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

[litec systems]

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

Renesas has a good intro to the differences between a linear regulator (LDO) and a switching supply.

With LDO's, you step down in voltage by generating heat. Output efficiency depends on the Vin-Vout difference.
With Switching supplies, you step down in voltage with a PWM controlled signal. Output efficiency gets as high as 95%+ with minimal switching losses.

Most supplies have over-current production as well as output short protection.

https://www.renesas.com/us/en/produc...egulators.html

Hi Thanks for your reply! 😊
If i understood you correctly and from what I've seen
The actual items for example are 7805 regulator VS~3$ step down modules on ebay?
If so, then i know these items ( not by thier professional name) but do know them as a device and I've just didn't knew thier professional name, but thats what I've meant to( I've been referred to them by LDO. As a step down, as actually they're both have the same job as" lowering the voltage "

[budm]

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

BTW, is there chassis number printed on the model number sticker on the back of the TV?
Did you also check to see if you do have 12VDC at both ends (with ref. to chassis GND.) of the SMD fuse on the T-CON board when you power on the TV?
Did you also download the service from the link I provided?
panasonic_th-l32x30d_chassis_km10.pdf. Main PCB TNPA5364.
I download this one and the LD board connector seems to match your LED board connector designator LD4, pin 12 is the BL-ON (STB pin of the LED driver IC), see page 71.
Page 75 also shows the pin names of the power supply connectors.
So look through that manual to see if it is almost match your TV chassis or not.
It may be very difficult to troubleshoot the main board down to component level if the schematic is not matched your main board.
Based on your pictures of your main board, your TV uses PCB TNP4G487.
The service manual from your links, the main board PCB is TNPH0906.

[litec systems]

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

Hi
According to the PDF that I've found( sorry for reffering mine too much, I've just didn't had time to look deeply at your's and I've read mine for the last days 5 days repetitively so I'm remebring most of it in my mind including page numbers \ sections😂but I've do download yours)
So according to that PDF and my understanding of the design ( if I've understood it correctly?) there's only a 16v rail and standby output from the ps to mainboard + 24v to the led driver
All of them exist and steady
There's a 12v reading on the capacitor on tupper side of PSU
( the schematic says " process voltage converter" - screenshot attached.. so maybe there's a step up to 16V to MB and\or 24LED from that one? Or it's for the IC'S on the other side of the PSU ( This cap is pretty big so more likely it is used for a greater load than few ICS on the back)

I've wanted and think about an open fuse on the TCON,
But There's no separate Tcon board on this tv , its probably combined on the panel, and I've try to locate a Fuse there too but its too crowded and didn't find one ( at least not accessible one..)
There are many test points on the panel near the LVDS input but they are too close to the chasis and I'm afraid of accidently short them to ground with the probes)
I'll try to deeply read your PDF ASAP probably on Sunday when I'll be at home..
And here's few pictures of the chassis, I've tried to figure out and look for chassis # but didn't find a clearly one, but maybe it's" Tmb4g"? That's the only repetitive letter that I can see on all of the stickers on the ports
Thanks for your help!

[budm]

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

https://www.badcaps.net/forum/attach...3&d=1577397767
So there is no T-CON board under that black plastic at the bottom center of the LCD panel, correct?
If it has integrated T-CON then there should be fuse by the LVDS cable of the integrated T-CON.
We need hi-res pictures of that integrated T-CON boards.

[litec systems]

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

Hi
Yes, it is an integrated one unfortunately,
I've thught of it but as I've said it not accessible one ( if any) There are only unlabeled test points and LVDS access. Let me know, if its necessary ill disassemble the LCD panel tomorrow ( Sunday) And look for a fuse\ damaged diodes there
BTW, let's say that I'll do find a bad fuse there, and ill check of there's short to ground between each side of the fuse. Isnt that mean that it's been blown due to overcurrent and it will fail again soon or it can be blown due to a peak?
Anyway, here's the PDF of the panel- I've try multiple times to search that pdf for an " F1/ fuse " with no success
And a picture of the only accessible things on that integrated TCON before taking it apart( carefully)

[budm]

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

To get to that T-CON/TAB bonding board, you will have to remove the metal from the LCD panel assembly, so at this point lets look first for the 12V at the LDVS connector on the main board first. Please upload good hi-res pictures of your main board.

[litec systems]

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

Sorry, I've forgot to paste the link for the LCD panel PDF( in case that I've missed out the fuse there(-if any?)
so here it is
https://www.datasheet4u.com/mobile/9...32H101G00.html

And here's pictures of the LVDS section & screenshot of the PDF of IC'S 4120+4150

[budm]

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

Page 8 1/4 of the LCD panel spec you provided, it shows you what you should have on the notes.

[budm]

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

BTW, the main board lay out from your Panasonic TC-L32E3 service manual link does not match your board in your TV, see page 53 so you cannot go by what is shown on the service manual and what your TV actually has.

[litec systems]

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

Page 8 1/4 of the LCD panel spec you provided, it shows you what you should have on the notes.

Ive seen this page before but ive got confused from the next page[#9] between pins 10-11\12-15\5-10 [ because usually there are 3-5 Vcc pins and usually theyre on the most left\right ones on the competitors ] so now with your attention - if ive understood correctly-pins 10-11 are the 12v in right?

[litec systems]

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

BTW, the main board lay out from your Panasonic TC-L32E3 service manual link does not match your board in your TV, see page 53 so you cannot go by what is shown on the service manual and what your TV actually has.

thanks for your attention
now i should compare the pinouts from p71 to the actual board [IT LOOKS EXCACTLY THE SAME MODEL the PDF that youve found - thanks!!]and test each one with the meter to confirm there are proper voltrages? then look for 3.3&12-15V tcon supply and see if there are proper voltage readings?
anything else that ive forgoten? [ althugh that it looks to me like the PSU is ok and its 90% MB problem\10% bad panel\fuse ] am i right?

[budm]

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

Per LCD spec sheet page 8 1/4, pin 12 ~ 15 (of the LCD panel connector, not the connector on the main board) are the AVDD pins which should have 12VDC.
Pin 1 on the main board may be pin 60 on the LCD connector, you have to verify that, but at least now you know that at least 4 pins of the LVDS should have 12VDC, so see if any of them has 12VDC, just have to be careful and use probe with small sharp tips.

[litec systems]

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

Per LCD spec sheet page 8 1/4, pin 12 ~ 15 (of the LCD panel connector, not the connector on the main board) are the AVDD pins which should have 12VDC.
Pin 1 on the main board may be pin 60 on the LCD connector, you have to verify that, but at least now you know that at least 4 pins of the LVDS should have 12VDC, so see if any of them has 12VDC, just have to be careful and use probe with small sharp tips.

ok, just for learning what's the "AVDD " stands for and what are p10-11 VCOM?are the VCOM are the PSU GND TOO or what?
thanks in advance!

[budm]

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

LCD panel power supply topology.
http://tvrepairsolution.blogspot.com...lcd-panel.html

[litec systems]

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

LCD panel power supply topology.

thanks alot brother ill read this and today ill continue the tests and let you know
thanks alot and have a good evening !

[litec systems]

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

Hi
So I've disassemble the LCD panel, THERE IS NO FUSE "F1" THERE, SO, ive try to test 12-15 pins with a tinned probe, and the Meter almost shows a reading then the protection starts. So I've decide to use the " max " function of the Meter and I've got 2.309V it was pretty difficult to point the probe there, there's a 0.1% that I've put on the Vcom
Anyway, there are pros and cons between the schematic that we've found, there are things that are detailed in one one that I've found and vice versa... So i have the merge all that info in my mind,
Then I've found few interesting details,
Such as, IC4150, ( labeled as TCON DC DC) on p31 of yours( and p28 of mine- which gaves me a HUGE hint, there's a fuse ( labeled pa4150) between that ic to the 16V PSU rail
So if you Can, i need your help please with identified it( if you want to find more fuses, i suggest you to search for PA4150,( thats the particular fuse) and on page 70( of mine pdf) you'll see there 3 more fuses on the mainboard, so maybe one or more of them is shorted( I'll appreciate your help to find them on the circuit it's a very crowded and full with many components)
AND, im think that i have to test& find the 3.3&1.8v, cause it looks like they're both goes to the tuner and it's shorting for some reason between the Ant pins..( ive think about desolder the tuner ( but im afraid that it'll be difficult to me with my current equipment & ( lack) of skills) I've found 3.3v&1.8 step downs\ LDO'S ( one of each) but IDK if they're more in the circuit

[budm]

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

Since there is hardly any AVDD which is generated by the main board, so at this point something on the main board is the problem or the AVDD on the that tab bonding board is loading it down. You can try disconnecting the ribbon cable from the LCD panel and and see if you will see any 12V on the LVDS connector.
It is difficult to troubleshoot the main board without having matching schematic. Finding and checking the 3.3&1.8v is a good idea.
BTW, the panel is not fully integrated T-CON since the avdd, vcom, vgamma are generated by the main board.

[litec systems]

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

It is difficult to troubleshoot the main board without having matching schematic. Finding and checking the 3.3&1.8v is a good idea.
BTW, the panel is not fully integrated T-CON since the avdd, vcom, vgamma are generated by the main board.

Your PDF is excacly the same mainboard fortunately, it's just lack few things ( and vice versa at mine PDF) such few detailed information such fuses
I've thught about that it's not a fully TCON. As I've didn't see there any square IC which is usually there
Do you have any suggestions how can i identify the fuses on the mainboard ( there's no f1-4) how it should look like? ( color or marking on the SMD itself)?
There's a 1.8V step down near the tuner, and a3.3v one (IC8700) that I've mentioned last week, both have an output
Can it really be the tuner itself ? ( the error code is panel vcc\sub3.3v, but I'm afraid that I won't be able to desolder it properly, but I've test continuity on my tv's at home and no one of them beeps so It looks like it is related
And about testing the LVDS pins- you think that I'll be able to PERFORM this or the mainboard will identify that there's nothing connected and avoid even send the voltage?

[budm]

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.

[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.

IVE tried multiple times to find F1-4\f on both MB & pdf with no successes- only found PA4150 for IC4150[tcon dc dc] on te pdf- but cant find them phsyically even with magnifier
ive tried to point the prob to the MB -and didnt got any AVDD there
ive tried few random pins of the TCON DCDC [IC4150] and do got few 16V INPUT[ probably directly from the PS]

ive tried to read the SUB tuner pins[unused pins-maybe for LNB tuner] and ive got :
steady 5v+1.8+3.3 till protection-BUT one 3.3 pin had 3.3 THEN BEEN DROPPED TO ~2.7 THEN UP TO 3.3 AGAIN then- one second later the tv turns to protection-am i found something or maybe the tuner uses pins with voltages for communicatin like LVDS?

NOTE - THE 16V rail is comletely shutting down while protection so that all the mainboard [ but standby] is being disable as it works only on step down from that 16v-BUT the 12&24v PSU caps still have a steady readings
i dont know what else to do (((((((((((((((((