Panasonic TC - 2188 color TV switching power supply due to increase the perfect protection circuit, the structure is complex, the maintenance difficulty is greatly increased, failure, do not know how to do often. In fact, as long as we truly understand understand, in the circuit to master some maintenance techniques, monitoring several key points of voltage, or it is not difficult to judge fault components. F9Rservice manual download site
First of all, let us analysis the TC - 2188 - s of switch power supply circuit principle diagram. We put the high voltage rectifier filter parts, oscillating voltage regulator, standby control, a low voltage rectifier filter, a protection circuit part separately, disconnect one element, make them relatively independent. And then according to the fault phenomena, determine the overhaul location, which can quickly judge the fault components, for easy maintenance. F9Rservice manual download site
 F9Rservice manual download site
 F9Rservice manual download site
When color TV switching power supply failure. The most common phenomenon is: (1) 3 without boot, light is not bright. (2) 3 without the boot flash indicator is destroyed. (3) watch the irregular automatic shutdown. (4) remote control switch machine failure. F9Rservice manual download site
When appear afore-mentioned troubleshooting, after open the machine cover, will first multimeter to R x 1 k file, with red pens and connect ground wire tube graphite layer, black pens and a pick up line deflection coil, measure the resistance value should be greater than 5 k and a capacitor charge and discharge phenomenon, that she did not breakdown, generally think failure in switching power supply part. F9Rservice manual download site
When maintenance, can according to the following steps: F9Rservice manual download site
One, will R834, R835 disconnect, D832 disconnect, parallel access on C835 60 w / 220 v bulbs as dummy load. Thus the line load disconnect, can safely access switch power supply. Try to electricity, if the light bulb not bright, suggests that fault is a part of switch power supply, can be carried out next overhaul. F9Rservice manual download site
Second, cut off protection circuit. Q826, Q827, Q804, photoelectric coupler D836, D811, diode D837, D830 D831, D832, D502, Q805 and peripheral circuit, over-current, + B overvoltage, loss of pressure protection circuit. Remove this part of the circuit, the switching power supply is not affected by any work. If there is no this part of the circuit, the power supply is much more simplified. Protection circuit of the actuators is Q804, remove it, after all the protection function failure.

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