The Globo receiver does not turn on, the voltage is too low. Technical malfunctions of the receiver

This article is dedicated to satellite receivers , or rather repairs their power supply.

Satellite receiver power supply repair

Breaking satellite receiver power supply – one of the most common causes of device malfunction. This is due to the fact that the receiver is constantly connected to the network, as a result of which rapid wear of various parts becomes inevitable.

Diagnosing a power supply failure is quite simple. The receiver either shows no signs of life at all, or blinks one indicator, but does not function. It is not uncommon to see a flashing display. Depending on the model and type of failure, the symptoms may vary, but in any case, it is better to start diagnosing the device with the power supply.

Visual inspection

Before starting work, the receiver must be disconnected from the network. Then you need to disassemble the device case and clean the board from dust (perhaps this is the problem). It is not necessary to immediately take up a multimeter and an oscilloscope (especially if you simply don’t have them). The most common failure can be diagnosed with the naked eye: a faulty capacitor.

A failed capacitor, as a rule, is characterized by a swollen top part. In some cases, the capacitor may leak, which, again, is easily detected by external inspection. Having noticed this, you need to immediately unsolder the capacitor and solder in, observing the polarity, a new one with similar parameters.

It is also easy to identify a blown fuse. It should also be replaced with a similar one, because without it, in principle, no voltage is supplied to the power supply. If after the described procedures the receiver still does not work, you need to take measurements.

General measurements

First you need to measure all the output voltages from the power supply. As a rule, their values ​​are marked on the board next to the corresponding contacts. If all voltages correspond to the declared ones, then, obviously, the power supply is in order, and the problem lies further. If the values ​​differ, then the fault is still in the power supply.

You can use an oscilloscope and check what type of current we have at the output. If the voltage is constant, then most likely the problem is in the smoothing capacitor. If the variable is in the diode bridge. Important! The described measurements must be made with the receiver connected to the network!

Spot measurements

You can do without an oscilloscope by simply “calling” all capacitors and diodes with a multimeter. A faulty capacitor does not necessarily look swollen; it may not differ in any way from a normal, working one. Accordingly, its malfunction can be detected only by measuring the internal resistance.

Also, the fault may lie in the high-voltage part of the circuit. As a rule, these are diodes. You need to “ring” each one and, if necessary, resolder the diode bridge. Even if only one diode has burned out, all four should be replaced. It is possible that the diodes “burn out,” temporarily remaining operational, but fail in the near future. In addition, you should check the resistance of all resistors.

Other cases

In rare cases, it may happen that the throttle fails. This is one of the most problematic parts. Finding a new throttle will most likely not work. You will have to use the service of a “donor” if possible. Fortunately, such breakdowns do not happen very often - during strong power surges in the network.

The PWM controller may also burn out. This is the last thing you should sin on if everything else has already been replaced or was working. Can be replaced, finding a new one is not difficult.

repair article DRE 5000. Inside the article_DRE_5000 circuit: power supply, fragment of the channel selector interface.

article on the design and repair of power supplies some receivers. Inside the article there are diagrams: “HUMAX F1/CI/VA/VACI”, “Strong SRT4450”, “Sky Way 6000”, “DRE-4000” (as well as characteristic defects of the “DRE-4000” power supply and how to eliminate them )

article on restoring and updating receiver software using RS-232 (COM) and JTAG, using DRE_4000,5000 as an example. Inside there is a connection diagram via COM, 2 JTAG options (wiring and electrical diagram)

DRE-5000, DRE-7300, DRS-5001, DRS-5003 treatment using jtag.

DRE-5000 power supply diagram and possible malfunctions.

Repair of satellite receivers with a defect - “no signal”, flooded with rainwater via a cheap Chinese cable.

Most of the defects that occur during operation of STV tuners are associated with the failure of their power supplies. Power supplies of this type They fail mainly due to power surges, low-quality components and are very afraid of static voltage. I will give an extract from the article by V.K. Fedorov. “Repair of satellite receivers” in the supplement to the magazine “Repair & Service” 2010. – unfortunately, during the development of power supplies for receivers of these brands (DRE), a number of mistakes were made that led to their failure. For example, capacitors C 9, C12, C15, C19 and C20 have operating temperature+85C, and a very low quality diode is used as D9. As a long-time user of Tricolor TV and its receivers DRE-4000, DRE-5000, DRE-5001, I often go to the Telesputnik forums. Several times the advice from the “Power Supply Repair” section helped me repair receivers for myself and my neighbors, so I decided to summarize the faults mentioned in this section. Before repairing the receiver, make sure that the satellite antenna is configured correctly, the receiving converter, cable and antenna switch are working correctly, or check the operation of the receiver for known working system.

Warning

1. If the receiver stops loading or is loading longer than the previously set time, immediately look for the reason - you can kill the crypt module.

2. Pull out the crypt module before starting the repair, it will work and put it in place.

1.press (Menu) on the remote control, select “Settings”, press (OK) and enter the PIN code (default 0000).

2.Select “Factory Settings” from the menu and press (OK). A warning message will appear on the TV screen about complete removal all settings made by the user.

3. Press the red button at the bottom of the remote control. A request will appear on the TV screen to delete all user data.

4. To select “Yes”, press the (Left) button, then press “OK”. The receiver deletes data for about 15 seconds, during this time it is strictly forbidden to turn off the power of the receiver and perform any actions with the receiver - this can lead to incomplete or incorrect recording of data in the flash memory of the receiver and its breakdown.

If the set PIN code is unknown, you can reset it to 0000.

To do this, press (Menu) and select “Status”. A window with the receiver data will open, then successively press the following buttons on the remote control:

white , (9 ), yellow, (4 ), red, (8 ), (7 ), (3 ), (5 ), green.

A window will appear with the question: “Change PIN. Are you sure?. Select “Yes” by pressing the “Left” button.”Confirm resetting the PIN code to 0000? by clicking the “OK” button.

Receiver power supply capacitors

	0.1uF 275v		470uF 16v
	0.1uF 275v		2200uF 500v
	47uF 400v
	0.01uF 500v		100uF 25v
	100uF 1000v		1000uF 25v
	CL-112A333J0.033uF100v		1000uF 10v
	47uF 50v		1000uF 10v
	CL-112A333J0.033uF100v		470uF 16v
	10uF 50v		10uF 50v
	1uF 50v		0.1uF
	470uF 35v		2200uF 2kv

Receiver power supply resistors

	1mohm +\-5%		10com +\-5%
	100com +\-5%		10com +\-5%
	27com +\-5%		10com +\-5%
	10ohm +\-5%		10com +\-5%
	1com +\-5%		6.8com +\-5%
	2com +\-5%		1com +\-5%
	2.2com +\-5%		1com +\-5%
	10ohm +\-5%		5.6com +\-5%
			4.7com +\-5%
	100ohm +\-5%

I will give the markings of the remaining components of the power supply of the DRE-5000,5001 receivers.

The markings may not coincide with the data shown on the diagrams; copied from real power supplies.

Power supply failure No. 1

Signs:

The receiver does not turn on, there are no messages on the front panel indicator, no picture or sound.

Possible reason:

The power cord is broken, the power supply protection system has tripped.

Actions:

Check the presence of 220 V supply voltage at the input of the power supply; if not, replace the cord or switch;

Check the presence of 220 V supply voltage on capacitor C 1, if there is no voltage, replace it faulty elements protection: RV1, RV2 and fuse;

Check the presence of 220V supply voltage at the output of inductor LF1, if not, replace inductor LF1;

If the mains fuse blows, check that there is no breakdown of the protection elements: RV1, C 1, C2. Check rectifier diodes. Then make sure there are no leaks or short circuit in the high-voltage capacitor C 3 and in the U1 microcircuit;

If the mains fuse is intact, then check the presence of all voltages at the outputs of the power supply 3.3; 5; 12; 22 and 30 centuries. Then disconnect the power supply connector from the main board of the receiver and measure the voltage again. If the power supply works successfully, then check the serviceability of the components of the main board of the receiver;

If one or more voltages are missing, check the corresponding circuits of the power supply;

If there is no voltage at the output of the power supply, check the presence of a rectified voltage of 300V at the terminals of the electrolytic capacitor C 3, make sure that there is no break in the resistor R2 in the power supply circuit of the U1 microcircuit;

Make sure that diode D5 is intact and resistor R4 is not broken;

Check the serviceability of optocoupler U2, controlled zener diode U3 and zener diode VDx (may be missing in some power supply models);

Make sure the integrity of diodes D5-D10 in the low-voltage part of the power supply;

Make sure there are no leaks, breaks or short circuits in electrolytic capacitors C9, C11, C12, C15-C20 (it is advisable to replace capacitors C16, C17 and C11 immediately, regardless of their appearance); - check the integrity of chokes L1-L4.

Power supply failure No. 2

Signs:

The receiver does not turn on, there are no messages on the indicator;

The receiver turns on, but turns off after a few seconds. The indicators flash and “8888” is displayed.

Possible reasons:

power supply protection has tripped.

Actions:

check the serviceability of diodes D5-D10 in the low-voltage part of the power supply;

Make sure there are no leaks, breaks or short circuits in electrolytic capacitors C 9, C 11, C 12, C15-C20 (it is advisable to replace capacitors C16, C17 and C11 immediately, regardless of their appearance);

Check the serviceability of optocoupler U2, zener diode U3 and zener diode VDx (may be missing in some power supply models);

Make sure that diode D11 is in good condition and that there is no breakdown or leakage in capacitors C4 and C5.

Make sure there is no short circuit in the windings of transformer T1;

Replace chip U1.

Power supply failure No. 3

Signs:

The receiver turns on, but after 20-40 minutes it turns off or the indicators on the front panel of the receiver begin to blink.

Possible reasons :

the power supply protection system is triggered.

Actions:

Make sure that diode D11 is in good condition and that there is no breakdown or leakage in capacitors C4 and C5;

Replace faulty electrolytic capacitors and/or diodes in the low-voltage part of the power supply, usually in the 3.3V and 5V circuits.

Replace U1 chip .

Power supply failure No. 4

Signs:

Uncertain signal reception; - the picture on the screen crumbles into cubes, especially when viewing encrypted channels;

The readings on the “Quality” and “Power” scales change chaotically.

Possible reasons:

Loss of capacity or break of the high-voltage electrolytic capacitor in the high-voltage part of the receiver's power supply;

Loss of capacitance or break of the electrolytic capacitor in the tuner power circuits (pin 5).

Actions:

Replace the faulty high-voltage capacitor in the high-voltage part of the power supply;

Replace or install, if missing, the capacitor on the 5th leg of the tuner.

Power supply failure No. 5

Signs:

Smoke comes from the receiver, sometimes sparks are visible between the parts on the board;

The indicators on the front panel of the receiver are flashing.

Possible reasons:

Triggering of the power supply protection system due to breakdown of capacitors C4 and C5;

Breakdown of the paste between capacitors C4 and C5.

Actions:

remove remaining paste and carbon from the board and parts, wash the board, replace faulty parts.

"Dead Receiver" - check fuse F1, high voltage breaking resistor RV1, low voltage breaking resistor RT1, D11, U1, check primary winding T1 for open circuit.

The fuse has blown - look at RV1, diode bridge D1-D4, C3, C1,

The outputs of the power supply are zeros– look at U1.

The receiver does not turn on– look at U1, C17, C18, C11, C16.

The receiver goes into reboot– look at U1, C17, C3.

When turned on, the indication “Standby» - look at C3, C17, C18.

All display segments flash- look at C17, C18.

Indication "8888"– look at C3, C17, C18.

The voltages at the outputs of the power supply are underestimated and jumping– look at D6, D7.

The power supply underestimates output voltage – look at U3, C12, C17, C21, D9.

The power supply overestimates the output voltage– look at C17.

There is no 30v or 22v at the output– look at D7, D10, C5, C22.

There is noise on the screen in the form of horizontal light stripes running upward– look at C3, U1, C12, C15, C16, C17, C18.

There is no signal on tricolor frequency– look at C17, C18.

Scattering pictures variable background in the image, hum in the background sound– look at C3, C7, C8, C18.

Transformer clicking, red LED flashing– check D5, R, C7, then D11, R3, check the diodes of the secondary circuit and check the winding of transformer T1 for an open circuit.

The list of faults will be updated.

From my experience: The remote control for these receivers can be replaced with a remote control from HUMAX. The same applies to the universal type SURC-8148L (for $7) and the like)) - the setting code on the remote control is selected by auto-selection (I have attached instructions from the SURC remote control in RUSSIAN).

The universal one is more convenient than the native one, the buttons are not immediately erased. SURC.doc (87.5 Kb)

Much work to your receiver!!!

Hello, today we will try to fix the Tricolor receiver. 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 company GS-8300 N. I must say, the device is not the most best quality, and the money he 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.

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 a short circuit in the circuit, although 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 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 the warranty seal, which we will certainly break if we remove the cover. Therefore, make sure once again that guarantee 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 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 supply 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 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 First level radio amateur. Typically, faulty capacitors are swollen, have a yellowish appearance, or have 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 it will help. I’ll tell you about another reason for the 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; it easily gets into 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.

Sooner or later, but most household radio-electronic equipment fails. In relation to satellite equipment, the reasons for this may be the same factors as for other electronic technology: aging of radioelements during operation (for example, “drying out” of electrolytic capacitors); external influence on elements of the entire satellite system(water getting into the connectors and cables of the antenna-feeder system, the electronic part of the motor suspension or actuator, converters, etc.); incorrect software installation; failure of the receiver's power supply due to poor-quality supply voltage (voltage surges), etc. - It makes no sense to list all the factors, of which there are a great many.

Let's take a closer look at some of the repair details. If the receiver works, but incorrectly, then at the beginning of the repair you should first check (or reinstall) all the necessary software settings of the equipment. If this does not help, we proceed to check the antenna-feeder path - we check the installation of the antenna (if it has moved, there is no damage or deformation). Next, we check the converter and supply cable.

The converter can be checked using Satfinder or another receiver - if there is a problem with it, you will have to spend money on buying a new one (although some, especially inquisitive DIYers, manage to saw through the internal silumin body of the converter and get to its insides). I would especially like to draw attention to on choice antenna cable- the use of low-quality (China or Poland) antenna cable type RG-6U can lead to very serious consequences.

This cable does not stand up to any criticism - the outer insulation can be torn off by hand, breaking the insulation in at least one place leads to the fact that the inner sheath of the cable is filled with water! The use of bimetal as a central core material leads to corrosion in the first season. As a result of exposure external factors The cable may fail within a week (there have been cases!) after installation. Professionals in the field satellite reception They will advise you to use a cable from the Italian company Cavel, which is an order of magnitude more expensive than a proven cable from domestic manufacturers, which is also suitable for use.

Checking the integrity of the cable is not difficult if you have a multimeter. So we checked everything external elements satellite system. If everything is in order, then you can safely proceed to the main thing - repairing the receiver. First of all, it should be mentioned that incorrect operation of the satellite receiver can occur due to a firmware crash (rarely, but it does happen) or its incorrect operation. In this case, flashing the receiver with new software can help us. To do this we need a null modem cable, a bootloader and the actual software. We talked about how to make a null modem cable in the chapter on. Loading software into the receiver is an individual procedure for each individual model, and we will not focus on this. One more software malfunction receiving equipment, maybe software glitch when flashing or incorrect firmware. In this case, the receiver does not respond to any external installations. This happens due to the impact on the internal memory of the receiver's bootloader, or its erasure (for example, erase or incorrectly install BIOS settings your computer and see what happens). Resuscitation of such a “dead” patient is carried out through the use of JTAG - a specialized programming protocol and internal debugging of the receiver’s resources using a specialized JTAG programmer. It's worth mentioning that this procedure- the domain of either professionals or fairly advanced users - there is a risk (if incorrect operation) completely ruin it. Next, let's move on to discussing physical malfunctions of receivers.

The most common malfunction of the receiver is a malfunction of the power supply, as the most unreliable part of any electronic equipment. The power supply generates voltage for power supply internal circuit receiver as well as for powering external LNB units and electric drive (if one is installed). We begin repairing the power supply by checking the fuses and protective breaking resistors. The burnout of these parts does not necessarily indicate a malfunction of the circuit - perhaps this occurred as a result of a surge in the network alternating current, or these parts initially had a manufacturing defect. If the problem cannot be eliminated, we begin to “digging” further. To do this, let’s look at the operating principle of a pulse power supply in a block diagram.

In a UPS, the AC input voltage is first rectified, then supplied to power the controller and converter, with the help of which constant pressure converted into rectangular pulses with a given (increased) frequency and duty cycle, supplied to the transformer. One of the output windings (UN) is used for control - depending on the voltage in it, the PWM controller changes the frequency and duty cycle of the pulses in the high-voltage winding (HV). This maintains a stable output voltage. The UPS has another type of parameter control (PV) - voltage control for powering the digital part of the receiver - the processor and memory. The control voltage is supplied to the PWM controller through an optocoupler (OP) for galvanic isolation from the high-voltage part of the power supply. The output voltages from the low-voltage windings of the transformer (LV) are supplied to rectifiers and stabilizers. A voltage of 24-33V is required to bias the varicaps in the RF tuner module; 12V is needed to power the analog part of the circuit (video and sound); 5 and 3.3V - to power the digital part of the circuit. Troubleshooting begins by checking the diodes in the high-voltage part of the circuit. Diodes in the low-voltage part of the circuit are also susceptible to failure. They also check resistors (for open circuit) and capacitors (break, swelling) in all parts of the circuit, stabilizers of low-voltage circuits, and Schottky diodes. It should be remembered that diodes may appear to be working properly, but have leakage current. If this search does not lead to anything, and troubleshooting the transformer windings and chokes also does not bring results, then we can say with confidence that the PWM itself and its wiring elements must be replaced. It should be recalled that often the malfunction can be a lack of solder at the connection points of the power supply winding parts - loosening of the contacts occurs due to vibration of the elements on operating frequency power supply. Finally, a little technical advice. You should be very careful when choosing satellite equipment- the market is simply flooded with fakes famous brands. You don’t have to look far for an example - in the recent past, a device called Boston passed through my hands, which was an almost complete copy of the Korean Openbox brand receiver. After not working for even a month, the device broke down. Conclusion - before purchasing, carefully study the device, check the manufacturer, and don’t be lazy to look for information about satellite receiver on the Internet (reviews, licenses). Speaking of licenses, equipment manufactured in mainland China is quite reliable in operation, just don’t run into an outright fake made in an unknown location.

The equipment of European manufacturers in this regard is of course beyond competition (compared to Chinese) - shown in the picture (with with the lid removed) a simple receiver from the German company Golden Interstar has been working in my dacha for many years without repair. Take into account all the above criteria for choosing equipment and you won’t have to repair it!

Hello guests and blog readers! Almost every resident now has a satellite dish. And the problem of failure of its elements, such as the converter, receiver and antenna feeder, does not bypass it. In this article we will try to consider the main malfunctions of satellite dishes.

Satellite receivers need to be repaired much more often than converters. This is due to the low quality of receivers made in China.
The main reasons for failure of receivers are drying out of electrolytic capacitors, failure of the converter, damage and precipitation entering the antenna-feeder system (cable), damage firmware receiver and failure of the receiver's power supply as a result of a power surge, etc.
What are the nuances for repairing satellite receivers? If the receiver works, but is “buggy”, then you first need to check and, if necessary, reinstall it software settings. If this does not help, you need to check the antenna-feeder system (whether the antenna has moved). Then you need to check the converter and the cable connecting it to the receiver. It is better to install a converter that is known to be good for testing.

I would like to draw attention to the quality of the cable used in satellite dishes. This should be given some attention Special attention, since the use of low-quality cable often leads to serious consequences.
If damaged outer shell The inner cable is filled with water. And this in turn causes corrosion of the internal core and rapid deterioration of the cable. Therefore, I do not recommend installing a cheap Chinese cable.
You can check the cable with a simple multimeter. And if after all these checks no image appears on your TV screen, then move on to the main element of the satellite dish - the receiver.

Very often, the cause of a satellite receiver malfunction is a firmware crash. In this case, only flashing it will help. Here you will need a null modem cable, a bootloader, software and experience in flashing receiver firmware. If you do not have such experience, then entrust this matter to professionals. Otherwise, you can completely ruin your receiver and it will be very difficult to restore it.

Let's look at some common receiver malfunctions, and or rather a faulty power supply.
The power supply is the most unreliable element of any electronic circuit. The durability of the entire electronic content of the receiver depends on the stability and magnitude of the supply voltage.
And so we’ll start repairing the power supply by checking the fuse and protective resistors.
Protective resistors burn out for a reason. The main reason is overload and power surges. If, after installing serviceable parts, the power supply does not begin to function, then we move on.
In a switching power supply, the mains voltage is rectified and supplied to power the converter and power controller. The converter converts rectified voltage into current high frequency and feeds it to the transformer. The transformer winding has several parts. One part is used for control. The PWM controller measures the voltage on it and changes the duty cycle and frequency of the pulses supplied to the primary winding of the transformer. This ensures maintaining a stable output voltage.

In a switching power supply, control is also carried out for the supply voltage digital circuit receiver (processor and memory).
The voltage is supplied to the PWM controller through an optocoupler. This makes it possible to implement galvanic isolation with the high voltage part of the circuit.

From the additional and main secondary windings, voltage is supplied to rectifiers and stabilizers.
Voltages from 24 to 33 volts are required to supply bias to the varicaps of the high-frequency tuner.
A voltage of 12 volts is supplied to power the analog part of the receiver circuit (sound and video).
A voltage of 5 and 3.3 volts is necessary to power the digital chips of the receiver.

Troubleshooting the receiver

Troubleshooting should begin by checking the diodes in the high-voltage part of the circuit pulse block power supply and low voltage. Also check the resistors for open circuits and the condition of the capacitors. If they have tears or swelling, they must be replaced immediately. Electrolytic capacitors dry out quickly and lose their rated capacity. And this leads to inoperability electrical diagram generally.
Check voltage regulators and Schottky diodes.
When checking diodes digital multimeter they may turn out to be serviceable, but have leakage current. This is unacceptable and often leads to malfunctions. Keep this in mind.

If troubleshooting is unsuccessful, then you should pay attention to the PWM controller and its wiring diagram. Replacing it (microcircuits) often brings the receiver back to “life”. Check the winding of the transformer and chokes for breaks.
Another cause of the malfunction may lie in the failure of the contact legs of the switching power supply transformer. Sometimes you can't see the hole with the naked eye, so use a magnifying glass. Be sure to solder all suspicious places. Repairing a satellite receiver may take you a very long time, but after the repair you will gain experience.
And one more thing I would like to say. Don't buy suspiciously cheap ones satellite receivers. You may run into a fake that won’t work for a month. Good luck with the renovation and bye!