Electrical circuit of the dre 5000 receiver. Receiver power supply capacitors
Electronics repair Audio and video equipmentRepair of the power supply of the STV tuner DRE 5000
As already noted in, about 60% of all defects that arise during the pre-sale preparation and operation of STV tuners are associated with the failure of their power supplies. However, the operation of the STV tuner DRE4000 showed its “weak” unit - the power supply. DigiRaum has tried to improve the reliability of this unit, and a number of solutions have been introduced into the power supply of the new "DRE 5000" model to reduce the number of failures.
Rice. 1 Schematic diagram DRE 5000 tuner power supply
The schematic diagram of the power supply for the tuner "DRE 5000" is shown in the figure. First of all, it should be noted that all filter oxide capacitors in this model have an operating temperature of 105°C. The 5 V integrated voltage stabilizer on the KA7805 chip has been replaced with a stabilizer made on discrete elements, which increased the fault tolerance of this node. The PWM controller with an integrated key transistor U1 type L0380R has been replaced with a lower-power analogue DM0365R. The latest modification is most likely caused by the desire to reduce the cost of production of the device. The previous microcircuit was very reliable because it had a power reserve and good heat dissipation. The number of failures of this microcircuit was 1-2 per 30 repairs.
However, some defects were not eliminated. In particular, in positions D9 and C21 elements are used very Low quality. Several dozen devices with power supply defects have already been received for repair, which are largely associated with violation of the operating conditions of the tuner - instability of the supply voltage. Here are typical defects in the power supply of this tuner and the reasons for their occurrence.
The tuner does not turn on, the mains fuse F1 blows
Possible reasons:
One or more diodes D1-D4 are faulty (breakdown);
The power switch in the U1 controller is faulty.
The tuner does not turn on. Mains fuse F1 is OK
Possible reasons:
Loss of capacitance of capacitor C7;
Resistor R2 or R4 is broken.
The tuner does not turn on, mains fuse F1 is good. The voltage at the output of the power supply is underestimated
Possible reasons:
Fault U3;
Capacitor C21 is faulty (leakage);
Diode D9 is faulty (breakdown). It should be replaced with a more powerful one with a Schottky barrier (for example, 1N5822).
The tuner does not turn on, mains fuse F1 is good. Output voltages are underestimated. The network indicator is flashing
Possible reasons:
Diode D9 is faulty (breakdown);
Loss of capacitance of capacitor C3.
Literature
1. V. Fedorov. "Design and repair of power supplies for digital STV tuners." "Repair & Service", No. 5, 2007, p. 14-17.
Publication date: 22.05.2013
Readers' opinions
- Elena / 07/30/2015 - 13:09
The tuner began to hum... but it works well, but the second tuner hums the same way and creates image interference - Andrey / 05/18/2014 - 09:11
The power switch as part of the U1 controller flies away even with a GOOD fuse.
The satellite receiver, which is part of the recommended equipment “,” initially came with a defect. On the operator's TV channels, the image crumbles into small squares. The set-top box receives open TV channels without problems. This defect is associated with two faults. The manufacturer has produced over 7 million DRE 5000 receivers and is currently using this set-top box a large number of subscribers "". Therefore, the problem is very relevant. But don’t rush to buy a new receiver or run to a service center. Surely guarantee period your receiver has long expired. You will have to pay a decent amount for new equipment, experts service center They won't fix problems for free either. You can repair DRE 5000 at home. To do this, you will need a pair of new capacitors and a regular soldering iron; it is better to choose a thinner device.
Problem #1
The first malfunction lies in the 47uF X 400V electrolytic capacitor located in the power supply. For some reason it turned out to be swollen. The capacitor looks like it's about to explode. There is only one way to fix the problem - by replacement.
Let's disassemble the power supply. To do this, unscrew the bolts. If there is dirt, it must be removed immediately, since if it burns, a hole will form in the board. The performance of the device after such an incident is in question.
We remove dust using fluxophore, spray it and remove it with a brush. Dry the area using a regular soldering iron.
We unsolder the capacitor and throw it in the trash. Instead, we install a 400 V, 47 µF capacitor. Note! You can’t set it with less voltage, you can only use it with more, then there will be a small margin.
To improve the quality of soldering, add flux and solder in the next capacitor (10 V, 1000 μF or more).
We connect the receiver to the TV and the network. Let's check its work.
Problem #2
The second defect is ripple in the 5 volt power supply circuit of the DVB-S tuner. If you count from the antenna connector, then this will be the 5th leg. This circuit powers the STB6000 chip located inside the tuner. Next to it there is a place for sealing an electrolytic capacitor, but the capacitor itself is missing. Either the manufacturer decided to save money, or the human factor came into play and the developers forgot to include it in the set-top box. There is no need to dismantle and solder the capacitor. It is better to install it in a hinged way. An electrolytic capacitor 100 μF X 16V is soldered to the fifth leg and the picture does not crumble.
As you can see, you can diagnose and fix problems with the “” receiver at home. To do this, you do not need to have a technical education or certain skills. After such a repair, you will be able to stabilize the image, and sound problems will instantly disappear. The scale will not jump and you can enjoy watching your favorite TV channels.
In offline work. And now there are various articles about repairs household appliances there will be a lot.
Here is the first one on the topic of repairing household appliances. Although before that there were articles about repairing household appliances, I did it for myself. This one was already done in my workshop for repairing household appliances, and not at home.
They asked to look at the DRE 5000 satellite receiver. Well, since the petitioners were familiar neighbors, I went to their apartment to look at the satellite dish at the same time. Since there was a suspicion that the plate had moved and got knocked down. I checked the dish and cable from the DRE 5000 receiver and found no faults. When I turned on the DRE 5000 satellite receiver, a slight buzz appeared in the sound on the TV and the picture crumbled, that is, there were squares.
Well, from the hum it is immediately clear that this is a variable background. This means that the voltage is not filtered by the capacitor and the alternating voltage component creates a hum.
I told the owner that the DRE 5000 satellite receiver needed repair. I picked up the satellite receiver and took it to my parents to check it on their satellite dish. Since the DRE 5000 satellite receiver was set to Tricolor, but my dish is not set to Tricolor. There are 85 degrees and 75 degrees.
Satellite receiver repair
When turning on the satellite receiver, the same symptoms appeared: humming and tearing up the picture except for the STS channel, squares in the image. That is, definitely not anymore satellite dish is to blame, but the pure satellite receiver DRE 5000 has become unusable and requires repair.
I disassembled the receiver in the workshop. And immediately at the input of the power supply a swollen capacitor C3 was discovered - 47 microfarads at 400 volts. Look at the power supply diagram. The capacitor was most likely swollen due to a voltage drop in the network and therefore lost its properties. He simply didn’t call himself a tester at all.
I replaced the capacitor with a working one and again decided to check the DRE 5000 satellite receiver for sound and picture quality. The buzzing was gone, but the picture was blurry on most channels, but less so.
On the forums it was advised to remove the capacitor C5 - 100 pf at 1000 volts, since it and the capacitor and resistor next to it are filled with composite for some reason. Over time, the composite loses its properties and begins to conduct current. These parts overlap and the board burns out. The capacitor was removed and the board was cleared of the composite. Look at the photo. But these details do not affect the image and I began to dig further.
But everything turned out to be simple.
The tuner of the DRE 5000 receiver has an electrolytic capacitor that dries out over time and begins to work incorrectly. And you understand that the receiver is already old and out of production. This capacitor needs to be removed and soldered in its place with a new one, 220 microfarads 16 volts. It’s easier to solder the connector to the fifth leg of the tuner so that the tuner does not desolder from the board. Which is what was done.
I checked the DRE 5000 satellite receiver again for image quality. The squares disappeared and the signal from the dish and all channels were shown clearly. On this satellite receiver repair The DRE 5000 was completed and the receiver was handed over to the client.
Of course, for a certain amount...
And finally, laugh, watch the video...
The receiver was brought in for repair
Copyright Gertc.
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repair article DRE 5000. |
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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 ) |
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article on restoring and updating receiver software using RS-232 (COM) and JTAG, using DRE_4000,5000 as an example. |
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DRE-5000, DRE-7300, DRS-5001, DRS-5003 treatment using jtag. |
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DRE-5000 power supply diagram and possible malfunctions. |
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Repair 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 an operating temperature of +85 C, 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 I 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 the faulty protection elements: 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 is no leak 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, disconnecting resistor according to high voltage RV1, low voltage disconnect resistor RT1, D11, U1, check for open circuit primary winding T1.
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 the 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 of pictures, variable background in the image, hum in the background of 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!!!
SUPRA STV-LC42T400FL (V1N06)
Main HK.-T.SP9202P53
Backlight driver OB3350CP
Malfunction:
The backlight on the TV turns off, the sound and image remain, you can see it on the MENU matrix.
The backlight turns off randomly, the backlight may go out immediately, or it may work for half an hour. (according to the client)
In a workshop:
When it came in for repair, the TV worked for about 5 minutes and the backlight turned off.
The solution to the problem did not come immediately.
The first thing I thought of 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 with the device did not reveal an 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 me and caught my eye was that the area around the diodes was clearly burnt, more noticeable on some strips, less noticeable on others.
In general, I installed all the strips on the panel again and turned them on without a matrix! Oopss... The LEDs blinked and did not light up.
But before I disassembled 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, but I did not find any critical differences.
Well maybe? The TV worked, he personally took it for repairs 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 lights up green, that is, the TV remains in operating mode, you can turn it off from 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 the voltage on the OB3350CP driver again, everything is normal, except for the voltage on the 2nd leg, where it appears for a second and immediately disappears.
I decided that the problem was in the chip itself or in the LEDs. There was no such driver available, so I decided to replace the LEDs with new ones, fortunately I bought them recently.
Further, replacing the LEDs did not give any results, everything is the same, the backlight blinks and immediately goes out.
I bought two OB3350CPs, changed all two in turn, but the result was 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 put everything under a microscope in a circle.... everything is fine!
Only one resistor raised doubts; according to the marking it is 01C (10 kΩ), but when tested for Ohms it behaves strangely, either increasing or decreasing to the norm of 10 kΩ.
Once again I washed everything and soldered this resistor and finally it went to MΩ.
All repairs have been completed, the TV has been assembled and put into service!
In the photo I highlighted the problematic resistor; there was no circuit diagram during the repair, so it seemed to ring on the third leg of the OB3350CP.
In general, nothing new, whoever doesn’t work is not mistaken)) Just a repair..., I think in this chassis it will be another type due to the quality of the resistors marked 01C.
