Zener DIODE HELP D6 - Element F0V87C

[kevinjo]

Re: Zener DIODE HELP D6 - Element F0V87C

I didn't use the cool spray. I just watched the difference netween the 2 sides to ground and was 23volts anode and 23.5 Cathode in reference to chasis ground.

[kevinjo]

Re: Zener DIODE HELP D6 - Element F0V87C

In reference to the anode and cathode while OFF there was identical or near identical readings ( straight across ) @.450 or so..can't remember number. While on I got similar results between the 2 sides measuring anode and cathode.

[kevinjo]

Re: Zener DIODE HELP D6 - Element F0V87C

Here is a graph of the DAMAGED Diode

[kevinjo]

Re: Zener DIODE HELP D6 - Element F0V87C

Think your right...4148 don't think will work. Testing..my old one goes to 1 volt on the test. Any ideas? If I missed a test..please explain.

[kevinjo]

Re: Zener DIODE HELP D6 - Element F0V87C

I tested a 3.3v Zener next to my SO CALLED DIODE ( program confirms ) and they look close.

[tom66]

Re: Zener DIODE HELP D6 - Element F0V87C

Your program does not show reverse bias, (a zener works as a normal diode forward bias, but has a low and controlled reverse breakdown unlike a normal diode)

[budm]

Re: Zener DIODE HELP D6 - Element F0V87C

"Raised it an inch off the board and put drops of coolant on it. As for voltage..the black mark cathode is 23.5 volts and the anode is 23.0."
Well, we are still trying to verify the Voltage readings when the TV DOES NOT WORK, and when you use the coolant on the diode to make the TV work, you should see difference Voltage readings when the TV works and when the TV does not work.

"I didn't use the cool spray. I just watched the difference between the 2 sides to ground and was 23volts anode and 23.5 Cathode in reference to chasis ground." So is this when the TV DOES Not work or when the TV is working?
For example of the Voltage readings when the TV does not and when the TV works: "my TV does not work when the 5V standby Voltage is at 4V, if I cool it down the OUTPUT is at 5V then the TV works again"
So what are the Voltage readings on the Diode when the TV works and when it does not work?

[Ltank]

Re: Zener DIODE HELP D6 - Element F0V87C

I have replaced a lot of zener diodes from 24v to 270v. Most were in the 27 to 48 volt range

[kevinjo]

Re: Zener DIODE HELP D6 - Element F0V87C

Please hold on this post for now. After more testing, there are more issues then just the diode. I can use this TV up to about a few minutes. It is starting to fail more often now. You can use the menu up to just before it shuts off. The menu will freeze and not respond. Then a few seconds later...it turns off until cool. There is no voltage other then the 5 volts when it cuts off. The diode which I am starting to think is ok after testing on the device I have. Does this sound like an EEPROM? It does work but not for long. I have changed the regulators as they where high. I suppose it could be a reflow issue???? Thanks everyone!!!! If I find something notable..I will add but for now..looks like I will have to replace the board unless someone has a more logical idea. Again, I think the diode is ok and thanks for the post helping me figure that out.