Schematic diagram of the power supply gs 8300m. Here is the original power supply circuit of the receiver

SUPRA STV-LC42T400FL (V1N06)
Main HK.-T.SP9202P53

Backlight Driver OB3350CP
Fault:
The backlight turns off in the TV, the sound and image remain, you can see it on the MENU matrix.
Turning off the backlight occurs arbitrarily, the backlight can go out immediately or it can work for half an hour. (according to the client)
In a workshop:
When it arrived for repair, the TV worked for 5 minutes and the backlight turned off.
The solution to the problem did not come immediately.
The first thing I thought was LEDs!
Opened the lid, checked the voltage on the OB3350CP

All voltage is normal when the backlight is working!
When the backlight turns off, the voltage on leg 2 is 0 volts
I decided to open the panel to look at the LEDs ...
Checking the result with the device did not reveal the exact result, it seems that all the LEDs are normal in terms of current, there is no big discrepancy, all the strips glow perfectly.
The only thing that alerted and caught my eye was the place around the diodes, obviously burnt, on some strips it is more noticeable, on others less.
In general, again I installed all the strips on the panel and turned it on without a matrix! UPss... The LEDs blinked and did not light up.
But before I dismantled the panel, the backlight worked for two or three minutes and turned off.
Checked EVERYTHING again! No problems, everything is fine. I decided to check each LED separately for current consumption, I did not find any critical differences.
Well maybe? The TV worked, personally accepted it for repair, and together with the client saw the perfect image.
And now all the LEDs flash and immediately go out, the LED on the TV panel is green, that is, the TV remains in operating mode, you can turn it off with the remote control and turn it on again, then the backlight will turn on again and turn off abruptly, the time is no more than 2 seconds.
I checked again the voltage on the OB3350CP driver, everything is normal, except for the voltage on the 2nd leg, it appears there for a second and immediately disappears.
I decided that the problem is in the chip itself or in the LEDs. There was no such driver available, I decided to change the LEDs for new ones, since I bought it recently.
Further, the replacement of the LEDs did not give a result, everything is the same, the backlight blinks and immediately goes out.
I bought two OB3350CPs, changed all two in turn, but the result is the same.
I decided that the problem was with the lane, but to clear my conscience I decided to check the entire OB3350CP harness again. I cleaned the glue on the backlight connectors, there are also resistors there, washed everything with alcohol and let everything go around under the microscope .... everything is fine!

Only one resistor raised doubts, according to the marking it is 01C (10 kΩ), but when checking for Ohms, it behaves strangely, it increases, then decreases to the norm of 10 kΩ.
Once again I washed everything and soldered this resistor and Finally, it went into MΩ.

All repairs are completed, the TV is assembled and put on the run!
I highlighted the problematic resistor in the photo, there was no circuit during the repair, so it seemed to ring on the third leg of the OB3350CP.

In general, nothing new, who does not work and does not make mistakes)) Just a repair ..., I think in this chassis it will be another type due to the quality of resistors marked 01C.

Repair of the receiver Tricolor GS8300

Hi all. Today I'm going to show you a solution to a common problem. One fine morning, going to watch TV, I was upset by a black screen. Looking at the tricolor receiver, he noticed that he seemed to be dead. 🙂

The GS8300N did not respond to the power supply (the indicators did not light up). Since the warranty ended a long time ago, I began to disassemble this device. The picture was unpleasant, the power supply of the receiver burned out. This receiver, like the TV from the day of purchase, was powered through a voltage stabilizer, however, this did not save him.

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 modified and works perfectly.

I will show 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 punched.

Here is the original power supply circuit of the receiver.

And here it is, the video! 🙂

If it was useful, I'm always happy for thanks. If something is not clear, I will definitely answer in the comments. I got it right the first time and this redone scheme works great.

Be sure to take a look here:

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October 2012 In a week, they brought 15 pieces of GS-8300 with dead power supplies, up to blown up tracks, cracked textolite and burnt SMD resistors.

hover your mouse over the image to enlarge it

How everything happened is understandable - 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, the SMD parts around it burn out, the tracks of the board crack and the power supply becomes faulty.

Native power supplies ended a long time ago, and the GS-8300 receivers were brought up and brought up. Of course, it was possible to repair 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 quite aesthetically pleasing and it was better for the client not to see the result of the master's actions. And, of course, it took a lot of time to repair each block.

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

Pinout of DRE-500 and GS-8300 connectors

No. DRE-5000 GS-8300

	30V	no / delete
	22V	24V
	12V	frame
	frame
	3.3V	3.3V
	3.3V	3.3V
	frame	frame
	frame	frame
	frame	frame

So, what needs to be redone in the block - remove the 8th and 10th wires from the block and cut them off from the power supply itself (we don’t throw one of them away, it will come in handy later), cut off the place of the block under the 10th wire with a knife, total our connector has become 9-pin, we rearrange the 7th wire to socket 8, plug the cut wire into socket 7 and connect it by soldering to wire 6. In total, we get the GS-8300 connector, though instead of 24V we will have 22V, but this insignificant and tested over the years - does not affect the result.

Next, the mechanical adjustment of the power supply - we break out with pliers a place under the com-port socket, with the same tool we reduce the length of the block 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 use plastic from a bottle, fasten it with one screw, the second attachment point is a groove on the body. ready, just close the lid

About 300 receivers were repaired in this way, in two years one return - knocked out C17

Repair GS-8300

In this article, we will repair the "tricolor" receiver with our own hands. Often there is a problem that guarantee period ended, and the receiver suddenly broke down. Buy new receiver expensive, carry it to a service center - that means for a long time deprive yourself of watching satellite TV. But in many cases, the breakdown of the device can be corrected independently, without spending much effort and large Money. If you know how to solder, then it is easier to figure out the malfunctions yourself and fix them.

As an example, we will use the GS-8300 N Tricolor TV receiver. It is worth noting that the quality of the receiver leaves much to be desired, since it costs decently. However, many subscribers use this particular receiver, and not all of them work properly.

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

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

So, a problem arose: the receiver does not turn on and does not show any signs of life at all, and the indicators on the front panel do not light up. We tried to distort the plug from the outlet, turn on / off the toggle switch - it does not help.

Then we understand further. First you need to unplug the plug from the socket and remove top cover with a screwdriver. We need to look at the electronics 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 go in 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 rely on, then go ahead - break the seal.

"Tricolor TV" GS-8300

Remove the cover and you will see printed circuit boards with various components. They are interconnected by wires. The photo shows some devices with a description. We need to find the power board. It has a transformer and a supply for the power cord, so it is not difficult to find it. The first thing you should pay attention to 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 in which the fuse is placed. 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's blown, which often happens, then go to a radio store, buy the same fuse and just change it. If everything is fine with the fuse, then we check further down the chain.

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

Receiver internals

Receiver internals

Receiver internals

Another malfunction is the failure of the electrolytic or oxide capacitor at the input due to drying out. To detect this breakdown, you need at least a little understanding of radio mechanics. A faulty capacitor is usually yellowish in color, and a small brown spot may be observed on the board at the base of its legs. In addition, you can compare the nominal and measured capacitance of the capacitor to determine its health.

The diode bridge in the receiver converts the alternating mains current into a direct one.

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 fault was detected as follows: they measured the voltage at the emitter of the transistor, it was not there, primary winding 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 fix the problem, and - “Hurrah! Earned! - Receiver is back to normal. Note that the transistor does not break often, mostly the receivers fail due to the fuse.

Consider another very common malfunction - firmware rally. This happens quite often. A sign of a firmware rally is the complete freezing of the receiver. Then we just need to reflash the receiver.

The reason for the failure of the receiver can also be poor-quality, unprofessional installation. If the outer insulation of the cable is broken, then rainwater or snow can easily penetrate the cable and, like a hose, seep into the receiver, flooding all its internal contents. Therefore, you need to monitor the cable, if there are any kinks or insulation violations.

For those who do not understand anything about the internal structure satellite receivers, or who has no time to deal with this at all, do not despair if the device breaks down. Service centers have not yet been canceled. There you can contact with your problem and experts 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 failure certain elements. This can also include breakdowns due to owners who themselves decided to sort 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 broken part of the receiver. The power supply can break due to a poor-quality power supply, due to poor-quality radio components (especially on cheap Chinese equipment).

Dust and dirt can also cause the receiving device to break down, creating incorrect thermal conditions.

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

AT service center repair and maintenance of 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. The timing of the repair will depend on the availability of parts in the service center. If any part is missing, it will be ordered from suppliers, which will take some time. But in large, serious centers, as a rule, parts are always available.

Consider another situation: the receiver failed after a power surge. After opening the lid, it was found that the following parts had burned out:

network capacity C5 - 47µFx400V

R8, R11, R13 - 3 ohms each (size 1206)

R9 - 47 Ohm (1206)

U1 - type not defined

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

We carry out the dismantling of defective parts (circled in red in the photo):

R8, R11, R13 - 3 ohm (1206)

R3, R6 (one of them is possible) - 1 MOm (1206)

C3-68nF

R25 - 3.6 kOhm (0805)

R26 - 10 kOhm (0805)

Installing new children

instead of U1 - SG6848

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

instead of C3 resistor 100 kOhm (1206)

instead of R26 resistor 33 kOhm

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

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

Installing new parts in the receiver

GS-8300 PSU Schematic

In this article, we will repair with our own hands "tricolor" receiver. Often there is such a problem that the warranty period has ended, and the receiver has suddenly broken down. Buying a new receiver is expensive, carrying it to a service center means depriving yourself of watching satellite TV. But in many cases, the breakdown of the device can be corrected independently, without spending much effort and large sums of money. If you know how to solder, then it is easier to figure out the malfunctions yourself and fix them.

We will use a television receiver as an example. It is worth noting that the quality of the receiver leaves much to be desired, as it costs decently. However, many subscribers use this particular receiver, and not all of them work properly.

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

So, a problem arose: the receiver does not turn on and does not show signs of life at all, and the indicators on the front panel do not light up. We tried to distort the plug from the outlet, turn on / off the toggle switch - it does not help.
Then we understand further. First, be sure to unplug the plug from the outlet and remove the top cover with a screwdriver. We need to look at the electronics 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 go in 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 rely on, then go ahead - break the seal.

Removing the cover reveals printed circuit boards with various components. They are interconnected by wires. The photo shows some devices with a description. We need to find the power board. It has a transformer and a supply for the power cord, so it is not difficult to find it. The first thing you should pay attention to 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 in which the fuse is placed. 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's blown, which often happens, then go to a radio store, buy the same fuse and just change it. If everything is fine with the fuse, then we check further down the chain.

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

Another malfunction is the failure of the electrolytic or oxide capacitor at the input due to drying out. To detect this breakdown, you need at least a little understanding of radio mechanics. A faulty capacitor is usually yellowish in color, and a small brown spot may be observed on the board at the base of its legs. In addition, you can compare the nominal and measured capacitance of the capacitor to determine its health.
The diode bridge in the receiver converts the alternating mains current into a direct one.

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 fault was detected as follows: we 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 fix the problem, and - "Hurrah! Earned! - Receiver is back to normal. Note that the transistor does not break often, mostly the receivers fail due to the fuse.

Consider another very common malfunction - firmware rally. This happens quite often. A sign of a firmware rally is the complete freezing of the receiver. Then we just need a receiver.

The reason for the failure of the receiver can also be poor-quality, unprofessional installation. If the outer insulation of the cable is broken, then rainwater or snow can easily penetrate the cable and, like a hose, seep into the receiver, flooding all its internal contents. Therefore, you need to monitor the cable, if there are any kinks or insulation violations.

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 yet been canceled. There you can contact with your problem and experts will help you solve it.

They fail for various reasons - this is a voltage drop, and the 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 sort 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 broken part of the receiver. The power supply may break due to a poor-quality power supply, due to poor-quality radio components (especially on cheap Chinese equipment).

Dust and dirt can also cause the receiving device to break down, creating incorrect thermal conditions.

The service center provides repair and maintenance of 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. The timing of the repair will depend on the availability of parts in the service center. If any part is missing, it will be ordered from suppliers, which will take some time. But in large, serious centers, as a rule, parts are always available.

Consider another situation: the receiver failed after a power surge. After opening the lid, it was found that the following parts had burned out:

• network capacity C5 - 47µFx400V
• Q1-CS2N60F
• R8, R11, R13 - 3 ohms each (size 1206)
• R9 - 47 Ohm (1206)
• U1 - type not defined

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

We carry out the dismantling of defective parts (circled in red in the photo):

• R8, R11, R13 - 3 ohm (1206)
• R3, R6 (one of them is possible) - 1 MOm (1206)
• C3-68nF
• R25 - 3.6 kOhm (0805)
• R26 - 10 kOhm (0805)

Installing new parts:

• instead of U1 - SG6848
• instead of R8, R11, R13 - one resistor 1.8 Om x 0.5W
• instead of C3 resistor 100 kOhm (1206)
• instead of R26 resistor 33 kOhm
• instead of R25, we select a resistor in the range of 10-12 kOm, controlling the voltage of 3V3 at the cathode VD8, we will stop at 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 - SSS4N60B (TO-220F case).

Video review: repair of the Tricolor GS8300 receiver (no signal)

———————

From June 28, 2011, all subscribers "", using the GS-8300, GS-8300M and GS-8300N receivers, need to update (software) via satellite to version 1.0.157.