DM500s no voltage when plugged into lnb

[digitaldvd]

Hi all
can anyone help re this problem have replaced q72 as a suggestion on one off the earlier topics but this has not fixed the problem if another receiver is powering the lnb then the dm500 works no problem at all but if i plug the dm500s directley to the lnb the voltage goes to zero, and if no load goes back to 13 or 18volts seems to be a current issue any help would be appreciated
also now have some q72 if needed NDS352APCT-ND
I also tried the jumper trick if q72 is faulty but this did not fix the loss of voltage
Thanks

[best4less]

Have tried different power supply's????

[digitaldvd]

Thanks for the reply
there is now problem with the power supply as it runs my dm600 ok

[vinayr]

you did check the power supply ?

[digitaldvd]

yes

[beer4life]

Hi all
can anyone help re this problem have replaced q72 as a suggestion on one off the earlier topics but this has not fixed the problem if another receiver is powering the lnb then the dm500 works no problem at all but if i plug the dm500s directley to the lnb the voltage goes to zero, and if no load goes back to 13 or 18volts seems to be a current issue any help would be appreciated
also now have some q72 if needed NDS352APCT-ND
I also tried the jumper trick if q72 is faulty but this did not fix the loss of voltage
Thanks

G'Day,
The simplest things are not always obvious.
Have you checked your cables for shorts with a multi-meter as well as visual?
It's quite easy to get a strand of the braided shield causing a short when fitting the connectors.
This would cause the voltage drop.
Nothing ventured, nothing gained.
Kindest Regards, " the Druid ".

[Kavakid]

Bridge/resolder the fuse too, bad joints found here.

KK

[best4less]

When you say the voltage drops under load where are you taking your reading from, the outside of tuner, inside of tuner or on the circuit board.
I would be thinking of changing the tuner itself next.

good luck

[digitaldvd]

Thanks for the reply gee cant even remember where i measured the voltage but deffinetly found 18 and 13 volt dropped when under load, plugged into the lnb,the receiver is working perfectly if there is another power source eg another receiver powering the lnb.

[digitaldvd]

Thanks for the input there are no shorts on the cable as this is working with other receivers no problem but i will check and resolder fuse link maybe some luch here??
Thanks

[best4less]

I did a dream 7020 and swapping the tuner over fixed a similar problem for me
If it was me I would be grabbing another tuner and swapping it over.

[digitaldvd]

Yes it has been suggested that the tuner might be the issue but not sure why this would be as the 13/18v feed is for the lnb not the tunner as when another power source is feeding the lnb eg another receiver the dm500 is working perfectly, and as mentioned earlier q72 is not the problem i see z80 is around maybe he can help
Thanks

[Fernbay]

Try C4, as per this thread

[tuxmate]

Do you have a splitter on the line with single power pass? Does the second stb work at the dm500 end and/or the other way around?

[digitaldvd]

Try C4, as per this thread

thanks

[digitaldvd]

Do you have a splitter on the line with single power pass? Does the second stb work at the dm500 end and/or the other way around?

Yes i have a splitter in line with single power pass ,power pass is being feed by other sat receiver and dm500 is on splitter isolated from power and works a treat. maybe there is a dry joint but i will also check c4, everything is so small all the smds...
Thanks

[z80]

Try C4 as suggested by fernbay...it is on the PCB under the tuner module.

[digitaldvd]

Try C4 as suggested by fernbay...it is on the PCB under the tuner module.

Thanks for the reply z80 and also fernbay.
Question understand about pcb board under tuner is this the board that has only two components on it being a diode and a capacitor diode being d1 marking and the capacitor being c2 not c4 plus allocation for one capacitor not on the board marked c8, by the way the tuner is a BSBE1-705A
Thanks

[Fernbay]

Circled in red.

[digitaldvd]

Thanks fernbay
for the photos every picture tells a story mine looks very similar to your board but i only have two smd devices on my board one capacitor and one diodebut i will now check them out which is going to be a so and so .
Thanks