Panasonic led tv, 3 red blinks error, TH-L32X30M

[litec systems]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

There should be AVDD 12V at the pins of the LVDS connector on the main board, I would probe the pins of that LVDS connector on the main board side and see.
As far as the fuse, it should be labeled with F???? which is the typical designator for the fuse.
I cannot see the fuse from your pictures, may be upload hi-res pictures of the whole main board top side and bottom side for us to look at.

Here are few more pictures - is the black component that ive circled might be fuse although there's no any label on it( like 25v\1A etc)?

[litec systems]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

Is the Av switch could be the issue? ( looks like many ic's shares power within the same step downs
Here are pictures of ( all?) the step downs that I've found & around the tuner...

[budm]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

https://www.badcaps.net/forum/attach...0&d=1577668770
That looks to be inductor, it should show <1 Ohm resistance reading.
Boy! they only put the desigantors for the IC's and transistors but not for other passive components.

[budm]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

LV5857 step-down switching regulator.
https://cdn.badcaps-static.com/pdfs/...e954603180.pdf
https://www.badcaps.net/forum/attach...1&d=1577669137
You need to locate the inductor connect to the SW pin, then check the DC Voltage on the output dies of the inductor which is also connected to filter caps as shown in the example circuit in the spec sheet.
You can also check the resistance between SW pin and GND to see if the internal MOSFET is shorted out or not.

[litec systems]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

HI
Thanks again for your quick reply
sorry ive didn't got you on your previous reply ..youve wrote "The the meter between" and it tooks me a while to assume that thats an autocomplete and you meant to tell me what to test [before that ive thught that you just described how it works and not what to test..]
1.THE OUTPUT CAP has only 24v on the first`seconds[ till it goes into protection - then its starts to drop from 24v all the way to ZERO volts[this takes about 3.5minutes in order to fully discharge the cap] - all of this is while the red LED keeps blinking
2. because the ANtenna input have short to GND ive try to find the 3v (?) regulator and with the service manual ive reached to IC8700- which gets 16v from the PSU[ as should] and named "3.3v sub"- and on that output(pin 3?) im getting 3.975v[ till the protection starts]
and the regulator near it [ same model"IC8701"] -have A reading of ,6.195v[named SUB5V on the manual]
3. IC5000 readings( by pin #):
#1=15 v
#2=8.9V
#3=0.9- its triyng to start right before the protection starts
#12[panel sos]3V TILL protection starts[ shouldnt it work the opposite? when theres a fault the SOS reads 3v?
#15 3.2V TILL protection starts
#32= 3.3v-SD card -doesnt drop on protection
#31=sub5V-doesnt drop on protection
#30=***STB5v**-shows only 1.146 all the time - thats weird
#29=stb3.3- -shows only 1.416 all the time - thats weird
#28=**STB1.2 **3.273 on startup-3.266 on protection.... is that pointing on a bad regulator??
#27=STBRST- 3.357v TILL protection starts
#20=BUFF_EN-5.068V TILL protection starts
#18=BUFF_3.3_OUT- 5.068V TILL protection starts-** is that points on a short with pin20?- pin 18 named as a 3.3V OUT- but theres a 5V...
#17=BUFF_5v IN- no output

Hi
I've already tested these IC'S last week ( tge results are above)
BUT TODAY It looks like I've tested IN CIRCUIT few diodes, using diode mode, and found a bad diode ( or a bad components that connects to it)
Thats D4169,( it shows on p76&91) but ive attached pictures of the page
Anyway, on Diode mode test I've got ;
0.904v and when ive reverse the probes ive got 0.452 v
AND when ive tried to read real time voltage by turn the tv on, ive got 2.429Vdc ( for a half of a second, I've used the Max function again)

[nomoresonys]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

When in doubt lift a leg and retest out of circuit.

[litec systems]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

When in doubt lift a leg and retest out of circuit.

hi
ive tried that and the diode looks ok [reads 0.453V]- when im test the pad on the board- im gettinfg the 0.904v
is that ok?is there a way to identify the fuse of the tcon?

[litec systems]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

LV5857 step-down switching regulator.
https://cdn.badcaps-static.com/pdfs/...e954603180.pdf
https://www.badcaps.net/forum/attach...1&d=1577669137
You need to locate the inductor connect to the SW pin, then check the DC Voltage on the output dies of the inductor which is also connected to filter caps as shown in the example circuit in the spec sheet.
You can also check the resistance between SW pin and GND to see if the internal MOSFET is shorted out or not.

Hi
Is that could be the Tcon chip fuse? I'm getting steady 16.15v TILL PROTECTION.. On both sides even on the end of the MB trace till the chip...
If it is, then i think that ive already tested everything we've ever thought of ..
could it be an EEPROM issue althugh the tv is kinda responding ?
Do you have more ideas to troubleshoot? �������� I'm very passionate to got it work it's challenging me
Happy new year! ��

[budm]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

'N', that is s FUSE! you found 1 at least, great job.

[litec systems]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

'N', that is s FUSE! you found 1 at least, great job.

thanks ! and good to know & learn something new after all of those days
according to the pdf- its the only one on the mainboard- so its 1/1 all the others are on the PS
any suggestions how to proceed? ive even desolder the tuner

[litec systems]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

'N', that is s FUSE! you found 1 at least, great job.

Hi
Do you have any idea how to proceed?

[budm]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

I do not have any idea at this point. I need to look at the main board schematic in details to see where else to test.

[litec systems]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

I do not have any idea at this point. I need to look at the main board schematic in details to see where else to test.

Hi
Did you had time for it?
Or maybe someone else can help me out with this please?

[will62]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

In the SM that budm linked, I saw where it said that 3 led blinks indicates a
Tuner_SOS. In the next column under remark, it also mentions Panel_15V. If
you look at the block diagram however, it shows 3 led blinks is a T-Con_SOS.
If you don't narrow down anything on the tuner, I would check out the T-Con
voltage supply (see attached diagrams). Also, monitor what is happening on
the fault pin of IC4150 when you turn the power on.

[litec systems]

Re: Panasonic led tv, 3 red blinks error, TH-L32X30M

In the SM that budm linked, I saw where it said that 3 led blinks indicates a
Tuner_SOS. In the next column under remark, it also mentions Panel_15V. If
you look at the block diagram however, it shows 3 led blinks is a T-Con_SOS.
If you don't narrow down anything on the tuner, I would check out the T-Con
voltage supply (see attached diagrams). Also, monitor what is happening on
the fault pin of IC4150 when you turn the power on.

HI
due to my lack of luckyness .. while ive tried to test it - the tv came back to life for few secs[ ive hold the probe very careully- either it short to GND or just completed a broken trace
then ive turn it on- off to see if it still work and it was- when ive tried on the hird time- it died again but now i think it got worst
looks like the pa4150 fuse got blown and probably many other components-
IM hopeless now

[Kamal x]

تم الاشتراك