Home Theater Power Supply Dissect

• Jul 4, 2017

• #1

GoldDot40

Senior Member

My home theater developed an issue where it would just "buzz" whenever I turned it on without playing the audio from the source. After doing some research on a few A/V forums, I felt the need to crack it open and explore.

I found the following, which was basically what I was looking for...I think. Anybody here able to confirm these 2 capacitors are fried?

If this turns out to be the problem, the fix is about $2 vs $100+ for a new power supply/amp.

 

• Jul 5, 2017

• #2

Nugefan

Senior Member

they look smoked to me , they have at least gotten really hot ....

 

• Jul 5, 2017

• #3

Rivershot

Senior Member

Busted a cap, or 2. Question is why?

 

• Jul 5, 2017

• #4

PappyHoel

Senior Member

Could have been lighting. I would just find a good used one or refurbished one to replace it, I wouldn't want to repair an older model (just me). Www.accessories4less.com is where I bought a refurb denon.

 

• Jul 6, 2017

• #5

S

SwampMoss

Senior Member

IF I'm not mistaken china tried to make a clone of the capacitors but was missing a key component they would prematurely fail. It could be something else causing them to burn out. The caps are cheap to replace and try.

 

• Jul 6, 2017

• #6

GA native

Senior Member

Them capacitors have been overloaded. Most likely from a lightening strike nearby.

A new capacitor is .30 cents. But if those capacitors got fried, it is likely that other parts are fried as well. And the dielectric gel oozing all over the circuit board just further complicates the troubleshooting. If the capacitors are that bad, I'd wager that the printed circuit is damaged as well.

I'd just scrap it and get a new receiver.

 

• Jul 6, 2017

• #7

660griz

Senior Member

GoldDot40 said:

My home theater developed an issue where it would just "buzz" whenever I turned it on without playing the audio from the source. After doing some research on a few A/V forums, I felt the need to crack it open and explore.

I found the following, which was basically what I was looking for...I think. Anybody here able to confirm these 2 capacitors are fried?

If this turns out to be the problem, the fix is about $2 vs $100+ for a new power supply/amp.

Click to expand...

If it is just the caps, you are good to go.
We had a rash of motherboards awhile back, everyone of them had a certain cap that would fail. Hopefully, you will get lucky and it was just their time to 'let the smoke out'.

 

• Jul 6, 2017

• #8

GoldDot40

Senior Member

After looking closely at every capacitor and diode on the circuit board, these are the only 2 showing evidence of overheating.

Found another A/V forum which had a few members with the exact same unit...doing the exact same thing mine was. One opened his and found this to be the issue. Soldered in some new caps and said his has been flawless ever since. The other members followed his lead with success. These are the same 2 caps that were fried in theirs too. Sounds like a bad batch of capacitors used in these particular units. I have 2 brand new ones ready to go...just ain't had the time.

 

• Jul 7, 2017

• #9

S

SwampMoss

Senior Member

How old is the unit? The bad electrolyte caps were used up until around 2007 if I'm not mistaken.

 

• Jul 7, 2017

• #10

GoldDot40

Senior Member

SwampMoss said:

How old is the unit? The bad electrolyte caps were used up until around 2007 if I'm not mistaken.

Click to expand...

Date of manufacture is Sept 2006...so you may very well have nailed it.

 

• Jul 7, 2017

• #11

NOYDB

BANNED

Since it is partialy fried you can't make it worse by attempting to replace the caps. If they work you are to the good. If they don't you were going to need to replace it anyways. Good luck.

 

• Jul 8, 2017

• #12

GoldDot40

Senior Member

NOYDB said:

Since it is partialy fried you can't make it worse by attempting to replace the caps. If they work you are to the good. If they don't you were going to need to replace it anyways. Good luck.

Click to expand...

We think alike. That is exactly my intentions. If it works good...if not...i have a reason to upgrade.

 

• Jul 22, 2017

• #13

GoldDot40

Senior Member

Finally got around to replacing those capacitors. Got less than. $8 in the entire fix...which includes a solder sucker pump I needed to help remove the solder to detach the caps from the circuit. Soldered the new ones in place, reassembled everything and plugged it all up. Works like new.

 

• Aug 1, 2017

• #14

S

SwampMoss

Senior Member

Good Deal