Re: vizio m601d-a3r panel or tcon failure
I scrapped it as a bad panel.
crosstalk
Senior Member
Last Activity: 01-05-2023, 07:21 AM
Joined: 02-25-2014
Location: Pa
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Re: Sharp lc-c32d42u no standby
Thanks for your help. I got it working. Looked more carefully and found R7902D open. Replaced that and 5v standby is back and the tv is working.Leave a comment:
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Re: Sharp lc-c32d42u no standby
Yes those diodes checked out ok. I have 3.53vdc between pins 1 and 3 and 4.24kohms between 5 and 8.Leave a comment:
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Re: Sharp lc-c32d42u no standby
Thanks. I saw that thread too. I checked D7908 and the other diodes near the photocouplers and they were ok. There could be other problems in that area--I'm not too sure how the photocoupler setup on the secondary side is supposed to work to feedback to the smps IC.Leave a comment:
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Sharp lc-c32d42u no standby
Hi. I have no standby on this power supply in a sharp lc-32d42u. I found D7907 (1N5383B) shorted, so I replaced that and IC7905 (TNY268PN). I have 160vdc on the drain pin of the IC, 0vdc on the source, and 2.2vdc on the EN pin of the IC. I thought maybe the first replacement IC was a bad part, but trying a second one didn't help--still 0v on the 5vdc standby output.
What else should I be checking?...Last edited by crosstalk; 03-07-2017, 01:43 PM. -
Re: Sharp LC-50UB30U backlight drive current
Yes, those are the board and strings. There are two strings and two drive circuits. The working voltage for c304 and c404 is 250V. I am getting 500mA of current in each string. The drive voltages are 117.16vdc with return of 26.569vdc and 117.16vdc with return of 25.857vdc.
A magnified photo of one of the original LEDs is attached....Leave a comment:
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Re: Sharp LC-50UB30U backlight drive current
The original LEDs are 3v. There are 32 on each string (2 total strings). When I tried to replace all of them with the 350ma replacements, the led driver would shut down right away. I added a few of the original ones that were working back and the strings light again with current measured at 500ma.Leave a comment:
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Sharp LC-50UB30U backlight drive current
I have a SHARP tv with an AUO panel. When I got it, the backlight wasn't working. Found lots of bad LEDs. Replaced some with what I had (3v 1w LEDs) and tested. All the strips are working now, but the drive current is about 500mA on both drive circuits. Has anyone seen an LED drive at 500mA--seems quite high and likely to burn out these LEDs. I checked the current sensing resistors and they seem ok. I suspect I need to buy some 1.5w LEDs to do a correct repair. -
Re: vizio m601d-a3r panel or tcon failure
Yes--backlight is uniformly illuminating. I was hoping from the original description of the problem that the "darker on the left" description was a backlight problem.Leave a comment:
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Re: vizio m601d-a3r panel or tcon failure
Thanks again. At least I didn't pay anything for it--I did have to go pick it up though.Leave a comment:
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Re: vizio m601d-a3r panel or tcon failure
Thanks--I was thinking the panel also (gate drivers). I have read the long 70" vizio thread about removing gate drivers on one side. Not sure it applies to this panel, I might pull off the gate driver chip tab on the bottom of the left side just to see what happens.Leave a comment:
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vizio m601d-a3r panel or tcon failure
Hello. I have a vizio m601d-a3r with a sharp panel. Trouble is a few horizontal lines and left side is quite dark. Backlight seems ok. I have tried cleaning/reseating the ribbon cables, but no change. Tab bonds don't seem to affect the picture either.
I am thinking bad panel, but want to get your opinion on whether you have seen this kind of failure with a tcon....Last edited by crosstalk; 05-24-2016, 08:00 AM. -
Re: Sharp LC-60LE633U 2-5 flash
Too bad the connector was damaged, but the pins inside look ok. Maybe the ribbon will still make good contact?Leave a comment:
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Re: Sharp lc-60le810un power supply
Sorry I don't have a schematic for the power supplyLeave a comment:
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Re: Sharp lc-60le810un power supply
Thanks for the help with the power supply and testing. I got this one fixed with a new main board.Leave a comment:
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Re: Sharp LC-60LE633U 2-5 flash
I'm not sure if your lvds ribbon cable has a plastic housing around it. If so, push the cable into the housing so all the contacts are visible and the end of the ribbon is flush with the edge of the plastic housing. It seem like the ribbon isn't making a good connection if you are backing it with foil tape....Leave a comment:
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Re: Sharp lc-60le810un power supply
So I am finally getting back to this TV. After more testing, it looks like the main board is the problem (short on 1.8v power rail). I figured out there is a signal labeled STB that the main board asserts to fully turn on the power supply. After asserting that signal, the power board works fine.
I checked for shorted MLCC bypass caps and didn't find anything. I am now suspecting a bad video processor. Seems unlikely that the bga pads developed a short vs. an internal short in the processor. Any use in trying to heat the processor...Leave a comment:
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Vizio E421VO firmware file needed
Hello. I picked up a Vizio E421VO with corrupt firmware. I found a bin file for a E320VL, which uses a similar main board. The TV is mostly working with this file, but the tuner doesn't find any channels. Could be a bad tuner--could also be wrong firmware for the tuner on the board.
Does anyone out there have a E421VO firmware dump? Seems ridiculous that people sell programmed chips, but the files aren't available. -
Re: Sharp lc-60le810un power supply
Thanks. That would be great. I didn't see a power supply schematic in the service manual I have.Leave a comment:
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Re: Sharp lc-60le810un power supply
I removed Q7923 from the board and it tests ok. Does anybody have a schematic for this dps-219 board?Leave a comment:
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