Re: PDP-4304 solid red/green LEDs
More info: If I flip the switch beside the Power Supply board, the TV powers up and does not shut off. But when the switch is off, that means some circuits are not activated.
But when the switch is in the normal position, TV shuts off after turning on, then I get the twice flashing front red LED, and the red LED on the power supply board is lit.
brainiac88
Member
Last Activity: 08-01-2014, 11:11 PM
Joined: 06-24-2014
Location: Portland, OR
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Re: PDP-4304 solid red/green LEDs
Replacement power board installed, but a used item from eBay. This one is also defective - twice flashing red LED.
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Re: PDP-4304 solid red/green LEDs
More progress:
I read the Service Manual on Scribd and it mentioned the switch on the board beside the power supply. So I switched it to the UP position, and performed the procedure above, several times, changing the switch position, power-cycling in between, and trying 3,4, and 5 presses of the Muting button. After 20 minutes of trying, I finally cleared the trap indicator - only the red LED was lit. Yes, I taped down the trap switch.
So turning on the TV results in it shutting off after 5-10 seconds, and getting a twice-flashing...Leave a comment:
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Re: PDP-4304 solid red/green LEDs
PROGRESS!!!
Okay so this is what I did:
0. With new AA batteries, point the remote at the lower right corner of the TV
1. Press the “display” button for 1 second, then release the “display” button
2. Wait between 7 and 9 seconds
3. Press and release the “<”, “^”, “<”, “>”, and “power” buttons in sequence
I head a click-click, then a faint buzz sound increasing in amplitude but still no picture or any illumination on screen.... then click. No more...Leave a comment:
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Re: PDP-4304 solid red/green LEDs
I tried very patiently, multiple times, following the one-second cadence, without success. Where is the IR sensor on the TV anyway?
But I'm afraid the power supply I replaced isn't the damaged component. I don't know what to do next...Leave a comment:
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Re: PDP-4304 solid red/green LEDs
I carefully followed the procedure, and nothing happened. The TV did not turn on as stated in step 3 (after pressing “<”, “^”, “<”, “>”, and “power” buttons in sequence.)
Any other ideas?Leave a comment:
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Re: PDP-4304 solid red/green LEDs
No blinking, just aolid red and solid green front LEDs...Leave a comment:
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Re: PDP-4304 solid red/green LEDs
Bump..
Anyone?
Help, please?Leave a comment:
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PDP-4304 solid red/green LEDs
Hi all,
I have a Pioneer PDP-4304. It refused to turn on, so I did some initial troubleshooting a few months ago, and decided to replace the power supply. I installed the new power supply but did not know about this diabolical trap switch. So I turned it on and of course, it did not power up. Instead, I have solid red and green LEDs on the front. I also research as best I could on how to reset this trap switch through the remote, but that did not work either. Couple possibilities:
1 - Something else was broken, not the power supply
2 - The trap switch reset method... -
Re: Philips 42PFL7422D/37 backlight shuts off in 2 seconds
Right, I thought of that too. However, the new inverters were of a different design - see phot. Cost was under US$40 shipped....Leave a comment:
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Re: Philips 42PFL7422D/37 backlight shuts off in 2 seconds
So because no one replied, I ordered replacement inverters off of eBay. I installed them last night and they work perfectly. Hopefully, they last.
Lesson here is that if the backlight goes off after 1-2 seconds, AND if the CCFL tubes do not have black spots or bands, the inverters are bad. So either replace them both, or try to do component-level troubleshooting.Leave a comment:
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Re: Philips 42PFL7422D/37 backlight shuts off in 2 seconds
Hi guys,
Sorry, been out on vacation.
Anyhow, here's what I've got for the tests on the inverter transformers. MTs are the ones on the Master board, and STs are the ones on the Slave board. See photo......Leave a comment:
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Re: Philips 42PFL7422D/37 backlight shuts off in 2 seconds
How do I test "BL-on command" ?Leave a comment:
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Re: Philips 42PFL7422D/37 backlight shuts off in 2 seconds
Okay here's what I've got so far:
- All 8 MOSFETs on both boards tested with ~8.5k across the two legs
- Tested DC resistance between transformer legs. See pic. All pairs (A-B, C-D, pairs on other side of transformer also) tested with zero ohms on both transformers of both boards EXCEPT for C-D on the Master board. Both transformers on the Master board between terminals C-D measured about 750k ohms.
Any tests I can do with a CFL bulb or a laptop CCFL tube?...Leave a comment:
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Re: Philips 42PFL7422D/37 backlight shuts off in 2 seconds
Both fuses tested okay. Fractions of an ohm.
What shall I test next?Leave a comment:
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Re: Philips 42PFL7422D/37 backlight shuts off in 2 seconds
By the way *selldoor*, is the blue LED on the Master inverter supposed to be on when working properly? Or is it a fault indicator?Leave a comment:
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Re: Philips 42PFL7422D/37 backlight shuts off in 2 seconds
Thanks for the correction.
No, I have not tested those. Will do when I get home. I assumed they would be okay because the bulbs did fire up for about 2 seconds.Leave a comment:
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Re: Philips 42PFL7422D/37 backlight shuts off in 2 seconds
I do not have a spare working CCFL tube of the same size. Can I use a smaller CCFL from a laptop panel?
And yes, I do have working CFL bulbs, from 4W up to 23W.
Images:...Last edited by brainiac88; 06-25-2014, 02:05 PM.Leave a comment:
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Philips 42PFL7422D/37 backlight shuts off in 2 seconds
Hi all,
Noob to the forum. I've read dozens of threads on this unit and looking for some advice on repairing my TV. I've taken the entire TV apart, down to separating the LCD from the backlight.
System Info:
-LC420WU5
-Master Inverter: 6632L-0470A PNEL-T707A REV-1.2
-Slave Inverter: 6632L-0471A PNEL-T708A REV-1.2
Symptoms:
- Backlight goes off ~2 seconds after powering on
Observations:
- Blue LED on Master Inverter lights up when powering on, then fades to off, just as the backlight shuts off.
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Re: New Members - please post your introductions here
Noob here. Electrical Engineer but I work in marketing. I fix broken things in my spare time. I find it a challenge and rewarding. I fix mostly electronics and vehicles, but also the occasional fridge and washing machine as the need arises.
Looking to fix an LCD TV and a Plasma now. Will contribute any way I can in the future.
cheersLeave a comment:
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