasons - this is a voltage drop, and wear of the device itself due to intensive use, and the failure of certain elements. This can also include breakdowns due to owners who themselves decided to figure out the problem without having special skills, for example, they incorrectly replaced the firmware in a satellite or cable receiver.

The power supply is, perhaps, the most breakable part of the receiver. The power supply can break due to a poor-quality supply network, due to poor-quality radio components (especially on cheap Chinese equipment).

Dust and dirt can also cause the receiver to fail, creating an incorrect thermal regime.

Dust and dirt in the receiver can also damage the receiver.

The service center repairs and maintains various satellite equipment. Moreover, repairs are carried out by specialists and on professional equipment. Almost any defective part can be replaced with a new one. Repair times will depend on the availability of parts at the service center. If any part is missing, it will be ordered from suppliers, which will take some time. But in large, serious centers, usually, parts are always in stock.

Consider another situation: the receiver failed after a power surge. After opening the cover, the following parts were found to have burned out:

network capacity C5 - 47µFx400V

R8, R11, R13 - 3 Om each (frame size 1206)

R9 - 47 Om (1206)

U1 - type not defined

On the Internet, we found a page with a table on the identification and selection of analogues (for example, http://remont-aud.net/ic_power/), using it we look at what we have and what we don’t have. Replace the last part with the SG6848 to minimize interference with the factory circuit.

We dismantle the defective parts (circled in red in the photo):

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)

Installing new children

instead of U1 - SG6848

instead of R8, R11, R13 - one resistor 1.8 Om x 0.5W

instead of C3 a 100 kOm resistor (1206)

instead of R26, the resistor is 33 kOm

instead of R25, we select a resistor in the range of 10-12 kOm, controlling the voltage 3V3 at the cathode VD8, stop at a nominal value of 11 kOm, U \u003d 3.36V (at 10 kOm U \u003d 3.28V, at 12 kOm U \u003d 3.41V)

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

Installing new parts in the receiver

Power supply circuit GS-8300

GS 8300 is the first receiver in the line of receivers for Tricolor TV, which supports the MPEG-4 compression format and the DVB-S2 broadcast standard. This is the first receiver to accept over 150 channels. We can say that a new era of receivers for receiving Tricolor TV began with him. It's funny, but it began, like many receivers for Tricolor TV, with problems of a different nature. Either the receiver was activated for a long time, then the card did not see ...

But. As a result, the stability of the receiver was improved with new firmware. This material is not about the troubles of the GS 8300 receiver, but about what it consists of. Consider.

We can say that on this receiver the manufacturer got his hand in the production of MPEG-4 DVB-S2 operator receivers. And judging by the number of GS 8300 receivers in the hands of users, this experiment was a success. The GS 8300 receiver is equipped with a removable access card, but the GS 8300M receiver does not have an access card - the chip is wired into the receiver itself.

The receiver is built on a processor STi5119, FLASH memory with a volume of 4 MB, RAM only 16 MB - a ridiculous amount in comparison with the GS 9303 or GS U510. But the receiver also has a different class, because the 8XXX series does not support HD channels.

So. Below is a photo of the motherboard of the GS 8300 receiver. Both a general plan and close-ups of individual nodes. Maybe someone will find such photos useful.

GS 8300 - general view of the board


And now different nodes close up






And in the photo below, the capacitor of the power supply. The power supply unit fa photo is no longer native, but after replacement. And the capacitor used in it is of a higher quality than in the original PSU. Although the ratings of the capacitor itself are the same.


And here's another element. You can unsubscribe in the comments about its appointment. I myself did not delve into this question.


That’s how I got a photo review of the stuffing of the receiver for the Tricolor TV - GS 8300 today.