From the camera's LCD monitor voltage indication and no charge " creak " sound analysis, to determine the initial oscillation circuit camera flash or no start-up oscillation control circuit failure .iqqservice manual download site
The camera flash by in-kind draw oscillation circuit schematic. The investigation found that the aircraft and trigger oscillation transformer coils are one, and the triggering element is not controlled by a switch , but by the thyristor VS1 control . Its flash oscillation circuit works : power, Manifold IC1 will send an oscillation control signal (2.7V £  triode V1 to the b -pole , transistors V1, V2, V3, V4 have been conducting work oscillation , the oscillation transformer the secondary high pressure is generated by C3 filter, diode VD1 to C11, C12 charging rectified when the flash is needed , press the shutter switch , manifold IC1 will send a trigger signal (1.5V), through resistor R7 to VS1 thyristor control electrode so that conduction through the primary circuit capacitor C1 is triggered thyristor and trigger coil discharge T2 , T2 generate high pressure in the secondary , inspired flash tube light. triode V1 first measured using the table of b -pole there manifold IC1 output of 2.7V control signal , and then measuring the transistor V2, each pole voltage V3, V4 , we found b voltage V4 is about 2.5V, suspected of V4 b, e knot open after removing the measure indeed open damaged, looking for a post- D809 transistor substitution failure remains. C11 measured by the voltage across the table is 2.5V, this time particularly hot to touch his hand transistor D809 substitution after checking other capacitors, resistors, etc. under normal circumstances components are basically determine the oscillation transformer T1 is damaged, there may be a short circuit between the high voltage coil turns . because there is no substitution of the same type transformers , put the original oscillation circuit pin adapter cable cut , with one of the other models oscillation transformer leads into circuit , the boot test , is still OK, but with the ends of the table have been measured C11 voltage of about 60V , transistor D809 too hot , indicating the oscillation circuit is basically working , but produces the voltage oscillation also insufficient to trigger the flash tube light. further careful analysis , the problem may be improper substitution oscillation transformer wiring , put the lead swapped again test machine , which heard the flash circuit oscillating squeak. etc. squeak disappeared, triggered by flash button , the flash tube lighting properly. because there is no patch switching transistor, see position between the circuit board and the cabinet can still accommodate , put D980 pin cut , then welded to the circuit board pin bends on in without removing the original basis of the oscillation transformer ( T2 trigger coil is good ), and the substitution of the oscillation transformer leads are connected and fixed spatial position in the larger chassis installed , flash work properly.

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