Panasonic SA-HT820V Home Theater System

[CapsDude]

Re: Panasonic SA-HT820V Home Theater System

That is glue, the cap is not leaking, even if it was bad it would not cause the display to be like it is.

Oh, looked like othep pics of leaky caps. Right, I just thought it looked like it needed to be replaced. So besides visually, how do you check for a short with a multimeter?

[dick_barton]

Re: Panasonic SA-HT820V Home Theater System

Does the display board have a flat ribbon cable going off to another board. If it has I would check the gold contacts at both ends.

[R_J]

Re: Panasonic SA-HT820V Home Theater System

Oh, looked like othep pics of leaky caps. Right, I just thought it looked like it needed to be replaced. So besides visually, how do you check for a short with a multimeter?

I don't know what to say... You can use the ohm setting on its lowest scale, when you short the probes together, that is what a short would look like, 0 ohms (or close to 0) You likely shorted something and are missing a critical voltage or you blew the display driver Try and find out what created the burning smell. It was working (sort of) before so it is something you did, so go over everything that you removed or unplugged.
Check thatyou did'nt damage the cable P7201 between the display board and the main dvd interface. Can you locate L7200 on the display board? it should have +5volts on it

Download the service manual

[CapsDude]

Re: Panasonic SA-HT820V Home Theater System

Does the display board have a flat ribbon cable going off to another board. If it has I would check the gold contacts at both ends.

I don't know what to say... You can use the ohm setting on its lowest scale, when you short the probes together, that is what a short would look like, 0 ohms (or close to 0) You likely shorted something and are missing a critical voltage or you blew the display driver Try and find out what created the burning smell. It was working (sort of) before so it is something you did, so go over everything that you removed or unplugged.
Check thatyou did'nt damage the cable P7201 between the display board and the main dvd interface. Can you locate L7200 on the display board? it should have +5volts on it

Download the service manual

The cable from the display was my first guess since I forgot to unplug it several times when taking off the front and it would yank it. It was pushed up a bit at one end but I pushed it back down. The othes side tore off a bit tho because of the angle in which its bent to connect. The end that connects to the board looks fine.

I found L7200 and not getting a reading. Newb question, is it suppose to be plugged in and connected when checking it?

[R_J]

Re: Panasonic SA-HT820V Home Theater System

I found L7200 and not getting a reading. Newb question, is it suppose to be plugged in and connected when checking it?

Define "it" Yes the VCR needs to be plugged in, and Yes the connector needs to be connected to check for the +5 volts.
In sch11_14 (Pg3) , you will see Q33006, it is the 5V_vcc regulator, check the voltage on E,B & C.
sch27 has the power supply, check the voltage on P1102, are all the voltages their?
The blue stiff plastic being pulled away from the white flat cable is not a problem, the blue piece is to stiffen the cable to make insertion easier. You need to be careful with these cables or you will continue to damage them.

[CapsDude]

Re: Panasonic SA-HT820V Home Theater System

Define "it" Yes the VCR needs to be plugged in, and Yes the connector needs to be connected to check for the +5 volts.
In sch11_14 (Pg3) , you will see Q33006, it is the 5V_vcc regulator, check the voltage on E,B & C.
sch27 has the power supply, check the voltage on P1102, are all the voltages their?
The blue stiff plastic being pulled away from the white flat cable is not a problem, the blue piece is to stiffen the cable to make insertion easier. You need to be careful with these cables or you will continue to damage them.

I was referring to L7200, it read 4.94

For P1102 read

Pin 2 - 0
3 - 13
4 - 3.3
5 - -17.7
6 - - 23.7
11 - 6
12 - 6
All other pins are ground or he -+.

Haven't located Q3306 yet but some of those voltage reading seem low.

[CapsDude]

Re: Panasonic SA-HT820V Home Theater System

So apparently it's under the board, or at least the label is. I knew that! What am I checking? Because Im not seeing those letters anywhere.

And where online did you find the schematics for it?

[R_J]

Re: Panasonic SA-HT820V Home Theater System

I was referring to L7200, it read 4.94

For P1102 read

Pin 2 - 0
3 - 13
4 - 3.3
5 - -17.7
6 - - 23.7
11 - 6
12 - 6
All other pins are ground or he -+.

Haven't located Q3306 yet but some of those voltage reading seem low.

4.94 what?
P1102 pins 3&4 are the same connection, how can you have 2 different voltages? You must be reading the pins wrong. Check the voltages on the test points TL10xx instead. IP1240 is a fuse, check if it is still good.

[Diah]

Re: Panasonic SA-HT820V Home Theater System

My post #5 i wrote its mechanic issue and need to put all at zero point.

yours display photo its tell same you have Order JAM ( because the lost of zero point and there are 2 or more micro switch sending order.) though this can damage the main IC. not C or R.

[CapsDude]

Re: Panasonic SA-HT820V Home Theater System

4.94 what?
P1102 pins 3&4 are the same connection, how can you have 2 different voltages? You must be reading the pins wrong. Check the voltages on the test points TL10xx instead. IP1240 is a fuse, check if it is still good.

4.94 Volts.

Ok so I was reading the schematic wrong because its a little different from my power board. I was reading it in the opposite direction. So it should read:

Pin 2: 31.8V
3: 6V
4: 6V
5: 16.5V
6: -.03V
11: 3.5V
12: 13.4V

TL1004: 3.5V
TL1006: 6V
TL1009: 13.4V
TL1016: 16.4V
TL1030: -.33V
TL1038: 31.6V

Fuse read good.

[R_J]

Re: Panasonic SA-HT820V Home Theater System

Your problem seems to be that you are missing the Display -30 volts (UNREG_-30V) I suspect D1270 might be damaged. OR you have something on the unregulated -30v line that is shorted.
I suspect the the diode is burnt open or is shorted, and this is where the burnt smell came from.

[CapsDude]

Re: Panasonic SA-HT820V Home Theater System

My post #5 i wrote its mechanic issue and need to put all at zero point.

yours display photo its tell same you have Order JAM ( because the lost of zero point and there are 2 or more micro switch sending order.) though this can damage the main IC. not C or R.

I think we set the VCR to zero point but not the DVD. How do you go about doing that?

Here's the top and bottom. Do I need to take the trays out?

[CapsDude]

Re: Panasonic SA-HT820V Home Theater System

Your problem seems to be that you are missing the Display -30 volts (UNREG_-30V) I suspect D1270 might be damaged. OR you have something on the unregulated -30v line that is shorted.
I suspect the the diode is burnt open or is shorted, and this is where the burnt smell came from.

Do I have to desolder and take the diode out to test it?

[R_J]

Re: Panasonic SA-HT820V Home Theater System

Do I have to desolder and take the diode out to test it?

Check it on the board first, Use you meter in diode test and check it one way then reverse the leads and check it the other way.

[CapsDude]

Re: Panasonic SA-HT820V Home Theater System

Check it on the board first, Use you meter in diode test and check it one way then reverse the leads and check it the other way.

Negative (L) Positive (R): .324V
Positive(L) Negative(R): .202V

[R_J]

Re: Panasonic SA-HT820V Home Theater System

Negative (L) Positive (R): .324V
Positive(L) Negative(R): .202V

It is likely shorted, You can unplug P1102 and check the diode again (don't damage the cable) just to be sure, or unsolder one end of the diode.
If the diode is shorted, that would explain the way the display looks. It is likely that when the flat cable twisted and partly came out of the socket it shorted the unregulated -30 to ground as the pins are side by side.

[CapsDude]

Re: Panasonic SA-HT820V Home Theater System

It is likely shorted, You can unplug P1102 and check the diode again (don't damage the cable) just to be sure, or unsolder one end of the diode.
If the diode is shorted, that would explain the way the display looks. It is likely that when the flat cable twisted and partly came out of the socket it shorted the unregulated -30 to ground as the pins are side by side.

P1102 was already unplugged when I was doing the test. So if I wanted to fix it, is it a new diode or the power board itself?

[R_J]

Re: Panasonic SA-HT820V Home Theater System

Just replace the diode, that should get the display back to normal. and then you can get back to the other problems. Any 1 amp 200v fast recovery diode will work

[CapsDude]

Re: Panasonic SA-HT820V Home Theater System

Just replace the diode, that should get the display back to normal. and then you can get back to the other problems. Any 1 amp 200v fast recovery diode will work

Oh ok, I was already searching for a Panasonic 200V 200mA diode since thats what the schematic said it was. So it doesn't matter?

[R_J]

Re: Panasonic SA-HT820V Home Theater System

200ma 200v would be the minimum, that -30v supply is fairly low current, so any fast recovery diode greater than 200ma/200v would work.