Hello to everyone, i have a problem with this Sony LCD
Sony KDL-37W5500
Chassis EX2L
MAINBOARD: 1-878-942-22
PANEL: T370HW02
Audio Amp: TAS5602
Sound System: CXA3785R-T6
main CPU: EMMA3 (under heat sink should be MB91F313APMC-GE1)
Power Supply: G4, MB91F313APMC-GE1
When i try to turn it on it clicks relay, blinks 1x Green Led, then it shuts down and blinks 8x Red Led.
Looking at service manual it should be an Audio Error. When i try to enter Self Diagnostic Menu it just wont light up the screen. I do the sequence "I+" "5" "V-" "Power" and it powers up regularly 1xgreen 8x red, black screen.
From power supply i get all the voltages, except that 15V is 17.4V constant, but at the moment of powering it overshoots at 24V briefly.
Also i don't get D3.3V voltage. I have 12V on regulator BD9540EFV, but enable pins 3 and 12 are held too low on 1.6V, and it need at least 2.2V to enable output, so i dont have 3.3V, only 0,7V.
DVDD 3.3v is logic supply, so i dont get how CPU gets logic levels from ICs when there is no Logic Supply...
When i measure the power for audio amplifier TAS5602DCAR it should be 13V i suppose, but it gets 17.4V, from the CON1300 pins 4 and 5. It is ok for that IC, it works on voltages until 30V, but I worry if that does not affect some other processes.
Fault signal from audio amp is on PIN19 and it is 3.3V that is HIGH and it suggests Normal Operation.
On sound system IC CXA3785R-T6 pin44 the VFAULT signal is LOW 0.7V, that is too normal operation.
But on audio amp pin18 RESER is held in LOW and it does not go to HIGH to get out of the reset mode. That pin is controlled by main CPU signal X_SP_Mute.
On sound system IC CXA3785R-T6 pin43 X_Protect output is LOW 0.4V that means ERROR.
In datasheet it says X_PROTECTOUT outputs “L” when input voltage (SPxP/N) become under 3.0V.
That is on pins 61-62 and 63-64, and if I understand right it needs to have 3+ V DC to output High Normal signal?
Isnt that a bit too high to have on speakers? I measure 0V DC there, and 25mV AC.
What do you think can be the main problem and solution for this ?
I exclude replacing whole board
This is the board picture, service manual and datasheets for ICs
https://cdn.badcaps-static.com/pdfs/...4ea5bf553a.pdf
Sony KDL-37W5500
Chassis EX2L
MAINBOARD: 1-878-942-22
PANEL: T370HW02
Audio Amp: TAS5602
Sound System: CXA3785R-T6
main CPU: EMMA3 (under heat sink should be MB91F313APMC-GE1)
Power Supply: G4, MB91F313APMC-GE1
When i try to turn it on it clicks relay, blinks 1x Green Led, then it shuts down and blinks 8x Red Led.
Looking at service manual it should be an Audio Error. When i try to enter Self Diagnostic Menu it just wont light up the screen. I do the sequence "I+" "5" "V-" "Power" and it powers up regularly 1xgreen 8x red, black screen.
From power supply i get all the voltages, except that 15V is 17.4V constant, but at the moment of powering it overshoots at 24V briefly.
Also i don't get D3.3V voltage. I have 12V on regulator BD9540EFV, but enable pins 3 and 12 are held too low on 1.6V, and it need at least 2.2V to enable output, so i dont have 3.3V, only 0,7V.
DVDD 3.3v is logic supply, so i dont get how CPU gets logic levels from ICs when there is no Logic Supply...
When i measure the power for audio amplifier TAS5602DCAR it should be 13V i suppose, but it gets 17.4V, from the CON1300 pins 4 and 5. It is ok for that IC, it works on voltages until 30V, but I worry if that does not affect some other processes.
Fault signal from audio amp is on PIN19 and it is 3.3V that is HIGH and it suggests Normal Operation.
On sound system IC CXA3785R-T6 pin44 the VFAULT signal is LOW 0.7V, that is too normal operation.
But on audio amp pin18 RESER is held in LOW and it does not go to HIGH to get out of the reset mode. That pin is controlled by main CPU signal X_SP_Mute.
On sound system IC CXA3785R-T6 pin43 X_Protect output is LOW 0.4V that means ERROR.
In datasheet it says X_PROTECTOUT outputs “L” when input voltage (SPxP/N) become under 3.0V.
That is on pins 61-62 and 63-64, and if I understand right it needs to have 3+ V DC to output High Normal signal?
Isnt that a bit too high to have on speakers? I measure 0V DC there, and 25mV AC.
What do you think can be the main problem and solution for this ?
I exclude replacing whole board
This is the board picture, service manual and datasheets for ICs
https://cdn.badcaps-static.com/pdfs/...4ea5bf553a.pdf
Attached Files
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