Hello everyone,
I've this speaker model:
RCF art 415-A.
The power supply is faulty, no votltage out to the amplifier.
The Mosfets are blown. I've changed the mosfets and it's driver, and still have a problem.
I tried to switch on but only one of the mosfets gets hot (the one which switches the 310. There are 2 of them - Mos5 in the scheme).
Obviously I turned it off.
1) What causes it to heat?
2) Testing the VCC of the LMC555, it's only 2.7V. When taking it out of the circuit, it's 12VDC! What makes the voltage to drop. Where does the supply of the LMC555 come from? The VCC of the 555 should be around 10V, as compared with a good card.
I've changed the 555, but the problem remained. I've checked the components around, resistors and capacitors, and transistors, and seem to be OK.
4) The VCC of the Mosfet driver is 10V, but should be 12V if compared with a good card.
3) Could the trafo be damaged? Are these parts reliable or may blow up?
4) What is the purpose of the optocoupler in the circuit?
I would really appreciate any help.
I didn't find the 100% schemes for this RCF (400), but found a very similar one (The 600 version).
name and a link here to download the pdf.
DigiPRO600B
https://elektrotanya.com/db-technologies_digipro600b_sch.pdf/download.html
Regards and many thanks
Sziasztok!
Keresek 3db relét a fenti ARM-hez.
Üdv SuPeti
I already replaced the TDA 2030A audio output transistor and the sound returned but it is very noisy I didn't find any other faulty components, I suspect it's the speaker that burned out. The problem is that I don't have another speaker to test here
Üdv Mesterek!
A fent említett gép mindkét kazetta része hibás.
Rajz a Tanyáról megvan.
Viszont talán a vakságom az oka , de a rajzon nem találom a magnó részben lévő 1-1 fotodiódát.
Minkét rész kettős diódának szakadt a fénykibocsátó része, fény érzékelő része jó.
Magán a diódán sincs semmi feltüntetve.Talán 3x2mm lehet és 4 kivezetése van.
Fotóaparátom megállt.
Ismeri valaki ezt a masinát , vagy a diódát?
Valami hasonló kettős dióda beszerezhető?
Mi a pontos megnevezése.
Előre köszönve a segítséget.
Öreg T.