Re: Ocosmo E32 no backlight
TV is fixed. I used a Samsung LM301a 3x3mm LED with a CCT = 6500K. Things I note:
1. The existing LEDs appear to have a higher CCT because the corner of the display where the new LED is placed is a little yellow compared to the rest of the screen. 6500K was the highest CCT that was offered for the LM301a.
2. The intensity of the new LED is a little greater than the existing LEDs which was noticeable on the bench, but not in the TV.
taman
Member
Last Activity: 07-24-2020, 06:49 PM
Joined: 10-11-2016
Location: Rochester NY
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Re: Ocosmo E32 no backlight
I don't see an adjustment for backlight level. How do I adjust the backlight level?Leave a comment:
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Re: Ocosmo E32 no backlight
One interesting note: when I adjust the brightness, the voltage and current on the backlight LEDs stays the same. I would expect the current to decrease.Leave a comment:
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Re: Ocosmo E32 no backlight
Shorting out the defective LED, the backlight drive is 77.7Vdc @ 347ma, driving 20 LEDs. That gives a Vf of 3.885V.
The brightness setting was set to maximum before I disassembled the TV.
The part size I stated earlier should probably be 3.5mm x 2.8mm which is a 3528 metric or 1411 imperial smt size.Leave a comment:
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Re: Ocosmo E32 no backlight
I removed the lense and the LED measures 3.4mm x 2.8mm and is 0.85 mm tall. Picture attached....Leave a comment:
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Re: Ocosmo E32 no backlight
There are 3 LED backlight strips with each strip having 7 LEDs. All of the LEDs are wired in series and one LED on one strip is bad, therefore, no LED flash on power on or ever. The LED strip has the following numbers on it:
SJ32L321-DH-13052201
Y5JC032
IC-B-HWA032D255
Does anyone know what the LED is or if the LED strips are available?
Photos of the control/power supply board and an LED strip are attached....Leave a comment:
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Re: Ocosmo E32 no backlight
The backlight does not flash.Leave a comment:
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Ocosmo E32 no backlight
I have an ocosmo model E32, p/n CE3200-WX2201P7A with a control/power supply board: B13073811-1A03980 HV320WX2-201 rev A1.
Picture and sound are present, but no backlight. On power-up, the backlight voltage goes up to about 125vdc and then quickly drops to 48.5vdc and is steady there. Adjusting the brightness has no effect on the backlight voltage.
Is this proper behavior and voltage for the backlight? -
Re: Samsung LN37A550P3F(XZA) backlight issue
TV did not fail while out of the entertainment center. It is probably a little warmer there.
While I had it out, I replaced the caps on the power supply and backlight driver boards. It is now back in the entertainment center. I expect that it won't fail anymore. Hard failures are much easier to diagnose.Leave a comment:
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Re: Samsung LN37A550P3F(XZA) backlight issue
I have the TV on its face, back removed, cover over backlight power board removed and screws put back in place. The TV has been on for over an hour and does not fail. I have recorded the voltages of all of the connector pins on the power supply board. Waiting for it to fail.Leave a comment:
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Re: Samsung LN37A550P3F(XZA) backlight issue
Inverter board is VIT71037.50 LOGAH REV:1
I'll measure voltages tomorrow evening.Leave a comment:
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Re: Samsung LN37A550P3F(XZA) backlight issue
Board number is BN44-00216ALeave a comment:
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Samsung LN37A550P3F(XZA) backlight issue
Just this morning, the TV went blank - no backlight. If I turn off and on the TV, the backlight is good for about 5 minutes then out again. I haven't taken it apart yet, but I'm guessing a capacitor issue on the Inverter board.
Can anyone point me to a schematic of the inverter board for this model? -
Re: New Members - please post your introductions here
Hi. I'm Tom and have been doing repairs on my own stuff, both electronic an mechanical for over 40 years. I also repair equipment of friends and family. Most of the electronics problems I see are related to electrolytic caps in high voltage power supplies. This forum looks good for the average person that can handle a soldring iron and replace those bad caps, saving a lot of money.Leave a comment:
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