Pioneer VSX-521, doesnt power up

[scampo77]

can anyone please help me find a schematic for this reciever?

I found a shorted output but only one of (what looks like to me) a darlinton pair. do i have to change both if only one is shorted?

they are part numbers 5160 (shorted) and D2390

there is a TO-220 case inbetween the darlinton pair, what is this?

K
C3964
133

[tom66]

Re: Pioneer VSX-521, doesnt power up

C3964 =

[scampo77]

Re: Pioneer VSX-521, doesnt power up

Thankyou so much for the reply I got the data sheet but was looking more for the purpose of that piece and if I should check or replace it.

I've never seen one in the middle of a darlington pair like this

[Tube_Dude]

Re: Pioneer VSX-521, doesnt power up

Thankyou so much for the reply I got the data sheet but was looking more for the purpose of that piece and if I should check or replace it.

I've never seen one in the middle of a darlington pair like this

Maybe the VBE transistor, used to stabilize the quiescent current of the output stage (Bias) in all temperatures of operation...

[scampo77]

Re: Pioneer VSX-521, doesnt power up

does anyone know where i can get schematics?

can i replace just one transistor in a darlington pair? (if only one is shorted)

[budm]

Re: Pioneer VSX-521, doesnt power up

[scampo77]

Re: Pioneer VSX-521, doesnt power up

BUD!!!! where have you been hiding?

thanks for the schematic!!!!!

[scampo77]

Re: Pioneer VSX-521, doesnt power up

i got the output in the mail and installed it and it still doesnt power up.

I followed the diagnostics sflow chart and right at the begining it says to check for 12v at plug CP1304. this seems to be a plug where the digital stuff gets its supply voltage from and it seems to come right from the power supply. i have 110v coming in and the fuse is good.

do these linear transformers fail? im not sure what to do next because the flow chart just says "if you dont have volatge then to check the main board. im not sure what to check next

the plug CP1304 is on page 102 of the schematics that bud was kind enough to put up.

[scampo77]

Re: Pioneer VSX-521, doesnt power up

can anyone offer some advice? i can take more pictures if it will help

[scampo77]

Re: Pioneer VSX-521, doesnt power up

I am still struggling with this amp and could sure use some help.

i put a picture up of the standby board what is FLAC and FLCT?

and standby relay has no voltage when i push the on off button.

I do have voltage (10v) at standby VCC

what actually happens when i push the power button? and shouldnt i have voltage to drive a standby LED?

HELP

[ajal14]

Re: Pioneer VSX-521, doesnt power up

hi there, i am facing a strange issue on my vsx 821. After reseting the unit it woks for days! after turn it off for hours , it go bck dead, no power! i have to reset it again to make it working for days!!!! i couldnt find any short on the main board or amp section. Any help? thx.

[mmartell]

Re: Pioneer VSX-521, doesnt power up

I will guess that FLAC is FLourescentAC for the display and maybe Flourescent Circuit for the other. Find out how to bypass the power button by jumpering at the HDMI board and see if listen for your relay to click. Or even easier tap it with the butt end of a screwdriver several times and press the button to see if it's sticking.

I think these also blow the small inline fuse on the primary winding of the transformer but I could be mistaken.