CurtPalme.com Home Theater Forum

[PaulB]

The Vertical Board in my 9500 has started buzzing

Any way to find exactly which component is the guilty party? I tried a stethescope (a tip picked up from Athanasios) but I just can't seem to pin-point the exact spot for some reason. I tried touching the caps but didn't make a difference (hoped that touching it may stop it buzzing but its an elusive little devil and may not have been a cap).

Everything works fine but the damn buzz is louder that the pj itself and its bugging me now!

EDIT - Found this at the other place http://archive.avsforum.com/avs-vb/showthread.php?s=7192441eecb83c9c9d5f2332c255558c&threadid=471479&highlight=buzzing and here http://archive.avsforum.com/avs-vb/showthread.php?s=7192441eecb83c9c9d5f2332c255558c&threadid=347336&highlight=buzzing

I've just changed the caps (well, a while ago now) worth changing again do you think?

[Nashou66]

Hmmmm, I have always heard of the famous VDM buzz but have not experienced it on my three machines. I read through both threads lou linked and would do as Mike suggested for all three caps and also look at those transistors up on the heat sink. One may be going south or the Isolation strip behind it has a crack and its buzzing to the aluminum.

Athanasios

[Tim in Phoenix]

Hello


Be sure to use 105^C replacements, and apply some hot melt glue to them after reassembling.


.

[Ohmess]

Tim -- what is the purpose for the hot melt glue?

[Nashou66]

The Hot glue holds them together and puts a dampening effect to stop and resonant harmonics between them. It's a mechanical bond of the three group of caps to absorb the Buzz from what I understand.

Athanasios

[PaulB]

Thanks for the advice guys, will look in to it further.

[Ohmess]

How much have folks used hot glue on their modified boards? I have not used any.

There was a lot of it on my LVPS, but I did not apply any to the replacement caps.