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Probleme TV PHILIPS sasiu L01.1E AB


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TV-ul l-am cumparat defect, la un pret mic, cu speranta ca voi gasi in el modulul digital care m-ar ajuta sa pornesc un TV Philips foarte asemanator (difera doar ecranul care este flat)... defapt, acest TV are nu doar ecranul diferit fata de cel pe care-l aveam inainte, ci si sasiul. Am incercat sa-l repar, si din cate am observat, a mai fost dus la un atelier de reparatii, deoarece are cativa condensatori electrolitici inlocuiti, se vede ca s-a intervenit pe pcb-ul de pe tub, s-a inlocuit CI TDA6107JF, s-a intevenit la potentiometrul "screen" (avea linii orizontale pe ecran, dar au disparut dupa ce i-am coborat tensiunea G2); Nu sunt avansat in domeniul depanarilor TV de aceea va cer dvs cateva sfaturi si sugestii. Televizorul porneste dar la scurt timp se decupleaza releul prin care se alimenteaza etajul linii. O alta problema este imaginea mai ingusta decat ecranul . Am incercat sa atasez si schema televizorului dar depaseste limita, are 8Mb. Va multumesc

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Tensiunea recuperata 13 V am masurat-o in timp ce aveam rastru pe ecran. este de 12,5V. Am inlocuit si cei doi tranzistori cu BC-urile care sunt mentionate in schema, la fel si condensatorul de 47Uf, insa nu s-a schimbat nimic. La scurt timp dupa pornire (aprox. 30 - 40 de secunde) dispare imaginea; porneste din nou doar la apasarea butoanelor P+ P-, apoi se opreste la acelasi interval de timp. o sa ma uit acum pe sasiul celuilalt TV poate o sa-mi fie bun TR linii si o sa-l inlocuiesc, poate o fi acolo problema. celalalt TV are sasiu Philips A02E AA

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Aici sunt date cateva detalii despre functionarea etajului 9.5.1 Horizontal DriveThe horizontal drive signal is obtained from an internal VCO,which is running at twice the line frequency. This frequency isCircuit Description EN 67 L01.1E AB 9.divided by two, to lock the first control loop to the incomingsignal.When the IC is switched ‘on’, the ‘Hdrive’ signal is suppresseduntil the frequency is correct.The ‘Hdrive’ signal is available at pin 30. The ‘Hflybk’ signal isfed to pin 31 to phase lock the horizontal oscillator, so thatTS7462 cannot switch ‘on’ during the flyback time.The ‘EWdrive’ signal for the E/W circuit (if present) is availableon pin 15, where it drives transistor 7400 to make linearitycorrections in the horizontal drive.When the set is switched on, the ‘+8V’ voltage goes to pin 9 ofIC7200. The horizontal drive starts up in a soft start mode. Itstarts with a very short TON time of the horizontal outputtransistor. The TOFF of the transistor is identical to the time innormal operation. The starting frequency during switch on istherefore about 2 times higher than the normal value. The ‘on’time is slowly increased to the nominal value in 1175 ms. Whenthe nominal value is reached, the PLL is closed in such a waythat only very small phase corrections are necessary.The ‘EHTinformation’ line on pin 11 is intended to be used as a‘X-ray’ protection. When this protection is activated (when thevoltage exceeds 6 V), the horizontal drive (pin 30) is switched'off' immediately. If the ‘H-drive’ is stopped, pin 11 will becomelow again. Now the horizontal drive is again switched on via theslow start procedure.The ‘EHTinformation’ line (Aquadag) is also fed back to theUOC IC7200 pin 54, to adjust the picture level in order tocompensate for changes in the beam current.The filament voltage is monitored for ‘no’ or ‘excessive’ voltage.This voltage is rectified by diode 6447 and fed to the emitter oftransistor TS7443. If this voltage goes above 6.8 V, transistorTS7443 will conduct, making the ‘EHT0’ line ‘high’. This willimmediately switch off the horizontal drive (pin 30) via the slowstop procedure.The horizontal drive signal exits IC7200 at pin 30 and goes toTS7462, the horizontal driver transistor. The signal is amplifiedand coupled to the base circuit of TS7460, the horizontal outputtransistor. This will drive the line output transformer (LOT) andassociated circuit. The LOT provides the extra high voltage(EHT), the VG2 voltage and the focus and filament voltages forthe CRT, while the line output circuit drives the horizontaldeflection coil.

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