I have read that the "searching for satellite signal" in this model is
caused by a defective zener diode. common problem with
this model . Does anybody know where this defective diode is locate on
the circuit board and its value . The only thing
I know about it is SMT.

Thanks

Mike,
I found this with a "Google" Search...

Quote
"I have the RCA DRD430RA Receiver which is putting out 21 volts to the
LNB, instead of the proper 13/18 volts. This is causing the receiver
not to receive signals from the odd numbered transponders... now...

I am no genius when it comes to fixing electronics, but I know some
basics. I have traced the center pin on the coax connector back to
the power supply board, and found that it goes to an LM358 Op-amp. I
figure this is controlling the voltage to the LNB, and I believe it is
bad (BAD LM358, BAD!) :-)

But before I start soldering, I would like you experts 2nd opinion.
Here's the voltages at each pin relative to GND:

1. ~10mv
2. 9
3. 5.7
4. GND
5. 17.5
6. 16
7. 19.3
8. 20.8

It looks to me that the "A" side of the Op-Amp isn't functioning,
hence the nearly 0 volts on Pin 1. Do I have this right?

I guess I don't understand exactly WHAT the op-amp should output based
on the inputs, but I would think zero isn't right!?!?!

Thanks
"
Un-Quote

The "cure" below..

Also from "Larry"
Looks like I'm talking to myself again :-), but the fix worked!

The transistor is an NTE55 type, and is the one on the heatsink in
approximately in the middle of the power supply board.

Enjoy!


"Mike" wrote in message ...
I have read that the "searching for satellite signal" in this model is
caused by a defective zener diode. common problem with
this model . Does anybody know where this defective diode is locate on
the circuit board and its value . The only thing
I know about it is SMT.

Thanks

"David W. McGaffney" wrote in message
...
Mike,
I found this with a "Google" Search...

Quote
"I have the RCA DRD430RA Receiver which is putting out 21 volts to the
LNB, instead of the proper 13/18 volts. This is causing the receiver
not to receive signals from the odd numbered transponders... now...

I am no genius when it comes to fixing electronics, but I know some
basics. I have traced the center pin on the coax connector back to
the power supply board, and found that it goes to an LM358 Op-amp. I
figure this is controlling the voltage to the LNB, and I believe it is
bad (BAD LM358, BAD!) :-)

But before I start soldering, I would like you experts 2nd opinion.
Here's the voltages at each pin relative to GND:

1. ~10mv
2. 9
3. 5.7
4. GND
5. 17.5
6. 16
7. 19.3
8. 20.8


The 358 may be bad. The best way to tell for sure is to replace it with a
new one. Problems relating to op-amp IC's can be difficult to resolve. Often
the IC itself is OK but influenced by other factors (bad resistors,
capacitors, circuit board problems, etc).

Since pin 4 is GND, I would expect either a HIGH (source voltage) a LOW
(millivolts) or about mid-voltage from the outputs, pins 1 and 7, depending
on what the device is being "fed". In this case there are significant
differences at the inputs, so the high and low outputs may be correct.

Based on the voltages you give, I'm not convinced the IC is bad, but the
proof is in the pudding, so to speak. Replace it, they're cheap.

Mark Z.

It looks to me that the "A" side of the Op-Amp isn't functioning,
hence the nearly 0 volts on Pin 1. Do I have this right?

I guess I don't understand exactly WHAT the op-amp should output based
on the inputs, but I would think zero isn't right!?!?!

Thanks
"
Un-Quote

The "cure" below..

Also from "Larry"
Looks like I'm talking to myself again :-), but the fix worked!

The transistor is an NTE55 type, and is the one on the heatsink in
approximately in the middle of the power supply board.

Enjoy!


"Mike" wrote in message
...
I have read that the "searching for satellite signal" in this model is
caused by a defective zener diode. common problem with
this model . Does anybody know where this defective diode is locate on
the circuit board and its value . The only thing
I know about it is SMT.

Thanks