Sharp Aquos LC-32D40U - no image

[ahickman]

I read throught the datasheet and saw the 2.20 VDC +/- 1%, but thought it was dependent upon VCC which in the example was 3.3 VDC. On this board, VCC is 5.3 VDC. Make a difference?

Checking my DVM against a reference voltage source now.

Looked over the various voltage regulators on the PS:

IC506 = 5.01 VDC
IC508 = 5.33 VDC
IC505 = 5.19 VDC
IC510 = 8.90 VDC

[ahickman]

Were it you, would you be confident that the t-con is the defective board?

[retiredcaps]

Originally Posted by ahickman

I read throught the datasheet and saw the 2.20 VDC +/- 1%, but thought it was dependent upon VCC which in the example was 3.3 VDC. On this board, VCC is 5.3 VDC. Make a difference?

My interpretation is that it is a fixed 2.20V regardless of Vcc. Vcc can be 2.5 to 20V (page 4).

Looked over the various voltage regulators on the PS:

IC506 = 5.01 VDC
IC508 = 5.33 VDC
IC505 = 5.19 VDC
IC510 = 8.90 VDC

I'm talking about voltage regulators on the main board (where the AV, HDMI, RCA).

[retiredcaps]

Originally Posted by ahickman

Were it you, would you be confident that the t-con is the defective board?

Not until I check out the voltage regulators on the main board. See above post.

[retiredcaps]

Originally Posted by ahickman

Checking my DVM against a reference voltage source now.

What make and model do you have? Some manufacturer products age better than others.

[ahickman]

Checking main board VR's now. DVM I am using checked out OK. Vref = 3.30V and reads as 3.31 VDC.

IC3804 (3.3 v REG ON AV BOARD) = 3.36 VDC
IC3201 (3.3 V REG on scaler board) = 3.30 VDC
IC3202 (1.5 V REG on scaler board) = 1.60 VDC
IC3602 (3.3 V REG on scaler board) = 0.0 VDC
IC3601 (1.8 V REG on scaler board) = 0.0 VDC

[retiredcaps]

Originally Posted by ahickman

IC3602 (3.3 V REG on scaler board) = 0.0 VDC
IC3601 (1.8 V REG on scaler board) = 0.0 VDC

What is the reading for all pins on the two above?

[retiredcaps]

Originally Posted by ahickman

IC3602 (3.3 V REG on scaler board) = 0.0 VDC
IC3601 (1.8 V REG on scaler board) = 0.0 VDC

What are you calling the scalar board? Post a picture of it with the two ICs above circled in red.

[ahickman]

Pins #2 on both read 5.0 VDC. Remaining pins have 0.0 VDC. Attached are a front/back shot of scaler board.

[retiredcaps]

Originally Posted by ahickman

Pins #2 on both read 5.0 VDC. Remaining pins have 0.0 VDC.

What is part number of both?

[ahickman]

Ic3602 = ba00bc0wfp
ic2601 = bd7820fp

[retiredcaps]

It looks like both belong to a subsection called MICON2. I'm not sure what that stands for, but it is possible that until the TV actually turns on, those output voltages are at 0.0V. It will all depend on what the datasheet says those components are and the expected output voltage.

Are those 2 connectors (CP3601 and CP3603) on MICON2 usb ports?

[ahickman]

They both look to be part of the HDMI interface. Both have pins #1 (Vc) connected to a H_INT line. Might be that they don't turn on until this pin goes high?

[retiredcaps]

Originally Posted by ahickman

Ic3602 = ba00bc0wfp
ic2601 = bd7820fp

1)
http://pdf1.alldatasheet.com/datashe...A00BC0WFP.html

page 2 says for a VCC of 5V, Vo = 3.0V, 3.3V

2)
http://www.rohm.com/eu/fileadmin/med...nformation.pdf

page 1 says output voltage is 1.0V minimum and 5.0V maximum.

3) So if both ICs are supposed to output non zero voltages as per datasheet, then the MICON2 subsection is bad.

4) For both ICs, see if the VCC pin is shorted to ground pin. Any reading under 30 ohms suggests short.

5) If they aren't turned on until a HDMI cable is connected, then it may be working as intended.

[retiredcaps]

If MICON2 works as speculated, then that only leaves the t-con. If you can find a replacement t-con for $20 on ebay, it might be worth shotgunning this one?

I would wait for momaka to see what he thinks of the 5% out of tolerance on U300 first.

[retiredcaps]

Originally Posted by ahickman

Q302 - 8 pin chip, numbers as they appear:

4422
8E5519

See if the mosfet is shorted between Vdd and GND.

http://www.datasheetcatalog.org/data...or/mXsrxsr.pdf

Measure the DC voltage of Vdd, input, and output with respect to GND.

[ahickman]

Neither are shorted to ground.

[ahickman]

Originally Posted by retiredcaps

See if the mosfet is shorted between Vdd and GND.

http://www.datasheetcatalog.org/data...or/mXsrxsr.pdf

Measure the DC voltage of Vdd, input, and output with respect to GND.

Pins 1, 2 and 3 are shorted to ground, but pins 4 and 5 are not. According to the datasheet you linked to, 4 and 5 should be GND?

[retiredcaps]

Originally Posted by ahickman

Pins 1, 2 and 3 are shorted to ground, but pins 4 and 5 are not. According to the datasheet you linked to, 4 and 5 should be GND?

Do you have correct orientation for the pin? The notch tells you where pin 1 is.

[ahickman]

Correct orientation.