Kedvey lalkók! Lenne egy ilyen hangfalpár,amin elporladtak a peremek,újra szeretném peremezni nos az lenne a kérdésem hogy Sal peremet érdemes rá tenni? Vagy rendeljek a H2000 től peremet,azért kérdezem a H2000 peremeket nem igazán ismerem, és ezért nem tudom eldönteni hogy melyik perem a tarósabb.. T:Zsolt.
Bom dia amigos, estou com um reviver AVR3.0 cujo FM não funciona, já troquei o IC de fm, ajustei quadratura, troquei filtros cerâmicos, já medi capacitores cerâmicos, medi alimentações no ci FI de fm mas não funciona o rádio tanto am como fm nem chiado !
Obrigado
Sziasztok!
Vaz egy SONY hifitorony tipusa:HCD-R550. Az a jelenség,hogy ha bekapcsolom,PUSH-POWER-PROTECT-felirat villog a kijelzőn! Valamit matattak a hanfalkábeleknél kint,lehet összezárták! Talán végfokos lenne? és ezt jelzi ez a kiirás? Stk 407-090 van benne.lekötöttem a végfok összes lábát,és akkor is ez a felirat van jelen! Valmi tipp aki már csinált ilyent??
Köszi!
Üdv:Sparco
This one had been sitting in a barn for years. Powered it up and the large power transistors on the heat sink would get hot
after a time....and the heat sink would also get quite hot. Speakers sounded like they had some DC on them....with a loud thump
Found the manual on Hi-Fi engine,
[
http://www.mediafire.com/file/b8mlsu7q3pz0bvf/hfe_nad_3140_service.pdf/file ]
and saw a video on youtube saying lots of capacitors dry out
due to their locations near resistors that get very hot, I guess sorta a poor
design. Went in and recapped almost the entire
product save for the (4) large 50V PS caps which appear to check ok.None of
the high power or driver transistors
mounted to the main heat sink were shorted..
Powered on but no audio, and noticed the fuses to Bridge D805 were melted open.
I believe they were ok before.
Replaced them and they started to light up like fiilaments, so shut down,
removed the bridge D805, then checked it, its ok.
There is about a 16 ohm short on the + / - lands where the bridge was. It
seems like something I did maybe is causing this,
like a capacitor in backwards, which I am doing alot of lately for some
reason.
Turns out, yep I put C805 (470/ 63) In backwards ! Capacitor still checks
ok, so will re-use it.
Short is still there though Im guessing R803 is adding in 5.6 ohms or so,
that means theres a 10 ohm short someplace. Q801, 802 arent reading short,
and looks like this becomes a +43V ps feed.
Any ideas out there on what to check next? I am guessing this cap in
backwards caused the voltage applied to a component to be
reverse and its shorted. Or would this be normal with a reversed cap installed,
and putting it in right would be how to fix it?
Steve Hearns
Technotronic Dimensions [USA]
WWW.TECHNOTRONIC-DIMENSIONS.COM