Bang and Olufsen Beolab Beovox Penta Amplifier repair attempt part 1

this one is a standalone amplifier model 1723 that is why it looks a little bit different in the top mounting, but the inside amplifier is the same as a regular type 6603. C18 C20 220uF 40V tottally shorted ! its in the idle supply, and powerfull 1.6MHz oscillations overloading the power amp.
I call this part 1, since it is on PAUSE due to output transistor and bias parts, need more parts and more time.. lets see if that is ever going to happen.
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#teardown
#bangandolufsen
#poweramplifier
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I use auto generated subs, so if you find errors worth fixing, please comment with the time in the video you saw the error, i will be happy to fix it. This also apply to the Danish version.
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(Thanks to all my Sponsors / Traders / Swappers / Sellers / Buyers, without your support and constant flow of cool items in/out, none of this would be possible)

[@michaelc821]

Looks like someone has had it apart already.

[@carloca71]

Interesting audio gear and a very nice repair attempt dude, wold like to see an autopsy of the failed caps, how they look inside, quite curious about the failure. Have a great 2023!

[@TeardownOZ2CPU]

i had the idea too, but forgot about it, and simply thrown the caps out, sorry about that.

[@carloca71]

@@TeardownOZ2CPU No problems dude.

[@enriquealvarez3157]

I have a pair of Penta Model speakers 6603 I think it's the Penta 1. My question is, can it be connected directly to a sansui or onkyo sound amplifier through an RCA cable? Wouldn't it damage the lower amplifier that the speakers come with?

[@TeardownOZ2CPU]

sure, they should be able to do that

[@michaelc821]

Guessing is he

[@michaelc821]

If people want through away, their choice.

[@high-endvintagelover5779]

Er du dansker 😅🇩🇰??

[@TeardownOZ2CPU]

har da et dansk pas og et dansk radio amatør kalde signal oz2cpu :-)

[@PedjoGT]

Hmmm...one of my Penta 2 amps power up itself without signal every few minutes!!?? Power is set up in Auto mode....what you think?

[@AAgunner]

Maybe it's picking up a rouge signal from another device?

[@PedjoGT]

@@AAgunner hmm...i have another problem....cracking sound when it is cold...bass membrane go with cracking out...amp have poer and normal sound but this anomaly got me mad....i changed all small capacitors from board but crasking and wooshing remains

[@AAgunner]

@@PedjoGT I wish I could help, but my Penta's are without amps. You could remove the amps and try to connect them to some other speakers and see if they also crack?

[@PedjoGT]

@@AAgunner Tried and the same issue

[@AAgunner]

@@PedjoGT Hmm yeah sounds like it's in the amp. If you have the money, I would just bring it to someone that fixes older amplifiers for a living. Could just be a loose wire if you're lucky.
A guitar amp builder might also be able to help you out. The measuring tools that they use are too expensive for one time use.