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Another 2230 problem....

R

rtate

Active Member
So I 'm relamping with Don's leds but I can't get the "Stereo" indicator to work.
I switched to Aux but the indicator does not come on.
I tried to measure voltage with my meter but there is 0 Vdc both across the white and gray wire and also from each wire to ground :thumbsdn:

I'm not sure what the voltage should be as I didn't measure before I started :no:
When I measure the old lamps one is 19 ohms and the other is open...

What could the problem be??
 
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Just checking but you do know that the old style fuse lamps were for the dial display and the funtion lamps are a bipin soldered in lamp.
 
Yes I have the red bi-pins in the stereo indicator spot.
All other lamps have been changed to led's and are working fine.
It appears that there is no supply voltage for the "Stereo" indicator lamp.
Looking at the schematic it appears that power(14 vdc) is supposed to come from H801 whic is located on the main power supply board and I think I shouls get 14v between J805 and ground but i get 0Vdc??
Is this correct??
 
I have checked the mono button...
I have read about fm IC problems but I thought that the Stereo indicator should come on when in "Aux" mode.
I sure hope it's not a IC that's unobtainium!!!
 
no But I was assuming that was because the lamps were toast!!
I thought that in Aux mode the lamps should be on anyway...
regardless there is no voltage at the wires on the lamp mounting board...:no:
 
The stereo lamps get approximately +13 Volts from the power supply through R005, a 20 Ohm resistor. The 2230 doesn't use an IC for MPX decoding.

Tom
 
The old stereo lamps are in series, I believe. When one goes out, they both did.

If you replaced them with one LED, you must have it across the old connections.

Rob
 
rtate,
I was half-asleep last night when I read your post and overlooked your post #3 which questioned 0VDC between J805 and ground. The right answer is that you should read about 14VDC, not 0VDC. It appears that your P800 board has some problems that needs to be sorted out.
I am guessing that the receiver does not work at all for any inputs.
Another check of the P800 board is verifying that about 36VDC is read between J808 and ground. If this voltage reads 0VDC, the P800 board definitely needs some troubleshooting and repair before the Stereo lamps issue may be resolved.
Bill

PS Are the M002 and M003 lamps bi-pin incandescent lamps or LCD's?
 
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I'm not sure if I have the polarity correct on the lamps yet.
The schematic shows them in parallel( I think)
Even if the lamps are backwards there still should be 14v at the wires connected to the board, no??
12J5: the receiver functions fine except for the stereo indicator
I do have the 36 v at J808 but 0 at J805

The lamps are bi-pin leds from Don.

I'm thinking now that H801 may be a problem or what ever drives H801 as I dont seem to get any voltage on any of the legs of H801...
 
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rtate,
There is an off-board resistor, R018 (150 Ohm, 5W) mounted on a terminal strip J021 that drops the voltage from about 43VDC to about 29V that provides input to the H801 voltage regulating transistor. The R018 resistor appears to be located on the underside of the chassis next to the P800 board. Since there is 36VDC at J808 but 0VDC at J805 it is likely that the R018 150 Ohm resistor is open. The parts list in the service manual describes the resistor as a carbon resistor but the photo of Figure 7. Main Chassis Locations (Bottom View) looks as though it is a wire-wound resistor. I would check to see if the resistor reads 150 Ohms. If it is open, the resistor probably died due to temperature cycling over the years. Another possibility is that the soldered connections of the H801 transistor have failed over time and would need to be resoldered.
 
Thanks 12j5 forthe great info!!
I will check the resistor either later tonight or in the morning. I have company coming over for a bbq now....
Please monitor when you can...
 
troubleshooting update...

ok, so I found R018 , it is a ceramic wire wound and removed it.
It measured 159 ohm,well within spec.
I reinstalled and re soldered the wires at the P.S. board.
I powered the receiver and I got 43Vdc on one side and 0Vdc on the other!!
I measured resistance and got .1 ohm to ground on that side of the resistor!!
So Now I'm thinking possibly C804(330 50v) may be shorted??

Any suggestions??
 
Yes. I would remove the C804 cap and verify that the cap is shorted. Also check between the traces for C804 on the PC board and verify that the resistance no longer reads a short circuit. With cap out and the traces not shorted, it is safe to temporarily repower the receiver and verify 14VDC between J805 and ground.
Please let me know what you find!
 
I am gong through a 2230 now. The R018 on the unit I have was mounted on the top side of the board right behind H801. Kind of odd as this resistor gets HOT!!! It burned one of the wires leading to H801. I think I will mount on the underside and keep it away from the other components.

One more thought... the stereo indicator light should only work when there is an FM stereo signal present through the tuner. It will not work with AUX or Tape or other inputs (this is by design). switch to the tuner and dial in your favorite FM stereo station... then take a voltage reading.
 
On the 2230 - the "stereo" lamps will light in the "AUX" position - a direct connection to the (+) DC through a 20 Ohm resistor. That's the best place to set it when trouble-shooting the stereo lamps.

DH

megawatt said:
I am gong through a 2230 now. The R018 on the unit I have was mounted on the top side of the board right behind H801. Kind of odd as this resistor gets HOT!!! It burned one of the wires leading to H801. I think I will mount on the underside and keep it away from the other components.

One more thought... the stereo indicator light should only work when there is an FM stereo signal present through the tuner. It will not work with AUX or Tape or other inputs (this is by design). switch to the tuner and dial in your favorite FM stereo station... then take a voltage reading.
Click to expand...
 
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