Dear forum members,
Perhaps anybody can help me with the Sony KDL-40EX1 TV set. I have this set here for repair , but I have no experience with this type of TV. It has a media box and sents the TV information wireless tot the TV.
My problem is on the tv: no picture and no sound , the backlite works because I see white light behind the screen. There is also wireless communication because I can turn the TV on and off with the switch on the media box and on the TV itself.
I have the service manual but this doesn't really help me any. So the power board seems to be working because I have high voltage for the ccf tubes and 12V for the rest of the TV.
It is my idea that perhaps the main board is defective because I have no picture and no sound but I am not sure.
Is there anybody here on this forum that can help me with some idea's.
I have Philips 40PFL7007K/12 on repair. TV does not start up. I have checked the PSU and it seams to be OK. There seam to be problem on the main board.
What I have tried…
Well, there is +3V3-STANDBY coming from PSU to main board. This feeds up the main processor. This voltage has also been used to switch TV on. I have checked that switching signal from POWER ON button goes back to main board. But I did not check this whole path towards the processor as it is BGA package and it is covered by ceramic cooling plate.
And here comes what is not clear to me.
1. How to check if the main processor works? Does it work on the +3V3-STANDBY when TV is is standby mode?
2. Can I somehow check if the PSU is working? May be by activating some pin?
3. I have noticed by measuring (ohm-meter) some capacitors on the main board (in circles on the picture) that there is very low resistance on them (4.5ohms). In the scheme it is shown that these capacitors are on the 1V5 (1.5V) line. Is this OK? Basically it does not give much current as I = 1V5 / 4R5 = 333mAmps. What do you think? Certainly there are low voltage data parts (RAM. Processor …) connected and such resistivity might be correct….?....
What I have also find that this 1V5 is split into 1V5M0 and 1V5M1. See the picture. I have removed the coils and measured resistance. Then 1V5M0 shows about 15ohms and 1V5M1 shows about 6,5ohms.
The service manual is on this link:
A segítségeteket szeretném kérni a készülék tápegységének javításához.
Sajnos se a tápegységről, se az üzemi táp IC-ről nem találtam rajzot.
A tápegység átvizsgálásakor azonnal kiderült, hogy a meghibásodást a Q101-es MDF10N65B power FET Drain kivezetése és a "meleg GND" közötti C102 330pF-os kerámia kondenzátor anyaghiba miatti átütése okozta.
Elakadtam a javítással, mert nem találok sehol ilyen típusú(IC101: SC1S311) IC-t, de még helyettesítőt sem.
Üdv.: csabafi54 :)
I have a JMB JT 012203w/01 wide screen TV, the problem is with the VESTEL 171 PS61 ver 2 , Power Board , wanted to know the readings of the power out's of the 20 pin connector .