Re: LG 32LC7D no sound
Sorry can't read the IC's but have squared 5 out for you to check for Tom66's suggestion. RU3037...
mikoz
A Tinkerer
Last Activity: 08-06-2016, 03:01 PM
Joined: 12-06-2011
Location: Earlwood NSW
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Re: Acer AT4220 - colour/contrast problem
Ive been through the service manual, which has no schematics (attached). I'm about to recap the main board with quality pan fc's to see if that might help? Just in case it is an esr issue. Just a bugger of a board 55.M34V7.002 to locate in the right revision/configuration at a good price. This one has 2 x HDMI.
Could a VR cause this kind of issue on a mainboard?...Leave a comment:
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Re: Acer AT4220 - colour/contrast problem
Thanks Mrx3750, I'm getting a picture, just a washed out contrasty bright one. I did think that it may have been a firmware issue, alas there is no service or USB port on this one. All menu items appear to work correctly, I do not have the remote for this one though and so cannot try key combinations to access a service menu yet. Waiting for one to turn up on ebay atm.
One thing more that I have noticed this morning is that if I leave the menu up on the screen > 5 minutes without change, after switching it to standby and back on...Leave a comment:
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Re: Acer AT4220 - colour/contrast problem
So far I have tried reseating all cables. Will try hitting the main board with a hairdryer and/or freeze spray over the next few days to try and isolate the failing component.
Have ordered all panasonic FC caps for the mainboard and am awaiting delivery of them.
How do I test the main transformer that is buzzing? Should I re-flow its solder joints, as they look rather dodgy?Leave a comment:
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Re: Acer AT4220 - colour/contrast problem
BumpLeave a comment:
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Re: Acer AT4220 - colour/contrast problem
More pictures......Leave a comment:
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Re: Megmeet MLT666 R2.8 cockroach short
We have a power switch on the wall. Lead plugged into TV with wall switched on fuse blows, I had not touched the TV switch yet.Leave a comment:
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Acer AT4220 - colour/contrast problem
Hi again,
Won this 42" LCD TV on eBay for $52, that was advertised as an Acer plasma with brightness problem. I picked it up yesterday.
I'm concerned after getting it home and apart that it may have a panel issue?
The power board is a Delta dps-291ap, see this post.. [url]https://www.badcaps.net/forum/showthread.php?t=27793&highlight=delta[/url]
Its a well built power supply with Nichicon caps throughout none look compomised. But the primary transformer buzzes pretty loud (is that normal?) The PFC is a 270uf 450V nichicon (I didn't check the... -
Re: Megmeet MLT666 R2.8 cockroach short
Hi Caleb,
Would I just solder a 100w bulb directly to the board? And Freeze spray? (Any particular brand) Does that increase resistance on the problem component and flicker the bulb or something? Could you please provide me some instructions as I've never heard of that method before?
MickLeave a comment:
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Re: Megmeet MLT666 R2.8 cockroach short
OK I'm done.. I give up.. Fuse blows as soon as its switched on at the wall... Tossing it after harvest. All replaced parts still test good but there is obviously still a short someplace.Leave a comment:
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Re: Megmeet MLT666 R2.8 cockroach short
Yeah the green one was marked R20 on the donor board. I've soldered it and the replacement 6N60C mosfets in now to R74, Q8 & Q9 and will report back after I plug the TV in.. if all is well?
Wish me luck..Leave a comment:
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Re: Megmeet MLT666 R2.8 cockroach short
I'm onto the last piece of this puzzle now. Does anybody know what the pink casing denotes as this 0.5R resistor is open. Is this a fusible resistor?
I have salvaged a green one with the first four band colours the same but it has a fifth black band? It measures 0.8R?
This is R74 on this PSU. Would it hurt to try it out?
Picture below......Leave a comment:
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Re: Bush 32TV016HD issues
Hi keithf2,
Could I ask a favor of you to verify the codes on your photo of the two smd's I have circled? I think I have ordered the wrong parts? Ive ordered 2R20 going by the schematic, but in your image it appears to only have 3 digits?...Leave a comment:
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Re: Bush 32TV016HD issues
You probably need to install Adobe Acrobat Reader to view PDF files. I uploaded those files a few days ago to troubleshoot my MLT666B 2.8. In my case I have isolated my issue to Q9 a 6N60C mosfet that is shorted and blows F1. I also have to replace R43 & R44 on the solder side. I have replaced all caps on the board Primary & Secondary with Panasonic FC series, and am waiting for my mosfets to come from element14 (I will be replacing all three on the primary side)Leave a comment:
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Re: Megmeet MLT666 R2.8 cockroach short
pulled Q8 And Q9 out and here is the results.
Q8 Black 1-2=1823 2-3=553 1-3=001
Q8 Red 1-2=553 2-3=1818 1-3=001
Q9 Black 1-2=001 2-3=001 1-3=001
Q9 Red 1-2=001 2-3=001 1-3=001
So I guess Q9 is dead short then.
Is there anything I should test while these are out?Leave a comment:
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Re: Megmeet MLT666 R2.8 cockroach short
FQPF6N60C's are end of life apparently? Could somebody recommend a suitable alternative for me?
I have just had a look on rsonline and they say similar is the FDPF5N60NZ but the continuous drain current is 4.5A instead of 5.5A of the 6n60C is that going to be a problem?
Ive attached datasheets for 5n60, 6n60 and 7n60 below....Leave a comment:
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Re: Megmeet MLT666 R2.8 cockroach short
Primary Top side mosfet test results:
Q14 Black 1-2=1 2-3=564 1-3=715
Q14 Red 1-2=1 2-3=1 1-3=1
Q2 Black 1-2=1 2-3=518 1-3=668
Q2 Red 1-2=1 2-3=1 1-3=1
Q3 Black 1-2=707 2-3=1 1-3=1
Q3 Red 1-2=1188 2-3=703 1-3=1013
Q8 Black 1-2=011 2-3=002 1-3=001 shorted?
Q8 Red 1-2=002 2-3=002 1-3=001 shorted?
Q9 Black 1-2=001 2-3=001 1-3=001 shorted?
Q9 Red 1-2=001 2-3=000 1-3=001 shorted?
Primary Solder side mosfet test results
Q12 1-2=1 2-3=1 1-3=595...Leave a comment:
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Re: Megmeet MLT666 R2.8 cockroach short
Is there a test for the mosfets I can do in circuit seeing as though i have shorted zeners, or do they need to be loose?Leave a comment:
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Re: Megmeet MLT666 R2.8 cockroach short
Yeah it's pretty cheap.
What's the L designation though? It looks like a diode.Leave a comment:
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Re: Megmeet MLT666 R2.8 cockroach short
Bridge red on 1
1-2=1 1-3=1 1-4=1 2-3=559 2-4=0 3-4=1
bridge black on 1
1-2=514 1-3=568 1-4=514 2-3=1 2-4=0 3-4=559
I hope that's ok?Leave a comment:
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