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Old 12-06-2018, 02:27 PM   #21
thuss
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Default Re: Panasonic led tv 55ds500

The small one is rated at 44v. Yes I did put black probe chasis.
Still waiting for my led tester............

I will put new photos on later today.

Last edited by thuss; 12-06-2018 at 02:40 PM..
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Old 12-06-2018, 02:52 PM   #22
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Default Re: Panasonic led tv 55ds500

I hope these help
Attached Images
File Type: jpg IMG_1051.jpg (421.8 KB, 6 views)
File Type: jpg IMG_1050.jpg (239.1 KB, 6 views)
File Type: jpg IMG_1045.jpg (568.7 KB, 5 views)
File Type: jpg IMG_1040.jpg (596.7 KB, 6 views)
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File Type: jpg IMG_1043.jpg (693.4 KB, 5 views)
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Old 12-06-2018, 09:54 PM   #23
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Default Re: Panasonic led tv 55ds500

https://www.badcaps.net/forum/attach...0&d=1544133085
So all the red wires (Anode of LED strings) are tied together and fed by the V+ boost Voltage as I suspected.
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Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956

Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999

Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl

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TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Old 12-07-2018, 10:03 AM   #24
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Default Re: Panasonic led tv 55ds500

Can you provide the straight shot of the whole bottom side of the board?
Here is the training material to get some idea how the LED driver board functions.
http://service.panasonic.ca/pcs/EXT_...circuit_v2.pdf

Last edited by budm; 12-07-2018 at 10:50 AM..
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Old 12-07-2018, 01:51 PM   #25
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Default Re: Panasonic led tv 55ds500

.

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Old 12-07-2018, 10:07 PM   #26
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Default Re: Panasonic led tv 55ds500

I will do- I found the service manual for 55ds500

Thanks for your help had to order another backlight tester (mines gone walkies)


I wll do as it says on page 53 of the panasonic 2016 doc you attached- thanks for that

(and also panasonic 2015 page 52)

One thing I have noticed is that on page 72 of the document that I've attached (Panasonic 55ds500 chassis) on LDP1 I should be getting 40v on pins 16,17,18,19 and 20 but I am only getting half that i.e 24.65v
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File Type: pdf panasonic_tx-55ds500e_tx-55dsu501_chassis_km29e (1).pdf (14.46 MB, 12 views)

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Old 12-12-2018, 12:22 PM   #27
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Default Re: Panasonic led tv 55ds500

I've put the led backlight tester on the connections and they seem to be working.

One thing I have noticed/misunderstood between the service manual is that depending on the screen the voltages maybe different i.e 24v,36v or 40v from the psu to the led driver.

Any pointers would be appreciated
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Old 12-12-2018, 01:47 PM   #28
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Default Re: Panasonic led tv 55ds500

So what Voltage on the LED tester shows for each string, that is important info.
' 24v,36v or 40v" those are the feeding Voltage to the Boost converter circuit, not LED drive Voltage.
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Old 12-13-2018, 06:51 PM   #29
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Default Re: Panasonic led tv 55ds500

Quote:
Originally Posted by budm View Post
So what Voltage on the LED tester shows for each string, that is important info.
' 24v,36v or 40v" those are the feeding Voltage to the Boost converter circuit, not LED drive Voltage.

voltage was fluctuating from 20 to 25v

But I may have read it wrong the service manual clearly states 40v to the boost converter circuit - I'm not getting that 40v?
(i will double check the service manual)
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Old 12-13-2018, 09:10 PM   #30
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Default Re: Panasonic led tv 55ds500

You post #21:" The small one is rated at 44v.
1) If you trace out the + pin of that cap, it should go to the Power supply 24V output connector pin, so no way that the power supply will have 40 Volts output to feed the LED driver board, for safety margin, the cap will be rated at least 50 ~ 100% higher rated Voltage than the applied Voltage.
2) We already know that one for the LED string Cathode return show different Voltage than the rest.
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Old 12-13-2018, 11:30 PM   #31
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Default Re: Panasonic led tv 55ds500

BTW, what is the LCD panel model number?
Voltages spec. page 12 of your service manual shows VLED as 24VDC on 'P' board, I do not know why on page 25 is shown as 40V, in the training manual indicates the Voltage will depend on the LCD panel model number.

Last edited by budm; 12-13-2018 at 11:47 PM..
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Old 05-13-2019, 08:09 AM   #32
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Default Re: Panasonic led tv 55ds500

Sorry about the very late late late response- It was 8 leds gone one on in each strip on the left hand side.
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