Re: JVC LT-40DJ51J - Vestel 17IPS20 - LEDs very dim
Hi ReeceyBurger123,
thanx for Your advice. Did it nearly the same way as You described, but lifted the lcd with the plastic bezel, seemed to be a little more safer for the display. Anyway, after that it was easy to locate the defective lcd, took it out and managed to exchange it with a similar one from a telly with a broken screen. Everything fine now, all led´s lit up. Just waiting for the glue holding this little optical lens now to dry up, then i´ll reassemble the unit again.
Thank you Vestel, you gave my afternoon...
PL519
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Last Activity: 10-10-2023, 02:03 AM
Joined: 07-30-2013
Location: NRW
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Re: JVC LT-40DJ51J - Vestel 17IPS20 - LEDs very dim
yeah, you´re damn right. It was just a "blip" in my old brain and i wanted a quick and dirty realisation.
BTW, can you tell me how to get access to the led-stripes inside the panel? Doesn´t seem to be an easy process without damaging it.
TIA,
WolfLeave a comment:
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Re: JVC LT-40DJ51J - Vestel 17IPS20 - LEDs very dim
Hi,
i´m working on exactly the same chassis, only difference it´s a telefunken brand type D42F182N2, age: 2 years and two month, just out of warranty. Customer told me that screen went totally black from one second to the other. First assumption was backlight LED´s. With the information from ReeceyBurger123 (thanx to him) about the voltages i built this nasty chain of high current led modules from Citizen. They are normally driven by 350mA constant current which leads to a drop-out voltage of abt. 33V. 5 of them in series...Leave a comment:
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Fluke PM6303A RCL meter service manual needed
Hi guys,
can anybody help me with a service manual or even with the schematic of this RLC meter? It´s working but shows curious results when measuring small or big capacitors, inductors or resistances. Any hints or help is pretty much appreciated.
Thanks in advance,
PL519 -
Re: Need advice on some good old HAMEG oscilloscopes!
Hi,
i can really recommend the good old Hamegs. Since my early days in electronics i always worked with them. My first was the HM203, 2x20 Mhz bandwidth, which did a pretty good job for abaut 20 years. One simple problem with defocussing, found a cold solder joint. Second problem was far more dramatical: burnt hv winding of the main transformer. Nevertheless good quality. My actual scope is the HM407 with digital storage. Don´t need that option very often, but sometimes pretty useful when developing with microcontrollers....Leave a comment:
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Re: Philips 42PFL7962D/05 Dead blue LED flashes
Hi Teddibear,
chassis is LC7.5E_LA. Service manual can be downloaded from this site:
[url]http://www.eserviceinfo.com/downloadsm/56687/PHILIPS_LCD%20TV.html[/url]
According to the manual one blink means "DC protection of speakers", three blinks means "Reserved" (for what??
).
Try disconnecting the +- supply voltage of the audio power amp TDA8932T.Re: Philips 42PFL7962D/05 Dead blue ... be downloadedLeave a comment:
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Re: Vizio E320VL Backlight Issues, Inverter board?
Hi,
the missing component labeled C408 seems to be part of the balancer circuit for the ccfl tubes, guess its value is about 15-30pF at 3kV. Take one out of your old board and solder it in place on the new one. It seems to me that C408 is an essential part for detecting bad ccfl´s...?Leave a comment:
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Re: Phillips 42pfl7432 no backlight
Hi,
this is the typical failure with these LG inverters. Did You do the modifications recommended by Philips? Just had this issue and could it solve it with the repair kit containing the BD9897, the TVS diodes, SMD resistors and MosFets....Leave a comment:
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Re: Element ELCHW321 Catastrophic Failure
this is definitely 0.15 ohms / 3 watt and should be replaced by a resistor of the same type. It measures the source current of the mosfet to give a feedback to the pfc controller ic. Don´t forget the bridge rectifier as i mentioned before, replace it even if it measures o.k.Leave a comment:
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Re: Element ELCHW321 Catastrophic Failure
regarding the remnants of a cap on your first picture i think this must have been an electrolytic cap and also regarding the application circuit schematic on page 11 of fairchild´s application note the only elcap there is C6. The bom´s on the next pages list C6 as 22uF/25V for a 100W smps or 47uF/25V for a 200W smps. So if the blown cap is connected from pin 8 FAN7530 to ground this could point to the right dirction. The blown zener diode could be ZD1 in the application circuit schematic. Regarding the bom this a 1N4746, 18volt, 1W zener...Leave a comment:
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Re: Element ELCHW321 Catastrophic Failure
sorry, my fault. Forgot the photo!...Leave a comment:
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Re: Element ELCHW321 Catastrophic Failure
Hi,
FAN7530 is a pfc (power factor controller), that´s the first stage of a smps after the mains rectifier. I´ve marked the rectifier in red, the mosfet is marked in yellow (maybe only the right one, maybe both in parallel). Any shorts?
I see the fuse had a rating of 4amps, so the trip point maybe much higher. This higher current flew through the rectifier and even if you don´t see any shorts or o.c. on that i would suggest to change it anyway. Could you take a photo from the solder side, which covers a bit larger area around...Leave a comment:
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Re: Element ELCHW321 Catastrophic Failure
Hi mmartell,
look at this application note from fairchild, you´ll find good hints to get the values of the components which are totally burnt:
With the mains fuse o.c. i assume the mosfet is gone to heaven too. I would check for a short between drain and source. I would also replace the mains rectifier, even if it is tested o.K..Leave a comment:
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Re: Plasma Y-MAIN board LJ92-01200A
Hi,
pretty good question! I´ve read and learned alot from reading different posts in this excellent forum. I take my hat off to all the plasma and lcd gurus here! Great job and thanks!
I myself have abt 30 years of experience with crt tv´s, now getting familiar with lcd´s, but plasmas are still a book of seven seals to me. This one stood in my garage for abt 3 years, not knowing if it is worth the time to look for. Anyway, with the help of this forum i gave it a try and let´s see what happens.
While you are waiting...Leave a comment:
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Re: Plasma Y-MAIN board LJ92-01200A
Hi,
I cannot answer your latest questions but i have the exactly same issue here with this y-main. Found one IC (U5406) shorted on the upper y-buffer. After unsoldering the IC i connected both buffers and the y-main with the rest and fired up the set (btw: Philips 42PF5331/10 - chassis LC4.41E AA) expecting the tv to show up a -distorted- picture. Screen totally dark with green led on front continously green (no blink). Following the repair tips from freakafter8 i measured R5090/5028 and D5009/5018 with component tester in my scope. All...Leave a comment:
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Re: Hisense lcd40v57ca 120Hz Ripple
Hi,
with 99.9% probability it´s the mains filter cap, since in switching power supplies you only find 60/120Hz on the primary side of the supply. Had the same issue with my satellite receiver, two lines on the screen, sometimes rolling upwards, sometimes downwards. Mains filter cap was totally dried out (not bulged!), no capacity anymore. Replacement should have same or more capacitance, same or higher voltage range, it´s a good idea to take one with higher temp range (105°) for a longer life.
Greetings,
WolfLeave a comment:
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Re: Need information about CCFL's
Hi,
interesting to see that all these AUO displays seem to have the same probs. I was working on a philips LC7.5E-LA chassis with same the display some weeks ago. In the same moment the bulbs were ignited i could hear a "pitch" by a little spark inside of the display which caused the whole tv to reset. After opening the display and isolating the area where the sparks occured the bulbs could be ignited. There were 4 bulbs completely dark, found definitely to be defective by exchanging with a good one. 5 bulbs lighted up totally,...Leave a comment:
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Re: Vizio VO47LFHDTV10A burnt spot on PSU, replace or try to fix?
Hi,
looks good so far, since both inductors are in parallel. Looking at your picture it seems you have changed C241, but not the other filter caps. I would recommend to change C240A und C240B too as they are responsible for the high ripple current through the inductor coils!
Greetings,
WolfLeave a comment:
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Philips 22PFL5403/TCM2.0E LA backlight fixed
Hi,
just fixed this nice little full HD tv/pc-monitor and may be this helps someone else trying to repair the same chassis. Just got this one for small money, no backlight coming up when switching on, sound o.K.. Measured inverter supply, o.k. with 12V and bl_on also switching from 0V to 2,5V. So definitly an inverter issue. After short inspection a 0603 smd-fuse marked "P" was found o.c., replaced by a small wired version with 3A rating (see pic3 upper side in the middle of the pcb). After three days of testing the tv is still running, so it seems that the fuse died of aging.... -
Re: Philips 42inch backlight
Hi,
thanks a lot for the advice. I finally did it your way! Those things are so damn fragile, it really caused me headaches and i was totally sweaty...! Nice experience though!
Thanks again,
PL519Leave a comment:
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