Need help, fixing onkyo tx sr507, bad channel, blown fuse.

[cwolford]

onkyo tx sr507:

Had it a long while, been through a lot and dont have funds for new one.
Found a nice schematic. All tho I am not the best at reading it.

I don't know all my components or how to test them. I do have a nice soldering setup and a alright DMM. could make a make shift bench top psu if need be.

Short of it:

It went in to protect mode aka blinking light. I turned it back on, smoke came up from PSU area. Fuses blown.

Was it the fuses that smoked?

looked it over, got new fuses. they went bad too.

IT POWERS ON, IT HAS VIDEO OUT THE HDMI. NO SOUND.

don't recall how to check transistors, but I know they should not be shorted.
based off schematic Q6060, q6050 are the ones shorted. seem to be front left.

I know I need to replace them. what else do i need to check?

Until i get parts can I rob the parts from zone 2 aka not the 5.1 but the extra set. I dont use them, if i understand right the 4 transistors on the left in schematic are for zone 2 they seem to be the same stuff, numbers and all.



The day it went bad:

there was a lot of power surges, looked out side and there was 2 street lines arcing.

IT had just been re hooked back up from its hiding spot, as i was out of town.

no other equipment on my surge bar took damage.


thanks for your time and help.

p.s. will get photo up soon, but pdf is nice.

edit: i only use front left, front right, center, and sub out via LFE.
would like to test all them (dont know wher LFE , may know where rest is, would love to be told on all tho.), was going to finally get my last 2 speakers for 5.1 then this happens

[tibimakai]

Re: Need help, fixing onkyo tx sr507, bad channel, blown fuse.

I don't have experience with those receivers, only with the newer ones, but I would check all the components at that channel.
On the newer ones, the pre-amp section is on a vertical board, if yours is the same way, I would remove that board and go through all the components at that channel. Do the same thing on the main board, at that channel only.
You could just cut the legs of the final transistor legs, and see if everything start working.

[dobrykamil]

Re: Need help, fixing onkyo tx sr507, bad channel, blown fuse.

Based on my experience with Onkyo receivers, every single unit with blown final transistors has also had shorted Qs like Q6030,6040.Check emiter resistor R6100 and base resistors R6080, R6090, R6020, R6040. Look for dry joints in pre-amp part too. In many cases, I've seen blown C6040 capacitor - I always replace it as a precaution. Basically, if you don't replace all dodgy components in pre-amp, your final transistors will go pop again.