Hi everybody,
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:
http://elektrotanya.com/philips_ch.qfu1.1e_la.pdf/download.html
Thanks Martin
Sziasztok!
Kaptam egy 32phh4109/88 tipusú philips tv-t amin csináltam egy softwer frissítést és azóta hangolásnál akárhogy áligatom csak az analóg adásokat fogja be. Előtte fogta. Sajnos előbbi verziojú firmwarét nem találok. most tpn 350v van rajta. mi lenne a megoldás? Köszönöm.
üdv: keresek egy ilyen távot, vagy kérdezem, mi a helyettesítője(minden funkcióval).
Bálint
Dear Expert
The details of my TV is as follows
1. Philips 40PFL4707/F7 Manufactured March 2012
2. SMPS Board BA21P6F01 01 1
3. SMPS board has a sticker that says A21P6MPW C 7219720
4. This is a 110v Mains Supply TV sold in USA
5. I imported this from USA into my country where we have 230V.
6. I have a simple winding transformer that converts 230v to 110v
The TV has been having this problem. Here are the steps
1. Mains power on
2. Front panel white led blinks 6 times
3. Philips logo display
4. TV shuts down immediately
5. Nothing happens. If i press power button on TV or remote nothing happens
6. Have to power off and then wait for few minutes to experience same repetition.
Last two days, tried several times, only once the TV started and after 10 minutes it did auto shutdown as there was no input signal connected.
Does this indicate issues with SMPS or main cpu board ? Even if its faulty, how did it start once ?
More testing done as follows
1. Removed all connectors. Cleaned all three pcb with liquid cleaner. Cleaned all connectors externally and internally ( holes) using painting brush. Allowed everything to dry.
2. Reconnected
3. Started. This time, went past the Philips logo. I could connect a macbook via HDMI and play youtube videos on the TV for ~1 hours.
4. Using remote, entered service mode and initialized ( factory reset) the TV
5. For 1 hours of proper run, measured voltages. LED+24v was showing properly at 24v, AL+3.3v was at proper 3.3v and the P-ON-H1 was properly at 3.3v
6. After about 1 hrs, the screen shut down. The LED+24v is showing at 6v, AL+3.3v at 3.3v and P-ON-H1 is a 0v. This indicates the main cpu board has turned off the P-ON-H1 signal.
7. Power off, wait for 2 min. Power on... same philips logo and TV shuts down. Problem repeats.
8. Firmware is Code TVNB010_00_PF_XX91_BA PIC code U10_CM08:_40A_C7W_R_02. Did a google search and found no references if this firmware needs any upgrade.
requesting experts next steps to root cause the issue. I suspect the main board is bad and the SMPS is good. What if I manually put a wire from AL+3.3v to P-ON-H1 ? will the TV be on or is it risky for the main cpu board ?
I am attaching the service manual for this TV