Dreambox 500s no power on

[joeh]

Hello everyone, I'm struggling with the repair of a dm500s on which he smoked the D46 component which is basically the diode screen printed with 1N4000 GW immediately behind the power connector but after replacing the decoder does not give any sign of life, what I could check why the rest SEEMS everything in order, no other component burned.

[stj]

Re: Dreambox 500s no power on

did you check the brick to make sure it still puts out power?

[R_J]

Re: Dreambox 500s no power on

That is a protection diode, He may have hooked up the wrong polarity adaptor to it, or the adaptor is bad.

[joeh]

Re: Dreambox 500s no power on

adaptor is ok and the L404 e L405 are ok

[stj]

Re: Dreambox 500s no power on

what voltage do you have across c422?

[joeh]

Re: Dreambox 500s no power on

12v present on c422

[R_J]

Re: Dreambox 500s no power on

Do you have any of the other voltages ? +3.3, +5 ?

[joeh]

Re: Dreambox 500s no power on

@RJ... on two regulators:
+5v ..... present about 4.9v
+3.3v....NOT PRESENT

[stj]

Re: Dreambox 500s no power on

i have a feeling we only have half the schematic.

[joeh]

Re: Dreambox 500s no power on

UPDATE:
By checking the voltage on both 3.3V and 5V regulators displayed in the picture, I read about 0 volt, then i think that the problem is here, then currently on the board and the regulators I have the 12v only, but missing the other two voltages +3.3v and 5v. I tried to replace both regulators, but the result does not change .... suggestions ???

[stj]

Re: Dreambox 500s no power on

both regulators?

your schematic just has ic40

[R_J]

Re: Dreambox 500s no power on

Just a note regarding the schematic, its the only one I could find and I know there are different versions and layouts. Here is another part that has some regulators on it
Or get it here http://elektrotanya.com/dreambox_dm5.../download.html

[R_J]

Re: Dreambox 500s no power on

Just a note regarding the schematic, its the only one I could find and I know there are different versions and layouts. I know some models use 2 seperate regulators instead of one.

[joeh]

Re: Dreambox 500s no power on

no schematic matching.....

[joeh]

Re: Dreambox 500s no power on

update on regulator 5v i have in output 3,7v and on 3,3v i have 0 v

[stj]

Re: Dreambox 500s no power on

found this.

[joeh]

Re: Dreambox 500s no power on

found this.

i have it yet...but no help

[risting]

Re: Dreambox 500s no power on

i have same problem with dm 500s dm is dead i connect another adapter 14v and i burn
33-16 W6 point, C422 replace new C422 and still no power no sign of life , and i no have any voltage on capacitor C125 when connect 12v adapter diode is very hot D46 i found dead ceramic capacitor L405 but i don't know corect capacitor NF to replace new one or processor is dead ? please help me sorry for my bad english

[SMDFlea]

Re: Dreambox 500s no power on

i have same problem with dm 500s dm is dead i connect another adapter 14v and i burn
33-16 W6 point, C422 replace new C422 and still no power no sign of life , and i no have any voltage on capacitor C125 when connect 12v adapter diode is very hot D46 i found dead ceramic capacitor L405 but i don't know corect capacitor NF to replace new one or processor is dead ? please help me sorry for my bad english

L405 isn`t a cap ,its an inductor/ferrite bead.

[risting]

Re: Dreambox 500s no power on

i solder ceramic capacitor and now i have heat on c422

maybe unductor is good my fault i no have any volts on start adapter is ok 12 v on receiver 0 volts