Core tips£ºKonka VW5001 TV convergence without memory
A memory on the digital convergence Board ICllO (electric schematic diagram of Iclll on the actual drive is not used), which is composed of ICl05 (CM0021 AF) of digital convergence output chip ¢Þ ¢ß foot "SDAM," "SCLM" bus control, as shown in the figure. ICl05 II foot output is "write protected" (active low). Also RCl22, RCl65, RCl66, known as the "pull-up resistors", by the "connector" Pcl05 "(16) foot into a 5V power supply IcllO ¢à feet via the zcl05 inductance added to memory, and sadly, via the pull-up resistor is added to memory, ¢Þ ¢Ý feet. Thus, convergent memoryless, that is finished and press "memory" key cannot be saved. For BT430l machine,, we to note to figure 50 by to out of another a group relationship, that switch SCl02 in machine and Pc machine phase Shi reset "4", and "3" bit, dang TV watch Shi is reset ¢Ù, and II bit of, such digital converge Icl09 (small CPU) Krispy Kreme, and ¢â feet made I ¡æ bus of main controlled device through Rcl68 (100 ω), and Rcl69 (100 ω) received Yu Icl05 of (18), and (19) feet, then and from ¢Þ, and sadly feet to control ICll0. Above is actually pointed out the convergence memory fault-free areas are: Icl09, Scl02,Icl05,IcllO switch and power supply, the pull-up resistor.
After measuring ICl05,ICl09,ICll0 feet there is no normal power supply from the power supply then measure the bus voltage is normal, check measuring scl02 contact is good, finally going to adjust the data transmission path, namely Icl05 (12), (13) and the Ic109 (19), (20) feet. Had the fault location of fault in the maintenance department and a Rcl74 cold solder joint, making the Icl05 comparator a is the adjusted data in Icl09 (19) foot; one is RCl66 foot short circuits, resulting in ICl05 and ICllO serial clock error; one is tool-poor contact switch Scl02, Icl09 and Icl05 bus lost control. After the deal, three machines are normal memory (Note: there are a number of factory machines, due to software changes, such as possible "without memory", but the "key point" voltage are normal, Rcl22 is 5. 1 k, can be changed to 10K).