Hi all,
been asked to look at a friends old Sony which turns on ok, changes channels and has backlight and volume control etc. yet just displays grey, with a few streaky lines across the screen.
A quick test revealed that the voltage across the T-Con cable connector(CN6151) on the PSU (G2) was missing, although the 3.3v 'T-CON_On' and 'T-CON_Vcc12v' were present at the connector which links to the main board (CN6150).
As they live some distance away I took the PSU with me to see where the problem might lie.
I'm presuming that the 3.3v needs to be connected to both the 'POWER_On' and 'T-CON_ON' in order to for the area in question on the board to stay 'live'?
There is not a lot of circuitry between the two connectors, with a FET and a couple of transistors after the secondary of a transformer, but my concern is whether the PSU might be damaged with no load?
I'm not a TV tech but want to know if there is likely to be any problem if I power the board up without any load?
Enclosing the schematic and a couple of photos of the suspect area if anyone is interested
been asked to look at a friends old Sony which turns on ok, changes channels and has backlight and volume control etc. yet just displays grey, with a few streaky lines across the screen.
A quick test revealed that the voltage across the T-Con cable connector(CN6151) on the PSU (G2) was missing, although the 3.3v 'T-CON_On' and 'T-CON_Vcc12v' were present at the connector which links to the main board (CN6150).
As they live some distance away I took the PSU with me to see where the problem might lie.
I'm presuming that the 3.3v needs to be connected to both the 'POWER_On' and 'T-CON_ON' in order to for the area in question on the board to stay 'live'?
There is not a lot of circuitry between the two connectors, with a FET and a couple of transistors after the secondary of a transformer, but my concern is whether the PSU might be damaged with no load?
I'm not a TV tech but want to know if there is likely to be any problem if I power the board up without any load?
Enclosing the schematic and a couple of photos of the suspect area if anyone is interested
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