Re: 42' plasma TV - Denver KTV-55 - Faulty power supply
Hi,
Just a little feedback, it may help someone ;-)
The TV is working fine for one month now.
I just replaced the the 4 pin regulator (the fourth pin was a on/off feature) with a common 3 pin regulator (I had to bend pin 2 and 3 for the pinout match the pcb one ). Before doing this, i checked how on/off feature was controlled and realized that it was directly connected to power trought resistors (no ICs), wich meaned that its state was always to on.
I assume that some manufacturers buy end of...
Djihatch
Member
Last Activity: 09-15-2013, 12:56 PM
Joined: 03-28-2011
Location: FRANCE - Western Europe
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Re: 42' plasma TV - Denver KTV-55 - Faulty power supply
thanks for the tips to both of you.Leave a comment:
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Re: 42' plasma TV - Denver KTV-55 - Faulty power supply
Thanks PCBONEZ, but this component is not available :-(Leave a comment:
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Re: 42' plasma TV - Denver KTV-55 - Faulty power supply
Thanks Plainbill,
I added location in my profile ;-), unfortunately, I live in France, so shipping will be increased for me.
How did you do to find an equivalent ? I searched for hours and no way...
At least, you suggested me and equivalent. I hope that it will be easier to find even in France.
As I'm curious, I used a 3 pin equivalent voltage regulator, and it worked for 20 minutes (it could work longer, but now that I'm sure that this voltage regulator is the only faulty component, there's...Leave a comment:
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Re: 42' plasma TV - Denver KTV-55 - Faulty power supply
Hi,
I've built a test circuit for the voltage regulator... And it has exploded !!! I have to find a new one (I found some of these in china but they cost 20 $ + 15 $ shipping !!!).
Let me know if you have cheaper solution...
Thanks.Leave a comment:
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Re: 42' plasma TV - Denver KTV-55 - Faulty power supply
thanks,
I've built the test circuit but I have no regulated supply at home. I'll grab one at work tomorow and let you know.
Have a nice day (or good night ;-)Leave a comment:
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Re: 42' plasma TV - Denver KTV-55 - Faulty power supply
I get 20.3 V on Vin pin. Unfortunately, I don't have the schematics of this PSU, so I don't know if it's correct. I assume that if it's more than 15v, it should be regulated.
ThanksLeave a comment:
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Re: 42' plasma TV - Denver KTV-55 - Faulty power supply
I used a 250 ohm 1 W resistor between Gnd and Vout. I've measured 11.3 v instead of 15. with this resistor, I should have 6 mA at 15 V (Vout). I'm just above load regulation that is written in the datasheet (5 mA to 1 A) so it should work.
2 options : the regulator is bad or Vin supply is bad and doesn't support load. I'd like to put a dummy resistor between Vin and ground but as I have no schematics, and I don't want to burn something.
++Leave a comment:
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Re: 42' plasma TV - Denver KTV-55 - Faulty power supply
Thanks to both of you.
In fact, the voltage regulator is out of the PCB (for the measurement to be easyer), but the wiring is still the same. I assume that the design of this board is good (with corrects capacitors), so the Vout should be correct too...
for the test, what kind of capacitor should I use ? how should I solder them ? (first between ground and Vin, second between ground and Vout ? 1 unpolarized cap between Vin and Vout ?)
Thanks againLeave a comment:
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Re: 42' plasma TV - Denver KTV-55 - Faulty power supply
Thanks Plainbill
I unsoldered the voltage regulator an put it on a PCB like (I don't know how its called in english : The blank ones used in labs where you can put components and wires without soldering).
So I was free to perform all tests. I can't check the temperature because power is on during 1 second then the relays turn it off. So there is not enough time for this component to heat.
Here are the results, during the second when the power is on :
pin 1 (Vin - Dc input) : 20.3 V - 38 mA...Leave a comment:
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Re: 42' plasma TV - Denver KTV-55 - Faulty power supply
Thanks a lot. this website seems to be very interesting.
I found a KIA78R15PI (voltage regulator) that gives me 10 V (Vout controled with a scopemeter) instead of 15 V, wich may explain that the NCP1653 controler doesn't drive correctly the FETs.
Does that means that the voltage regulator is bad ? (That sounds weird to me, I thought that a bad voltage regulator should give the same voltage as Vin if shorted, or nothing is open but not another regulated voltage)
Does that mean that it is overloaded...Leave a comment:
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42' plasma TV - Denver KTV-55 - Faulty power supply
Hi, I'm back with another problem ;-) I hope that someone will help...
I bought 5 TVs from a guy who thought that they were LCDs (I know a bit more about LCDs). When I was in front of the TV's, they were obviously plasma TVs. They were cheap and my aim is to learn, so I bought them. But now I need your help to fix them !
The PSU is a Samsung one : LJ44-00133 A (I seached a lot and can't find the schematics, if someone can help ;-) ).
The problem :
When I plug the plasma, the led panel is red (which seems to be ok)
When I turn on the plasma... -
Re: dell E173Fpf burnt parts
Thank you !
In fact I like to read every post even when this is not about a monitor/TV that I own. That's why I don't need to post everytime ( Don't worry, a 37 and 40 inches flat TV with video problems wait for me, and I will probably need your help !).
Just a little feedback for noobs like me :
For the 1st TV (Samsung 32') : That was a specialised IC (F9222L) that was faulty.
For the 2nd TV (LG 32') : Obvious bad caps. 10 minutes to fix this one !
For the 20 monitors :
...Leave a comment:
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Re: dell E173Fpf burnt parts
Hi,
Thanks to all of us who gave me advices about my problem.
I gave up with this monitor... My local dealer couldn't get some parts, and shipping was too expensive from other dealers.
But I didn't waste your time : from this first experience, and by reading this forum, I fixed more than 20 LCD monitors for my school, and 2 32 inches tv (for me ;-) ).
So thanks again to all of us. I hope that one day I'll get enough experienced to help other people.
Hope to see you soon !
...Leave a comment:
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Re: dell E173Fpf burnt parts
Thanks a lot.
I'll follow your advices and let you know.
Have a nice day.Leave a comment:
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dell E173Fpf burnt parts
Hi,
Thanks by advance for those who will help me ;-)
I've got a non working Dell E173Fpf and I would try to fix it.
Q850 is shorted and I have to replace it. My problem is that I can't read R856, C856 and R861 values anymore (see pictures)...
I already searched on previous posts, but values that are given by forum members are not the same from a topic to another, and noone seems to be aware of C856 value...
I searched for E173Fpf service manual, but no way.... Only E173Fp service manual is available.
Anyone can help ? ;-)
...
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