Fixing Phillips LCD TV 37PF7320A

[RobPhotoPro]

Re: Fixing Phillips LCD TV 37PF7320A

It looks I will need more of your help afterall. I checked the diode out of circuit and it measured fine. The same for the second diode on that board.

So now I am lost. Would you suggest to replace the capacitors? They look fine and unfortunately I do not have a capacitor tester.

Thank you,
Rob

[PlainBill]

Re: Fixing Phillips LCD TV 37PF7320A

Not at this time. But there is something wrong with that diode showing shorted in circuit. What range were you using? I had (foolishly) assumed you were using the 200 ohm range.

PlainBill

[RobPhotoPro]

Re: Fixing Phillips LCD TV 37PF7320A

I have a Innova 3320 multimeter, it's autorange. It also has a diode testing mode, which I used after I took it out of circuit. I also used an ohmeter out of circuit, it was never 0.

When testing in the circuit, it measured inconsistently.

[RobPhotoPro]

Re: Fixing Phillips LCD TV 37PF7320A

Any ideas? Anyone?
Thank you!

[PlainBill]

Re: Fixing Phillips LCD TV 37PF7320A

Any ideas? Anyone?
Thank you!

Patience, grasshopper. I just spent two hours explaining to my wife and my daughter-in-law that I have no interest in taking a 3 week road trip to Florida.

PlainBill

[RobPhotoPro]

Re: Fixing Phillips LCD TV 37PF7320A

I bet! Florida is too hot for me in summer! :-)

[PlainBill]

Re: Fixing Phillips LCD TV 37PF7320A

I bet! Florida is too hot for me in summer! :-)

OK, I've downloaded the service manual. After staring at the schematics for half an hour I wanted to gouge my eyes out with a rusty spoon.

One thing that crossed my mind. This monstrosity uses a class D audio amp, which was a problem on other Philips TVs. Unfortunately, on this TV it's integrated into the standby supply, so it's not going to be easy to isolate it.

I'm going to try going back over the periphery of the diagrams and see if I can identify critical points to measure.

PlainBill

[RobPhotoPro]

Re: Fixing Phillips LCD TV 37PF7320A

Thank you, PlainBill. I appreciate it!
And as I mentioned before, when the TV is on for about 10 seconds, the sound works well, you can even change volume and channels without a problem. But no picture and then it all goes to protection..... I wish I had a couple of boards to swap, to at least identify the faulty board.....
Thanks again!
Rob

[PlainBill]

Re: Fixing Phillips LCD TV 37PF7320A

Thank you, PlainBill. I appreciate it!
And as I mentioned before, when the TV is on for about 10 seconds, the sound works well, you can even change volume and channels without a problem. But no picture and then it all goes to protection..... I wish I had a couple of boards to swap, to at least identify the faulty board.....
Thanks again!
Rob

Thanks for reminding me of that. That will limit the range of possible causes. In general, there are three possibilities.

1. One or more of the outputs of the power supplies go out of tolerance or is overloaded.

2. One of the DC - DC converters on the SSB goes out of tolerance.

3. One of the processors shut down.

PlainBill

[RobPhotoPro]

Re: Fixing Phillips LCD TV 37PF7320A

I have no idea how to diagnose or fix any of those. Where's my hammer?! :-)

[PlainBill]

Re: Fixing Phillips LCD TV 37PF7320A

I have no idea how to diagnose or fix any of those. Where's my hammer?! :-)

No need to use a hammer. When someone who shall remain unnamed gets around to identifying the critical pins....

Dang!!!! I know there was an easier way!!! As I recall, the schematic for the SSB is MUCH cleaner. And all the power inputs are grouped on one page.

I'll get back to you later. This just got easier.

PlainBill

[RobPhotoPro]

Re: Fixing Phillips LCD TV 37PF7320A

Sounds great! Thanks, PlainBill!

[RobPhotoPro]

Re: Fixing Phillips LCD TV 37PF7320A

After some time I got back with this TV. I measured the inverter boards inputs - flat connectors connecting inventors with Aux Power Supply board and noticed, they supply 24V, but no other voltage (like Bl_On). So it looks, Bl_On is missing and the question is, what board is in fault.

Any suggestions?
Thanks!

[budm]

Re: Fixing Phillips LCD TV 37PF7320A

Check the 100 Ohms resistor as shown in my pictures here:
http://s807.photobucket.com/albums/y...037PF9631D_37/

Very common problem due to under size resistor was used in the early production.

[RobPhotoPro]

Re: Fixing Phillips LCD TV 37PF7320A

The resistor seems to be fine, measures 100 ohms, as it should.
Thank you.

[budm]

Re: Fixing Phillips LCD TV 37PF7320A

Hello Bill,
I went to Elektrotanya to download the service manual for this Phillips "37PF7320A" and it comes up blank. Do you have the link to this? Thanks

[budm]

Re: Fixing Phillips LCD TV 37PF7320A

By the way, the BL_ON command generated in the main Controller board. I need the SCH to look at it to get exact pin out on the board.

[PlainBill]

Re: Fixing Phillips LCD TV 37PF7320A

Hello Bill,
I went to Elektrotanya to download the service manual for this Phillips "37PF7320A" and it comes up blank. Do you have the link to this? Thanks

That is common because Philips Service Manuals are tied to the chassis number. This TV has the BL2.3U AA service manual.

Here's the link to the service manual. It's in the third group of manuals.

PlainBill

[budm]

Re: Fixing Phillips LCD TV 37PF7320A

Hi Bill,
Ah, you use BL2.3U AA instead of the model number (37PF7320A) of the TV. I will download the manual and see how it works, thanks.

[RobPhotoPro]

Re: Fixing Phillips LCD TV 37PF7320A

Thanks for your help, guys!