Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

[shepp]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

the main board is a 23292153, is the ICS located under the plastic cover? see attached

[vinceroger69]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

what mainboard does this set use ? and i use air duster spray hold the can upside down and spray the ics not as good as proper electronics freeze spray from maplin etc but certainly cheaper

[shepp]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

how do I freeze the ics?

[vinceroger69]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

if its a eeprom spi flash issue causing the reboots and freeze sometimes freezing the ics will make the set start up properly thats if it not a psu fault of course

[shepp]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

so your saying if you freeze the spi flash ics the set boots futher and stays on longer?
i have some psu s in my spares boxes i will look through them tomorrow and see if i have one

im not quite sure what you mean? I havent froze the spi flash ics....I havent got a clue what that is

but I am now checking U300 out and the surrounding components

[vinceroger69]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

so your saying if you freeze the spi flash ics the set boots further and stays on longer?
i have some psu s in my spares boxes i will look through them tomorrow and see if i have one

[shepp]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

yes fully boots, maybe it has got 5v and I cant reach the pin on the plug to test it while its on, but I havent found any 5v signals on the top side while powering up, just reading the link......and been searching for a board for it but cheapest ones like £40

[R_J]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

That post has a cleaner version of the schematic but all they do is take +12vcc through Q212 (base zenered) to get +5v Stby ( but shepp says q212 is not populated on this board)

[vinceroger69]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

maybe worth a read 5v is defently mentioned not sure if for standby though
https://www.badcaps.net/forum/showth...hlight=17IPS20
does the set fully boot if you freeze the eeprom/spi flash ics on the mainboard

[shepp]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

will any 17IPS20 PSU work or have I got to look to match the other number on the board?

[R_J]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

Being that it is actually a Vestel produced tv I dought the Panasonic codes will apply

[shepp]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

ok thank you

[R_J]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

It may not use 5 volts for standby, it may use the 12 volts as standby? Standby must be working or you would not have a blinking led and any codes. The 24 volts will shut down in standby
I dont have that manual
NOTE: Those codes are for a PLASMA TV, This is an LCD tv correct?

[shepp]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

right so its blinking 4 times twice, then when it reboots it blinks 3 times then 7 times

in standby I seem to lose the 24V off pin 1 and get 1.8v on pin 2

attached is the blink code info that I could find, any ideas anyone, im not familiar with the terms on the sheet, so is P-board is PSU and A-Board Main and also what is SU, SD, SC, SS-Board?

[shepp]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

Is this the 5 volts standby you are missing? try and follow the line back, it must lead to a regulator ic or diode and then check if its supply is working, I can't see the main board even turning on without 5 volts standby

Q212 for the 5v isnt even on the board its empty check pic no.2 right bottom corner of yellow box

and I cant find any 5v signals, found a 3.3 and 12v and 24v, think the 3.3v is for the backlight control and thats it, im gonna run through the testing again tomoz and post results just in case they have changed

[R_J]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

Is this the 5 volts standby you are missing? try and follow the line back, it must lead to a regulator ic or diode and then check if its supply is working, I can't see the main board even turning on without 5 volts standby

[shepp]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

ok sound advice, I dont think I read your original post properly before, my bad, problem now is figuring out why its rebooting, voltages look the same on the pins of the schemes anyway apart from there doesnt seem to be any 5v any where

this is gonna be one of them where I may have to guess which board is faulty and at this moment Im thinking it could be the Main Board not the PSU, but Its a vestel so its highly likely to be the PSU.......im getting the meter back out to investigate further, ill see if I can find any thing else out that might help someone to help me....or maybe find the fault hahahaha :-D

[R_J]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

This schematic is most likely for a different mfgr. Its the best available at this time, if parts are different or missing on your board, go by your board not the schematic. Many times they use the same pc board for different models ie 32" -50" and add or change parts accordingly
This is 17ips20 - (R2) <----
If its made for Panasonic, Hitachi, Vestel or anyone else its made to that mfg's specs Do search for this board using images and see the different configurations

[shepp]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

Is this close? The values etc. do look different, but it might be similar
It seem a lot of mfg's use the board and stuff it differently

some components are not on this schematic? is this correct? I cant find C283 C284 and I have no 5v Q212?

some things not quite adding up

[shepp]

Re: Panasonic TX-40CX400B - 17IPS20 - DULLSCREEN+ON/OFF/ON/OFF fault

Right .... so ive changed the Diode and the screen is nice and bright now, but its still switching off rather quickly, it powers up, I press menu, scroll and then it freezes and switches off then powers back on and so the cycle begins