lkvee
Senior Member
Last Activity: 09-16-2020, 06:43 PM
Joined: 02-25-2009
Location: New Jersey
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Monoprice Hybrid Amp 13194 may need caps
User reports humming which starts immediately after powering up. That leads me to focus on the solid state parts. The capacitors are by Chong and don't look popped. Not sure where else I should focus to pinpoint root cause.... -
Re: Samsung LN52A650A1FXZA T-Con board issues?
Focusing on the mainboard now with more pictures. Model number reads BN41-00972C and there are parts with the designation "DEx AS7". I don't know their exact specs.
I found C131 but I can't find C102
Would love to apply heat but not sure where to target
Will also consider replacing certain parts but don't know exact specs, yet.
Thanks for reading... -
Re: Samsung LN52A650A1FXZA T-Con board issues?
Try this one!...Leave a comment:
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Samsung LN52A650A1FXZA T-Con board issues?
Loops with the startup sound and a bad image.
[url]https://www.youtube.com/watch?v=dTLTGaJhxQ0[/url]
We changed the behavior by disconnecting the cable from the T-Con board. Played startup sound and no image but relay didn't click.
Also noticed a little bit of a viscous fluid on the chips. No other apparent liquid damage on the other boards. Caps on power board are not bulged and some use 820uF. All are by SamYoung.
Will likely get a replacement T-Con board.
What happened to the (apparently bad) T-Con board?Loops with... -
Re: Vizio E420-A0 fails to sustain power
Got a strip of new resistors. Desoldered one and tested it out of circuit.
I got 1 MOhm.
I resoldered the same resistor back in circuit and got the original ~667 Ohm reading.
Not sure what to examine this timeLeave a comment:
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Re: No backlight on Sharp LC-32LB261U
Just acquired the service manual from Elektro Tanya. It's the same manual for the next two larger size TV's, too.
There's a decision flowchart, and one of the decision diamonds ask whether I am getting 12V AND 19.5V from the power board. If not, replace it.
I see the 19.5V at C9100 but nowhere else. I can say with confidence I never got 19.5V on any pin during any state.
My schematic literacy is barely >0 but I can't read which pin's supposed to generate 19.5VLeave a comment:
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Re: No backlight on Sharp LC-32LB261U
TV changed behavior. LED cycles with two RED blinks, but fails to turn blue. Using the remote fails to turn it on, too. Eventually, that blinking red LED goes steady but I still can't turn it on.
I do remember being less than careful enough with the needle probe on CN9101. I saw a blue spark on three occasions.
Here's what I found for CN9101 on the outer pins:
NC 0V
+12V cycles between 12.5V and 0V
+12V cycles between 12.5V and 0V
+12VAU steady at 12.4V
GND 0V
GND 0V...Leave a comment:
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Re: No backlight on Sharp LC-32LB261U
Black lead was on the metal chassis. Red one was on one of the two VLED+ pins. I plugged in the TV and observed voltage.
Immediately went to 12.39V and then went to "OL" (around the fourth out of eight red LED blinks), then to a range of 36-37 volts and back to 12.39V
I'm using a Fluke meter with autorange.
Not sure if what I saw was a consistent "surge".
Both VLED+ pins behaved this way.Leave a comment:
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Re: Vizio E420-A0 fails to sustain power
This is encouraging news. Can't exactly tell whether R133a, b, and c, are 1206 or another size. I wanted to measure with digital calipers, but I noticed red ... adhesive? ... obstructing the calipers.
If I'm reading the last post correctly, the recommended course of action is to replace all three resistors. Replacing only one or two is not recommended....Leave a comment:
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Re: No backlight on Sharp LC-32LB261U
Can't find the button/link to edit my original post, but the original post was for Pins 15 to 1 in descending order.
For Pins 16 to 2, I got these readings during standby (steady red LED):
NC 0.23V
+12V 12.6V
+12V 12.6V
+12VAU 12.48V
GND 0V
GND 0V
NC 0.16V
DIM ON/OFF 0.14V
For Pins 16 to 2, I got these readings during ON state (steady blue LED):
NC 0.23V
+12V 12.59V
+12V 12.59V
+12VAU 12.34V
GND 0V
GND...Leave a comment:
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No backlight on Sharp LC-32LB261U
Red LED blinks 8 times before turning steady blue, but I see the "No Signal" image without backlighting.
At CN9101, I get these readings on steady red LED (standby):
NC gives 0 volts
+12V gives 12.59V
+12V gives 12.59V
+12VAU gives 12.47V
GND gives 0V
GND gives 0V
NC gives 0.057V
DIM ON/OFF gives 0V
At CN9101, I get these readings on steady blue LED (ON):
NC gives 0V
+12V gives 12.58V
+12V gives 12.58V
+12VAU gives 12.33V
GND gives 0V
GND gives... -
Bad Fimware on Vizio E422VA?
TV perpetually power cycles with a backlit Vizio logo. Looks like it keeps failing a power-on-self-test. Been reading about a possibly bad EEPROM, but the one thing I have yet to try is to plug in the TV via WIRED Ethernet.
Supposedly, the TV will download the most recent firmware and self-update.
Has this worked based on your experiences?
I can't find scorching, heat, or burning on the "offending" EEPROM on the video board.... -
Re: Vizio E420-A0 fails to sustain power
Best I could do was check resistance for R133a, b, & c, as well as resistance between pins on IC120. Given my eyesight at the time, I couldn't find anything officially indicating Pin 1 (like a notch or a recessed hole). For this post, I am designating the lower left-hand pin as Pin 1 and the lower right-hand pin as Pin 5 if you're facing IC120 with R128 on your left and C125 on your right.
I tested while the power board didn't not get power, because I had to disconnect the power between the board and the...Leave a comment:
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Re: Vizio E420-A0 fails to sustain power
TV's not accessible ATM, buuuuuut, my experience with the meter's a bit limited. When I test IC120, am I looking for continuity, current, orrrr ... capacitance?
Will get specs on the main capacitor (voltage and capacitance specs are obstructed by placement and glue).
Would this entire thread change direction if I got the same voltages from the original board? The readings up above were from a replacement board from eBay. Willing to consider the idea that both boards are bad.Leave a comment:
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Re: Vizio E420-A0 fails to sustain power
I unplugged the TV.
I shorted the leads.
I put alligator clips on the leads and measured DC voltage.
3V unplugged
166V standby
Yes, 303V power-onLeave a comment:
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Re: Vizio E420-A0 fails to sustain power
Just replaced the power board, but still replicated the original symptoms. Here are the readings for the replacement power board going to the main board.
Here's what I got on Standby:
Pin 12 NC Zero Volts
Pin 11 PWM2 Zero Volts
Pin 10 PWM1 Zero Volts
Pin 09 B/L ON/OFF Zero Volts
Pin 08 REMOTE ON/OFF Zero Volts
Pin 07 12V Zero Volts
Pin 06 12V Zero Volts
Pin 05 GND Zero Volts
Pin 04 GND Zero Volts
Pin 03 GND Zero Volts
Pin 02 +5.2Vsb 5.16V...Leave a comment:
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Vizio E420-A0 fails to sustain power
Acquired the "non-working" TV from someone who got a replacement TV through an extended warranty.
TV will shutdown eventually on its own - longest "session" was less than one minute. In some instances, the TV never generates a backlighted Vizio logo and its power LED immediately starts to fade after going full bright white.
I can't replicate the exact behavior with regards to duration of the power-on state. Sometimes the TV fails to turn on. Sometimes its power LED will light and then fade. Other times the TV will behave as expected before generating... -
Re: Sanyo DP26647 - Pls help me diagnose it
Thanks for the feedback. I looked at the pics, and I tested DCV when the TV's plugged in, but the power button was not activated. I also tested after hitting the power button.
I used a flashlight but still wasn't able to find an image. I did see something that looked like the faintest flicker of backlighting, before going back to black.
The pins had these labels:
24V
24V
GND
GND
12V
12V
GND
GND
5V
5V
GND
GND
...Leave a comment:
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Re-assembling Element FLX-3211B for testing
Previous owner went inside the unit and left the cable to the T-Con board disconnected. I wanted to reconnect everything so I can test voltages coming from the power supply board. I am assuming these voltages can only be measured on a fully assembled TV.
Looks like there's some damage to the port on the T-Con board.
I tried and tried and tried, but I could not get the connector seated correctly.
I get the funny feeling previous owner got a replacement T-Con board and found out it won't play nice.
Was really looking forward to testing... -
Sanyo DP26647 - Pls help me diagnose it
Plug it in, hit the power button, and I hear a faint click (relay?), but no LED and no backlighting. Failed to see image.
T4AH/250V fuse is intact.
No voltage of any kind going to the inverter.
Pins 4 and 5 to the video board generate 5.13 V
Pins 8 and 9 to the video board generate 0.167 V
All other pins to the video board show zero.
No caps look bulged. None are from the notoriously bad brands.
Not sure whether to continue looking elsewhere or whether to just replace all caps or do something else....
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