Need help with connecting rds max to cyber max fm

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nickFF
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Need help with connecting rds max to cyber max fm

Post by nickFF »

Hi everyone.
I'm Nick, the RDS Software contest winner... and I got last week-end my beautiful reward : the CyberMAXFM 15W (DC 13.8V) DSP and its power supply.
I ordered it without the RDS board, because I already owned one (that helps to test the RDS code...)
Anyway, I mounted the RDS Max 3.0 into the Rack, wired Voltage, grounded, wired DSP out to RDS In and RDS Out to exciter In. When I turn power on, nothing from the DSP is transmitted (no audio and no 19Khz carrier to turn on the stéréo Led on my Tuner) . No led from the RDS board lights.
I tested: Voltage on RDS board=+15V, RDS board bypassed: audio transmitted. If you have any idea? thanks
.Nicolas.
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Post by pcs »

OK, first thanks for moving the topic here.

Now, first make sure that MPX audio passes through RDS board. Make sure
that everything is wired correctly, ie MPX out and MPX in are not interchanged.

Second, make sure power supply and ground (negative) are connected.

Once you get these above points correctly you will have stereo etc working.

By the way, do not connect I2C from RDS to stereo encoder or anywhere else. Leave it open.

Keep us posted.
Best regards,
Marko - PCS Electronics
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nickFF
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Post by nickFF »

"first make sure that MPX audio passes through RDS board. Make sure
that everything is wired correctly, ie MPX out and MPX in are not interchanged."
--> the MPX audio is wired like that:
audio -> Stereo Encoder -> RDS In - RDS Out -> exciter In
I checked that I haven't switched between MPX In and Out on RDS board.


"Second, make sure power supply and ground (negative) are connected.
Once you get these above points correctly you will have stereo etc working."
-->I wired power supply like that: for the positive, I added a wire between Switch output on MaxProIII board and screwed RDS board on the ground (negative) of the rack. Is that correct?

"By the way, do not connect I2C from RDS to stereo encoder or anywhere else. Leave it open."--> Ok, anyway I just left I2C alone...
If you want Marko, I can send a picture of the rack with evething mounted and wired if you need?
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Post by pcs »

Picture would really be helpfull.
Best regards,
Marko - PCS Electronics
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Turn your PC into a FM radio station!
http://www.pcs-electronics.com
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nickFF
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Post by nickFF »

Here there are the pics:
SE4DSP: Image
MAXPRO3 :Image
RDS3: Image
RDS3-BACK : Image
CYBERMAX15W : Image

If that can helps [-o< [-o<
:wink:

.Nick.[/img]
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Post by pcs »

I was hoping you'd be sending this to my email :roll:

Anyway, next to check would be whether any of your audio coax cables are in short, this happens quite easily
and often. Inner cable's isolation is sensitive to heat and can melt, creating short with the outer layer.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
nickFF
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Post by nickFF »

For the pics, that's true it would have been easier by email... :oops:
Let's say it was to test the new website interface... :wink: :^o :^o

About the cables: I tried to bypass the RDS board by putting a little piece of wire between the In and Out of the RDS Board, so the entire wire path was used in this case, and MPX signal was OK for the exciter.
.Nick.
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Post by pcs »

There is no supply power to the rds board than. Maybe you made a short from rds board to ground
and protection diode died?

Can you measure any voltage on the IC on the RDS board?
Best regards,
Marko - PCS Electronics
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nickFF
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Post by nickFF »

Here are the voltages I mesured: main RDS supply=+15.31V and on the pins of the 3 ICs, I have voltages between 0.1 and 0.4V max. Does that mean there is no supply on these ICs?
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Post by pcs »

It is very low. I suspect that at one point you made a short between the ground and power supply somewhere on the board.
This destroys protection diode. Replace this diode or short it and you're good to go.
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Marko - PCS Electronics
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nickFF
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Post by nickFF »

where is this diode placed?
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Post by pcs »

Next to the power supply connector, tiny smd 3-pin device.

Short it or replace with bat85 or similar low drop.


Best regards,
Marko - PCS Electronics
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Turn your PC into a FM radio station!
http://www.pcs-electronics.com
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nickFF
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Post by nickFF »

So I mesured voltage after this tiny 3 pins device, I have 14 V.
When I follow the path, I go to a transistor that turns very hot!! I think that's the consequence of the problem! this transistor reference is 78L09 - Y0345.
I immediatly turned power off but I don't knows if it hadn't been crashed :-?
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Post by pcs »

Ok, my guess would be that you have a short somewhere on the board. Perhaps this was done by
installing the PCB in the case? Something must be touching the metal somewhere.

There is a good chance that the device will work if you find and remove the short.
Best regards,
Marko - PCS Electronics
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Turn your PC into a FM radio station!
http://www.pcs-electronics.com
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nickFF
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Post by nickFF »

So I looked carefully the RDS board, but I'm not good enough in that matter to find the problem.
Is there any way to send back the RDS board or would it be cheaper to order a new one? :(
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Post by pcs »

Sure, mail it over (contact via email for instructions).
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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