Re: Sanyo DP42849 Backlight Shutsdown
That would be my guess...
Not sure what else you checked or your exact symptoms
KJINTF
Member
Last Activity: 01-02-2021, 09:00 AM
Joined: 12-12-2011
Location: Alaska
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Re: Sanyo DP42849 Backlight Shutsdown
Hi guys
I measured a known good transformer
Good measurements
Pins 5 <> 10 - 114 OHms
Pins 9 <> 6 - 66 Ohms
My defective transformer had the following measurements
Pins 5 <> 10 - 399 Ohms
Pins 9 <> 6 - 66 Ohms
New part works greatLeave a comment:
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Re: Sanyo DP42849 Backlight Shutsdown
Not sure what just happened - posted a response and it's not there
selldoor,
That's a great idea - Thanks for thinking of it - Good to see others are helpful
Will do when I get the new part - should be by march 10th or thereaboutsLeave a comment:
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Re: Sanyo DP42849 Backlight Shutsdown
tom66
Thanks for the suggestion on a ringer
Just talked to the customer - he wants to buy a new board
Bought one off EBay where they want the core back
Looks like I will not be attempting a rebuild on the transformer afterall
I was looking forward to it - O well there will be another in the near futureLeave a comment:
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Re: Sanyo DP42849 Backlight Shutsdown
Hi again
No (ringer) I sure wish I did - always some missing test equipment even after over $20k or more into the stuff
Got any suggestions on how I can kludge one together????????????Leave a comment:
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Re: Sanyo DP42849 Backlight Shutsdown
budm
Thanks for the suggestions
I checked the caps by the transformer - no signs of failure
Additionally as stated earlier I substituted the lamps with an external lamp
Check my earlier post on the secondary winding resistance
Waiting on approval from the customer before I attempt the transformer rebuild
I have had about 70% success rate rebuilding transformers - most of the time the transformers that have internal thermal protection / fuses and a few times with shorted coilsLeave a comment:
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Re: Sanyo DP42849 Backlight Shutsdown
I just started the second option - "Rewind the transformer"
Will keep you postedLeave a comment:
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Re: Sanyo DP42849 Backlight Shutsdown
selldoor,
To answer your question
YES - the transformer secondary winding connects directly to the lamps via long cables. Mine has CN4 (pin 10 of transformer) and CN5 (pin #5 of the transformer) connecting
I removed the connectors and placed a know good lamp on the output - No change after 2 seconds or so a very short duration flash of the lamp - nothing more. Additionally mine has some clear indication of excessive heat under the transformer secondary windings - IMO it looks like a very poor design for...Leave a comment:
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Yes another Sanyo DP42849 Backlight
After looking over the several other Sanyo DP42840 threads
I was not able to find any resolution to the backlight issue
My Sanyo backlight flashes for less than one second after the turn on process
As far as I can tell all the other functions work OK - Audio and video seem to be fine - Just no backlight
To date I removed the CCFL connections inserted a new good lamp with exactly the same symptoms, All voltages BLon, Stby 5v, 12v, etc mesure fine
Have others found that the single inverter transformer itself is the problem?
None... -
Re: Sanyo DP42849 Backlight Shutsdown
Have you made any progress on the inverter transformer issue?
Power / Inverter board data - DPS-260LP A, P/N 1AV4U20C41500
I have the exact same board with a bit different symptom
Upon power on after afew seconds the backlights flash for less than one second
Looks as if the rest of the TV is functioning OK with Video and audio
Pin 9 to 10 measure 370 Ohms
Pin 5 to 6 27 OhmsLeave a comment:
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Re: Samsung BN44-00261B power/inverter board
Thought you might like the schematic
The FETS in question are on page 2 top center position IDs Q1803 and Q1804...Leave a comment:
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Re: Samsung BN44-00261B power/inverter board
Thanks
I did check the diodes - all good
Noticed not much heat sink compound was used on the FETS.
Ordered 10 of the FETS and will hope for the bestLast edited by KJINTF; 11-27-2012, 09:10 AM.Leave a comment:
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Samsung BN44-00261B power/inverter board
I have a Samsung LN32B650 LCD TV with the above power board. Came in with no picture sound OK. Picked up a schematic of the board and found the secondary fuse which supplies power to the inverter MOSFETS open, additionally both FDPF5N50UT inverter FETS shorted. The transformers look fine with no signs of heat issues plus all the small caps across the HV look OK.
My questions
Have any of you seen this problem before?
Is there a reason why the FETS would die?
Should I be looking for more defective components downstream of the FETS?
Thanks... -
Sylvania 6842PE ED Video Monitor
Help - Please
Picked up the above for free, found a service manual, replaced a few defective caps and all is almost well
No way to make any adjustment
The set doesn't have any integrated configuration buttons, only Volume and input source selection buttons. What's with that?
Anyone have a "NE801UD" remote control they are willing to sell me?
Tried several universal remotes programmed them for the set
Was able to get to the setup screen but was not able to activate the controls
Any ideas as to how I might get... -
Re: Vizio VW37 Power Supply PSON working but no 12v or 24v output
OK will do,
Hope this is of some help to others
Additionally have several dozen more manuals
Regards
KJINTF
PS - Check out the differences between the two posted manuals - One is missing several chapters, skips from section 3 > 9...Last edited by KJINTF; 12-19-2011, 08:29 AM. Reason: Saw above post - check the difference between the two manualsLeave a comment:
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Re: Vizio VW37 Power Supply PSON working but no 12v or 24v output
Tetranitrate
Not sure if you have the factory service manual or not - if not PM me and I will send it your way. It's about 2 megs so should easily go through email. There are several dozen detalied block diagrams covering the issues you are experiencing.
As others have stated U33 is a common failure - not sure if it is related to your failure but worth a check. I have had two of theses Vizio's both with U33 problems and a few bad caps but U33 was the primary cause. 1117 chips are cheap and...Leave a comment:
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Re: How Much are You Guys Paying for Broken TVs?
Good Guess - It is!
Including the professional CRT video monitors I would say 35 or so TV/Video monitors hooked up and operational. A GVG Horizon Audio/Video routing system uses somewhere around 15 Sony NTSC HR professional monitors as dedicated destination monitors and 20 plus cameras as inputs. Used to check on what the dogs are barking at and what's happening in the outbuildings. The Barn has a 37" HD Vizio, The garage has a 42" Sylvania, The game room a 37" LG, each of the four bedrooms have their...Last edited by KJINTF; 12-18-2011, 09:18 AM.Leave a comment:
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Re: How Much are You Guys Paying for Broken TVs?
I guess everyone's local market is a bit different
Been lucky here picked up several LG, Vizio, Sanyo and Toshiba LCD's for no more than $5.00 each. The only problem child has been the Toshiba. Agree if someone else tried to fix the set before the risk goes way up
So far more luck with repairing "junk" sets than my My Panasonic tunerLeave a comment:
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Re: Panasonic TH-42PX25
Yes - thanks for the suggestion
There are several choices for both antenna A and antenna B went through them all
Left it on Antenna Only / Antenna A / analog and digital reception
Same result as aboveLeave a comment:
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Re: Vizio VT420M - No picture/No sound
You say the Vizio logo lights up as in changes state when turned on
Nothing else works?
I've seen that symptom on at least three or four Vizio repairs during the past several months
Typically it's been a SMD three terminal 3.3Vdc regulator on the board - <$3.00 for the part
Might want to look at the many AMC1117 regulatorsLeave a comment:
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