J
Jason D.
Guest
I got this one here, complaint is dead, no LED, no HV.
Do have schematic for that.
The HOT isn't shorted yet SMPS looks like "cycling" like low power
mode or sleep and some of voltages like 15V are low, like 13V for
180V. Yet I have good standby power 5V for the micro controller.
Checking data bus for microcontroller by scoping the IC901's IIC buses
(pin 26 & 27) is constant data stream, Crytal is still workng. IIC bus
does repeats over and over.
Still, no LED at all, no horizontal pulses for the horizontal driver,
nor vertical pulses. The 15V feeding the IC605 is too low like (.9V)
for the external control 12V regulator switch (PQ12RF11) to work.
Couldn't find any shorts or not looking for short correctly.
I did unsolder most of loads (convergence IC, all LA6500, etc) except
for 180V feedback circuit for the power supply kept intact for safe
voltage regulation and left 5V standby alone.
Seen this type of failures before?
Help?
Cheers, Wizard
Do have schematic for that.
The HOT isn't shorted yet SMPS looks like "cycling" like low power
mode or sleep and some of voltages like 15V are low, like 13V for
180V. Yet I have good standby power 5V for the micro controller.
Checking data bus for microcontroller by scoping the IC901's IIC buses
(pin 26 & 27) is constant data stream, Crytal is still workng. IIC bus
does repeats over and over.
Still, no LED at all, no horizontal pulses for the horizontal driver,
nor vertical pulses. The 15V feeding the IC605 is too low like (.9V)
for the external control 12V regulator switch (PQ12RF11) to work.
Couldn't find any shorts or not looking for short correctly.
I did unsolder most of loads (convergence IC, all LA6500, etc) except
for 180V feedback circuit for the power supply kept intact for safe
voltage regulation and left 5V standby alone.
Seen this type of failures before?
Help?
Cheers, Wizard