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Akai AA-910DB

yashoda rohana's picture

I bought an Akai AA-910DB earlier this Year from a junk yard it has some rust in it due to the rain which had got into the machine. then I brought it home and found out it works strongly the FM is good but when I switch it to tape monitor it makes a huge noise and I can't hear anything from that side.
I checked all the transistor with no luck because all of them are erased and I can't trace any of them.
Can anyone please help me with a circuit diagram or a manual.

Thank you.



karodimitrov's picture

Re: Akai AA-910DB

Will be good to clean well selector switch.Then check or replace the caps.I doubt the problem is in transistors.This yields in poor connection in some of switches.And no schematic...Look at this one:
https://www.hifiengine.com/manual_library/akai/aa-920.shtml
I think they are similar like parts and like years.The difference is that you have a dolby on your Akai.
Thing-parts in preamp are similar.

yashoda rohana's picture

Re: Akai AA-910DB

Thanks for the help and I will check the caps and the switches. I also think the problem is in the dolby side transistors.

karodimitrov's picture

Re: Akai AA-910DB

In older models switches are silver or silver plated and they often oxidized. Soon I had a similar problem with an old tube radio The problem was that all keys were dirty and oxidized.That's why I think that your problem is there.Try to snaps quickly the selector switch a few times - sometimes helps a little if there is an improvement - focus yourself there.

karodimitrov's picture

Re: Akai AA-910DB

Transistors - leave them for dessert.:)

yashoda rohana's picture

Re: Akai AA-910DB

I completely disassembled the switches and cleaned everything including the selector and the tape monitor switches but still I get the noise when I am in tape monitor.

karodimitrov's picture

Re: Akai AA-910DB

It's difficult without scheme.Check the caps.

yashoda rohana's picture

Re: Akai AA-910DB

True, It's very difficult to find some Transistors without the schematic and I checked the caps they seemed to be fine. Today I took out some Transistors and put them under a bright light and figured out some of them except for 4 transistors that are on the dolby side. Guess what the noise reduced a bit but still it is hard to hear from the tape monitor. The dolby FM & Aux side works even better now.

I think the problem is in those 4 transistors but I can't figure out the numbers of them because they are completely gone.

karodimitrov's picture

Re: Akai AA-910DB

Look here:
https://www.hifiengine.com/manual_library/akai/4000db.shtml
look at his schematic of Dolby-page 53.Can be useful for you. Dolby is Dolby and it is made in the same years.
2SC458,2SK30A...Try it.

karodimitrov's picture

Re: Akai AA-910DB

I wanted to say that the element base of Akai in those years was similar (transistors,capacitors etc)