Panasonic TX-37LX85P blink 3 times

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

I check whole IC, wrote voltages into picture.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

is it possible that transistor switch is bad? like Q5609 or Q5605 or Q5606 ?

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

OK, so the device is not being turned on. The VGS is 0V.
The power on signal disappears into the main processor IC1100.
Right now I would be considering replacing the main board unless something else faulty can be determined.

Did I miss something, or you get no +17V when power comes up (relay clicks?)
Using a resistor we could try forcing on power to PSU to see if it works.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

Yes you are true there is no 17V, what do you think shoud i try to force it up with resistor?

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

OK, this is the connection I suggest:

Pin (1 or 2) to 5, connect a wire between them (no resistor.)
Pin (1 or 2) to 6, also a wire (board has built in 1k resistor, no need to use one externally.)
Pin (1 or 2) to 15, connect a 470~4.7k ohm resistor.

PSU should power up, +9V, +17V, +24V should all work, along with standby rail +5.6V.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

i try connected as you sad, but nothing happen. The same 3 red blink.

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

Sorry if I wasn't clear but you need to disconnect the connector from the A board and see if you can get the PSU to work this way.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

Sorry my mistake, i tested it and it worked, but i don't have 9V on #11 and #12. All other voltages are OK (+24, +5.6,) And i can hear some strange sound like electric breaking, it is not loud, but you can hear that something is wrong. I think it is coming from reley or coil. and when i plug it out, i hear short whimpering.

I use 1.15kOhm resistor.

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

Is +17V good?

The +9V is generated from a sub DC-DC converter so this is likely the cause of the fault.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

What pin shud be +17V? I cant find i scheme. I have only 24V and 5V

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

Two pins from the last, I think.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

I dont have that voltage, i check but i think there is also +24V not 17V

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

OK, see the image. If anything in the image disagrees with what you measure, say so.

A voltage "when on" in this case indicates the jumper connections have been made, you can measure the standby 5.6V with the jumper in place.

The ground should be chassis of TV with PSU board installed and all screws fastened.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

i tested it, and i get 18V on #21 adn #22, but on #11 and #12 i have 24V, should be 9V, right? All other voltages are ok.

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

Ok, if there were 24V on the 9V I would say the main board would be damaged quickly, I guess it must be going into over-voltage protection (good idea from Panasonic, I guess.) I hope it hasn't been damaged but it is likely OK.

The +9V is generated from the +24V by IC854. What is the part # on IC854?

Does capacitor C850 get very hot when it is jumpered across?

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

IC854: MPD7S002
R84
08

C850 and C875 are hotter then other Capacitor, i tested it with thermometer probe it's around 50Celsius

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

Hmm, no result for that part number "MPD7S002".

Can you please double check it, if you cannot get hold of it you will need to find a way to give TV the +9V it needs (possibly by substituting in an additional supply, e.g. this one on ebay http://www.ebay.co.uk/itm/New-LM2596...item231ed973f5) or by replacing the power supply.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

I take a picture, you might recognize the image.

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

Ugh, yeah, I've seen those before. Ugly hybrid modules you can't buy from anywhere which Panasonic likes to use a lot. I don't know why they use them. Must be a good reason for it.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

http://www.chsinteractive.co.uk/elec...-panasonic.htm

i think this is it, i found it by PART NO.