Home Theater Forum and Systems banner

1 - 4 of 4 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
Hi guys, first post, but avid lurker. I hope that you guys can provide me with some guidance.

Let me bring you speed:

P50S601 been abused and left on for many, many hours. Left for vacation, unit still plugged in, but on Stand-By. Unit is plugged into Onkyo receiver, and powered on by the receiver.

Came home from vacation, switched on the receiver, unit powered on, but no picture. No flashes, just solid Blue light. Tried to adjust volume and input, but noticed that light blinks 3 times when a button is pressed. This happens with the remote or the buttons on the tv. NEver heard any sound, or any resemblance of a working TV. Decided to power off and go to bed, but unit will not power off or respond in anyway. THe only way that it will turn off is by cutting power at the surge protector. Weird thing is that when power is restored, unit powers on by itself and goes from stand by to "On".

Found this section of the forum and read about all the issues with these Hitachis and similar models. Dove right in and removed the back, and of course the Caps were swollen. IC's look good, but not tested at this point can't get my loser friend to bring back my meter. I went ahead and ordered the caps from Digikey, and replaced them. Unfortunately, they were not the only problem and the unit does the same thing. I decided to pull the ribbons off of the upper and lower boards to see if I could isolate one that might have an issue. No go, still acts the same.

Obviously, I still need to test the IC's, but I have a feeling that they are not the problem. They look pristine, but have not been tested to confirm.

Is there anything else I should check or start to look for?

I don't have the service manual, and can't seem to find one. I thought that I had seen it while researching the problem, but now can find it again.
 

·
Registered
Joined
·
104 Posts
You got my attention when you mentioned that your TV was plugged into (powered by) your receiver.
I would have never thought that was an option as PDP are pretty power hungry.
Does your receiver totally shut off power to the TV when it powers off?

Anyway, you are at a stand still until you measure the ICs on your SDR boards.
For what you need to do a cheap $10 multimeter will do. (always have backup multimeters... I have 2 in my garage and carry one my truck!).

There isn't anything else you can check for without the right specialized tools and equipment.
Consider us lucky that the main thing that goes wrong with these set can be diagnosed with a common multimeter.

Good Luck!
 

·
Registered
Joined
·
2 Posts
Discussion Starter #3
Yeah, I still need to test the ICs. I am going to purchase a cheap back up meter this afternoon. I am somewhat skeptical, especially after seeing your thread. Seems like a similar problem. I tried to do what you did to make your set work, but to no avail. It did allow me to use the power switch to turn it on, but still no picture. I think there is something else besides IC's going on.

BTW, the Onkyo never had a problem powering the TV. It handled it fine for three years until now. I have eliminated the receiver as part of the circuit while testing.

More clarity on the issue....when the AC is applied, unit turns on with two clicks, a few seconds later and before anything comes on the screen, it clicks again.
 

·
Registered
Joined
·
104 Posts
More clarity on the issue....when the AC is applied, unit turns on with two clicks, a few seconds later and before anything comes on the screen, it clicks again.
This sounds like the very same thing that was happening with my unit.
Leonard thought there maybe an another be a cap with bad DA or a reset circuit that is malfunctioning.
I read up on reset circuits for these SMPS but nothing caught my untrained eye.
If I ever get a chance I would change all the e-caps for good measure and to eliminate the possibility of my issue being caused by bad DA.

Be sure to disconnect all components (XSUS, YSUS, LOGIC Board) from the PSU and power up your set to see what happens. (I'll bet the the power supply stays on) I would also test the voltage across the pins as specified in the power supply troubleshooting flow chart in your service manual while those components are disconnected to see what readings (if any) you get.

BTW, the Onkyo never had a problem powering the TV. It handled it fine for three years until now.
I'm going to have to take a look at those Onkyos. I had no idea they could handle a TV set. Every receiver I've ever own only had 2 prongs (not 3) back there.
 
1 - 4 of 4 Posts
Top