Onkyo-593 No power and now clicking sound

[Sisko]

Hi all!!

Ok just got a Onkyo SKW-593 sub woofer that has no power person told me that it smoked and that his GF let the volume full when she powered off the amp and when he came to turn it on the sub played but then suddenly smoke was coming out, didn't say from where. So opened it up and saw a resistor made of metal (pic) but can't see any writing on metal par so what ever was written on it was burnt. So I'm kinda stuck here with this. I did ask for a repair or schematics in the other group section and waiting for this but I hope someone here might lend me a hand to try and identify this resistor and on the board it is marked with this symbol; "W" yep a w just as if it was a fuse but it's not that soldered par has an R. Ok just looked it up on the microscope and I can't see any writings at all BUT I do see 3 bands one is thin and the other two are bigger and since its burnt the bands are black as you can see in the photo. So now what? any help with this would be very appreciated!!

UPDATE!!

Ok Replaced a few parts but now getting a "clicking sound" when powered on and yes I am plugged with a dim bulb thing. For now I know it's in "protection mode" did lift pin 12 VCC on the IRS2092 and two big caps (and other parts in the red section) and I get 0V BUT when it's clicking I get very faint voltage readings. So right now I have no idea where to look for. I did ESR on the 4 big caps and all checks out ok and did voltage test on the longest 2 caps but not getting voltage because of the clicking sound. Before changing the parts (3 parts pic) that weren't good it wasn't clicking at all but after it started to click. I'm trying to learn to fix electronics as much as I can but this one is a bit hard to find the problem but I'm asking you PLEASE no jokes or stupid answers. I have provided schem, parts changed and a pic of the section that is causing the problem. Any help would be very welcomed.

[madan1]

Clicking usually means that the smps can't boot.
Show on the schematics where is the "W" part.

[Sisko]

Clicking usually means that the smps can't boot.
Show on the schematics where is the "W" part.

Ok but what do I do from there?? and what is SMPS and where is it on the schem?

Thanks!! ;-)

[madan1]

SMPS = switching mode power supply, lot's of info out there if you are interested.
As I asked above - where was the burnt component in the schematics? If you can not locate it there, just post some good photos of the board (both sides) and point there the blown component(s).
Otherwise start with the standard things - check the mosfets q951 q952 for short in diode mode.
Check c954 c955 c963 c905 c902 c901 c912 c911 for short.

[Sisko]

SMPS = switching mode power supply, lot's of info out there if you are interested.
As I asked above - where was the burnt component in the schematics? If you can not locate it there, just post some good photos of the board (both sides) and point there the blown component(s).
Otherwise start with the standard things - check the mosfets q951 q952 for short in diode mode.
Check c954 c955 c963 c905 c902 c901 c912 c911 for short.

Ok here's the pics!! The big caps in pink have been checked with an ESR and they are good. The parts that I have changed are in blue. Hope this helps and THANKS for your help here!!!

Sisko

[madan1]

All those blue components are on the secondary side. Were they blown?

See above which components to check for short. Also check q901 c907. Check c963 out of the board for capacitance and esr.
Remove the white goo.

[Sisko]

All those blue components are on the secondary side. Were they blown?

See above which components to check for short. Also check q901 c907. Check c963 out of the board for capacitance and esr.
Remove the white goo.

Hi there

Ok changed the 2 caps (c963, c907) they were bad and the q901 I have already changed, checked q951 and q952 all ok.

Yes the 3 parts were blown (first message have pics with the 3 parts that weren't good, the q901 is there).

That white goo is hard to take off though!! BTW that "W" on the schem is it a waveform if I check it with an oscilloscope?

THANKS for your help with this!!!! I appreciate it very much!!

Sisko

[madan1]

" resistor and on the board it is marked with this symbol; "W"" <-- show the W resistor on the photos or the schematics.
So, if all replaced components were bad, this is no bueno. Most likely you gonna need to replace and IRS2092.
Confirm that there is no short on c954 c955 c963 c905 c902 c901 c912 c911 + c503 c432 c431 c451

p.s. if there is no short on that caps, try powering the unit without RFI4212H.

[Sisko]

" resistor and on the board it is marked with this symbol; "W"" <-- show the W resistor on the photos or the schematics.
So, if all replaced components were bad, this is no bueno. Most likely you gonna need to replace and IRS2092.
Confirm that there is no short on c954 c955 c963 c905 c902 c901 c912 c911 + c503 c432 c431 c451

p.s. if there is no short on that caps, try powering the unit without RFI4212H.

Hi there, Sorry for not updating this I'm doing this in my spare time now it's a rainy day I had the time to do all the cap test you said and I had to change some
so now all are ok. So now you want me to desolder RFI4212H, and by doing so what should I expect to happen? BTW I see test points on the board is there
any thing that this could help me?

I just wanted to say that this speaker turns on by itself when the sound system is turned on and what happened to have "blown" this bad is that
someone had forgotten that the speaker level was at full and she turned up the volume to full on the sound system and he said that he saw
smoke coming out (it was a fried resistor R542). Hopes this helps a bit.

THANKS!!!!

Sisko

[madan1]

... I had to change some so now all are ok.

what do you mean? At the moment we are not looking for bad caps. We are looking for shorted power rails. All listed caps are just easy access points to probe the rails. A capacitor out of specs will not cause such an issue, only a totally shorted cap would (apart from the cap near the smps IC, but given the blown components, it is not the issue)

So now you want me to desolder RFI4212H, and by doing so what should I expect to happen?

if the power supply boots, this would mean that RFI4212h has died again and/or q501 is also bad.

it was a fried resistor R542).

check C542 for short.

[Sisko]

QUOTE=madan1;n3741454] what do you mean? At the moment we are not looking for bad caps. We are looking for shorted power rails. All listed caps are just easy access points to probe the rails. A capacitor out of specs will not cause such an issue, only a totally shorted cap would (apart from the cap near the smps IC, but given the blown components, it is not the issue)


if the power supply boots, this would mean that RFI4212h has died again and/or q501 is also bad.


check C542 for short.

[/QUOTE]

Hi there!!

Ok for now I have never understood power rails and what to look for in a schem for this, yes I did try to look at YT vids but it's almost all laptop power rails and they have schem that shows where
they are, I have the schem for the subwoofer but they don't say where are the power rails. I don't fix electronics every day I do this now and then when I have the time so I can't learn all
that much when I don't have time to do this, I do have a normal job but I was always interested in fixing electronics since I was a kid but never got the time to do it often so I haven't learn
every thing. I took this sub thinking it could be just a blown fuse but I saw that burnt resistor so I saw it would be more complicated so hey I need to learn this "trouble shooting" for problems like this one.
This was something that I wanted to do as a job but at school I needed to be good in math and I wasn't so..... but I always had passion and desire to fix electronics and still have this "drive" for it.
So I'm sorry for not understanding you in some ways and I hope you understand me for this.

Ok power supply boots?? Ok you mean turns on, right? There isn't any power on light on the board BUT there is one in the front of the speaker that is unplugged.

Ok C542 no short. I didn't have time to recheck all the caps if they were shorted that you have mentioned earlier, will do it tomorrow.

Again THANKS and sorry if I don't understand what you mean sometimes.

Sisko