Re: Sanyo DP42740 - Powers On, No Video - Missing 15/25v
If you have +72 volts (Vs) on pin #1 of P2 and NOT on Pin #1 of P11, You must have a broken trace as both points are connected together
Also on P11, Pin #4 you should have 15 volts
If Q407 C (tab) has 16 volts, check on the transistor next to it (Q30?), Its tab will 16 volts, then its emitter should have a similar voltage as its base, that emitter voltage should go up to the PFC ic's VCC pin
That 72 volts is low and should be 191 volts, again this is likely due to the low supply voltage (160 instead of 400) But the fact there is any voltage means a lot of the circuit is working.
Are you sure the voltage across the main filters (CE201/2) does'nt change from 160 volts to 400 volts when the tv is turned on?
If you have +72 volts (Vs) on pin #1 of P2 and NOT on Pin #1 of P11, You must have a broken trace as both points are connected together
Also on P11, Pin #4 you should have 15 volts
If Q407 C (tab) has 16 volts, check on the transistor next to it (Q30?), Its tab will 16 volts, then its emitter should have a similar voltage as its base, that emitter voltage should go up to the PFC ic's VCC pin
That 72 volts is low and should be 191 volts, again this is likely due to the low supply voltage (160 instead of 400) But the fact there is any voltage means a lot of the circuit is working.
Are you sure the voltage across the main filters (CE201/2) does'nt change from 160 volts to 400 volts when the tv is turned on?
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