After replacing R2, the device’s performance has been restored. Since the resistance between the 3.3 V power pins of the decoder chip and the circuit ground was ohms, it was replaced.
The supply voltage at the STi5119ALC decoder (3.3 V) is missing, the resistor R2 (1. Tuner does not turn on, voltage generated by the tuner power supply is normal The power key transistor Q1 was replaced with a more powerful type MJE13007. Replacing these elements led to the restoration of the tuner. The A1 (2 A) mains fuse is blown, the Q1 (MJE13003) key transistor, the U1 PWM controller (THX201) and the DZ1 zener diode (6.2 V) are also out of order. Additionally, in parallel with C1 (0.1 μF), an electrolytic capacitor with a capacity of 100 μF x 10 V was connected, which improved the sound quality of the broadcast programs.
It was eliminated by replacing the EC4 capacitor (10 μF x 16 V) in the DAC WM8725 circuit. The defect is manifested in the periodic appearance of the high frequency noise components in the sound The performance of the tuner has been restored after replacing the flash-memory and writing the reference firmware into it. The capturing of the Sti5518 decoder and Flash memory, as well as the control of the links between them, did not lead to positive results. It normally turned on when it was first started, but after entering the standby mode it became uncontrollable. Writing a working firmware to the U381 temporarily restored the performance of the tuner.
ALI M3329 D1 SOFTWARE VERIFICATION
The verification of the U381 Flash-memory (HY29LV160ATTC-90) showed the discrepancy of its contents in comparison with the reference firmware. The voltage generated by the power supply of the tuner is normal. When you turn on the tuner to the network, it does not switch to standby mode Defect is eliminated by replacing voltage regulator U151 (LM317) in the voltage shaping circuit +14/18 V. There is sound, image and OSD are missingĬhecking the voltage of +14/18 V, injected into the cable for reducing the power supply to the external converter, showed that it was normal when the cable was disconnected and was greatly underestimated - when it was connected. After replacing the U721, the malfunction was resolved. The supply voltage of the U721 chip (+5 and +12 V) is normal. Picture and sound are missing, OSD is displayedĪt the output of the decoder U301 (STi5518) (pin 32), the video signal is present, and at the output of the video switch U721 (AK4702VQ) (pin 3, 46) - is absent. After propaying resistors, the defect was eliminated. The oscilloscope control of the signals of the transport stream TS MPEG-2 from the channel selector BS2F7VZ0184 showed that they do not come through the resistors RA101, RA102 to the microcircuit of the STi5518 decoder. The on-screen menu (OSD) is displayed, the voltage of the external converter is normal. Due to the fact that many of these defects may occur due to damage to the microcontroller's control program, you should first try to repair it, as described in. It should be particularly noted that the material contains hardware faults in the tuners.
ALI M3329 D1 SOFTWARE HOW TO
Therefore, it will be very useful to have an idea about the symptoms of defects and how to eliminate them. Since many tuners are designed according to similar schemes, the defects of some models are similarly manifested in other devices. The article presents the typical and one-time problems in the author’s practice of satellite television (STV) tuners and how to eliminate them.
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