Panasonic TC-M25C TV light, no map, silent fault repair method |
| Time£º2014-05-25 06:50:50 Source£ºNetwork Author£ºUnknown Clicks£º1435 |
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tdhservice manual download site
tdhservice manual download site
At this point, maintenance in trouble. tdhservice manual download site
tdhservice manual download site
In no doubt where there is no way, under the condition of the machine down, reviewing, the process of inspection found each moment switched on insurance tube F801 burning, burning degree is not the same. Sometimes a boot F801 that all insurance tube fuse fusing; Sometimes machine has no reaction, just insurance tube fuse slight fracture; Another time, as previously mentioned insurance F801 didn't burn. From the detail analysis of failure performance, power filter, degaussing circuit boards must be soft breakdown phenomenon, and every time varying degrees of soft breakdown. So what exactly is which element soft breakdown? According to many years maintenance experience and their own master data, usually more than soft breakdown performance in three phase meter, degaussing resistor and capacitor element, and only five power grid on the cell plate filter coil, seven capacitor, a degaussing resistor and a 5 w power resistor R847, a grid in parallel with the 1/2 R892 w resistor, degaussing resistor has been replaced twice, 7 capacitor and R892 through the adoption of a variety of ways over checking also didn't find out problem, high-power resistance soft breakdown phenomenon has not met, also didn't heard of, don't is a 5 w 120 Ω high-power resistance R847 soft breakdown? Try to be removed, measure the resistance value is normal, because you don't have this specification resistance, adopt emergency measures temporary string into the degaussing circuit, degaussing resistance to boot after troubleshooting. Will on the degaussing resistance access degaussing circuit, also all is well. Looks like is R847 fault. tdhservice manual download site
tdhservice manual download site
In order to further verify the 5 w 120 Ω high-power resistance is R847 really soft breakdown, the author did an experiment, will remove the R847 and after a 40 w bulb series connected to the mains bulb light to normal. The multimeter ac 250 v gear measuring bulb actual voltage of power grid voltage is 190 v, and voltage is almost zero resistance, power measurement with multimeter R x 10 after the resistance of 120 Ω. Identify the R847 is really soft breakdown.
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