Toshiba 49L621U

[hoodyracoon]

Re: Toshiba 49L621U

yeah my tv doesn't have a firmware update on Toshibas site anyhow, so its like i thought if i have a issue with firmware i would need to flash it via a eprom flasher or rs232, and thats if i could get the file, don't think it is just looking at my options

[nomoresonys]

Re: Toshiba 49L621U

https://www.ebay.com/itm/Toshiba-49L...UAAOSw1J5aowFW For 20 bucks and free shipping, I'd give that a shot.

[kristapMA]

Re: Toshiba 49L621U

you have TOSHIBA LOGO show on screen at start on. this is much belong to glitch at firmware. as TOSHIBA very known with poor firmware. there are update from August 2017 to this model . download it and follow how to PDFfile with same link. you must match the firmware to your model size in your case 49 to let the INIT_CLEAR.prg work at start up when you plug in the USB first then the electric wall cord

if this didnt help you. i go to judgment the Background edge LED one of line are shorted

can i update the firmware if i can't see the screen?

I am getting ready to do the testing from a few posts up as I haven't done that yet but not sure how to update the firmware as i have never done that before.

[kristapMA]

Re: Toshiba 49L621U

BTW, can I get straight shot pictures of the whole bottom side of that power supply board Toshiba PK101W1230I?
Shopjimmy does not have it.

Here is a pic of the bottom of that board.

[kristapMA]

Re: Toshiba 49L621U

Something does not look right: pin 1,2, and 3 16V2. What does it mean 'ALL THE WAY'?
Pin 8 is also 16V2 but you show '0V', it should show the same as pin 1 ~ 3.
Please verify your measurement.

I redid the pins and got different numbers. I must be doing something wrong then? I don't get it... my son took a video while I was doing it, maybe someone can tell me what i am doing wrong... I am trying to figure out how to upload the video from my phone and will post when i figure it out.. in the mean time here are the numbers i got...

Standby
1 - 0 - 16v2
2 - 0 - 16v2
3 - 0 - 16v2
4 - 0 - gndp
5 - 0 - gndp
6 -0 - 16va
7 - 0 -gnda
8 - 0 - 16v2
9 - 0 - gndp
10 - .2 (ish) - 5v1 - needle moved a tiny bit
11 - 0 - acd
12 - 0 -pwon
13 - 0 -blon
14 - .2 (ish) - 5v1 - needle moved a tiny bit
15 - .2 (ish) - dim
capacitor - 0v
capacitor - 1v

POWER ON

1 - 1 - 16v2
2 - 1 - 16v2
3 - 1 - 16v2
4 - 0 -gndp
5 - 0 - gndp
6 - 1 - 16va
7 - 0 - gnda
8 - 1 - 16v2
9 - 0 -gndp
10 - 0 - 5v1
11 - .2 ish acd
12 - 0 -pwon
13 - 0 - blon
14 - 0 -5v1
15 - 0 - dim
capicitor - 3v
capicitor - 3v

i can't figure out how to attach the video so I uploaded it to youtube. https://www.youtube.com/watch?v=3jhNrz11i9Q

[budm]

Re: Toshiba 49L621U

Must be error on your meter or how you have the probes connected, or meter setting or meter is dead since now you are getting basically 0V.

[budm]

Re: Toshiba 49L621U

Here is a pic of the bottom of that board.

I am talking about the bottom soldered side of the board.

[kristapMA]

Re: Toshiba 49L621U

I am talking about the bottom soldered side of the board.

ooops sorry i misunderstood.... How do i take it out without damaging anything?

[budm]

Re: Toshiba 49L621U

Take pictures first so you have the record of how the connectors are in place.
1) Check the Voltage between the two legs of the main filter cap to make sure it is discharged do to 10V or less first.
2) Carefully remove the connectors and then the mounting screws to remove the board.

[budm]

Re: Toshiba 49L621U

I redid the pins and got different numbers. I must be doing something wrong then? I don't get it... my son took a video while I was doing it, maybe someone can tell me what i am doing wrong... I am trying to figure out how to upload the video from my phone and will post when i figure it out.. in the mean time here are the numbers i got...

Standby
1 - 0 - 16v2
2 - 0 - 16v2
3 - 0 - 16v2
4 - 0 - gndp
5 - 0 - gndp
6 -0 - 16va
7 - 0 -gnda
8 - 0 - 16v2
9 - 0 - gndp
10 - .2 (ish) - 5v1 - needle moved a tiny bit
11 - 0 - acd
12 - 0 -pwon
13 - 0 -blon
14 - .2 (ish) - 5v1 - needle moved a tiny bit
15 - .2 (ish) - dim
capacitor - 0v
capacitor - 1v

POWER ON

1 - 1 - 16v2
2 - 1 - 16v2
3 - 1 - 16v2
4 - 0 -gndp
5 - 0 - gndp
6 - 1 - 16va
7 - 0 - gnda
8 - 1 - 16v2
9 - 0 -gndp
10 - 0 - 5v1
11 - .2 ish acd
12 - 0 -pwon
13 - 0 - blon
14 - 0 -5v1
15 - 0 - dim
capicitor - 3v
capicitor - 3v

i can't figure out how to attach the video so I uploaded it to youtube. https://www.youtube.com/watch?v=3jhNrz11i9Q

So did you verify that your meter is OK since you are now basically getting 0V readings?

[budm]

Re: Toshiba 49L621U

BTW before we get too deep, do you have proper tools to do component level replacement, especially the SMD (surface mounted parts)?

[kristapMA]

Re: Toshiba 49L621U

So did you verify that your meter is OK since you are now basically getting 0V readings?

Pretty sure i had it set wrong... going to take the tv apart today so will double check before i even think about taking the board off but wanted instructions so i have it...

[kristapMA]

Re: Toshiba 49L621U

BTW before we get too deep, do you have proper tools to do component level replacement, especially the SMD (surface mounted parts)?

I have basic tools so most likely not. But if it will save me money to fix it myself, I will get the tools i need. My husband did say if something needed to be soldered that we will take it somewhere because he isn't confident that i can do it. I have watched my dad and brothers solder things that I think with instruction I can.

[budm]

Re: Toshiba 49L621U

If I were you I would buy a digital meter right now, it will make it much easier to troubleshoot the problems.

[nomoresonys]

Re: Toshiba 49L621U

http://tvna.compal-toshiba.com/us/en...=529&model=544 Right there is the download page for 49L621U, instructions should all be there, just be sure to follow them exactly.

[Nvbenv]

Re: Toshiba 49L621U

Can anyone tell me the volt and UF rating at c603 on the power board. It is a green cap. Please

[budm]

Re: Toshiba 49L621U

Show us good clear picture of your C603? Is it missing on your board? What section is it in?

[jostewcrew]

Re: Toshiba 49L621U

i hhave a question about this 49l621u model. changed power supply, main board and tcon board to a set that had power, backlight flash on with toshiba logo, then went black with red led flashing 5 times. leds were good and again new pb, mb, and tcon with same issue. also downlaoded and flashed firmware for this model (dont know if it took as it was a black screen) read the posts about blon and dim (pins 13 and 15 respectively) and disconnected the dim from the connector. fired right up.

troubleshooting the power supply and main board connectors at the blon and dim gave 0v both when off, and 3.3v at blon and 2.9v at dim when turned on. being that dim is disconnected from the power supply side of dim, it would be as blon is 3.3v and dim is at 0v.

Question:

is the blon and dim originated from the powersupply board or the main board? if it the main board, is it safe to say that there is some variable resistor or something that dictates dim voltage? if so, in theory, i could replace the resistor ir ic and it wont suck all the voltage from blon turning off the backlights correct? any insight is appreciated.

[budm]

Re: Toshiba 49L621U

i hhave a question about this 49l621u model. changed power supply, main board and tcon board to a set that had power, backlight flash on with toshiba logo, then went black with red led flashing 5 times. leds were good and again new pb, mb, and tcon with same issue. also downlaoded and flashed firmware for this model (dont know if it took as it was a black screen) read the posts about blon and dim (pins 13 and 15 respectively) and disconnected the dim from the connector. fired right up.

troubleshooting the power supply and main board connectors at the blon and dim gave 0v both when off, and 3.3v at blon and 2.9v at dim when turned on. being that dim is disconnected from the power supply side of dim, it would be as blon is 3.3v and dim is at 0v.

Question:

is the blon and dim originated from the powersupply board or the main board? if it the main board, is it safe to say that there is some variable resistor or something that dictates dim voltage? if so, in theory, i could replace the resistor ir ic and it wont suck all the voltage from blon turning off the backlights correct? any insight is appreciated.

BL-ON and DIM are controlled by the Main board. BL-ON <1V = OFF, > 2.5V = ON. most TV uses PWM DIM control signal.
1) So what do you have on DIM pin if all cables are put back in place?
2) What DCV do yo have on the LED connector of EACH pins when you first turn on the TV (you will need to leave the meter probes in place, black probe on chassis, red probe on each LED connector) and then after 10 seconds then turn the TV off, so you have to repeat this test on each pin of the connector that has the wire connected to it, you also need to provide the pin name so we can easily see what it has or does not have..
3) We need good clear pictures of the whole back side of the TV showing all the board.
4) We need close up pictures of the LED connector so we can see how many wires it has and which pins the wires are connector too.
5) You must follow instructions as requested.

[jostewcrew]

Re: Toshiba 49L621U

sure thing. i will get all of this together and place back all wires. i will post back when ready to begin from the beginning. thank you!