Akai AA 1150 connection problems

[Nazzote]

Hello, as I said in my intro to the forum I bought an Akai AA 1150 a few weeks later. It has some problems with it, first I'll post some pics of my receiver then some questions, thanks!

PROBLEM n°1
I have a cable flying around and I need to know where to connect it to... here is a part of the schematic (which I don't understand).

At the bottom it's a number 3 thats the wire I have flying around. I don't know what C903 and C902 means or why it says VLT...

That's the first and most easy problem to solve (I think it goes attached to the wire of one of the filter caps? If its that the case which one?)


PROBLEM n°2

It seems that the previous owner have the originals filter caps replaced with these 4 horrible caps... (4700uf 63v). I think it would be better if I replaced those horrible horrible capacitors with ones of 10000uf 50v. Is the wiring okay? What is that tiny cap above those two big blue ones? If I replace those do I still need that tiny devilish cap?


PROBLEM n°3

What are those two brown cables? They were welded to the pins 9 - 10. What do they do?

PROBLEM nº4

What is that black thing attached to the resistance? And why is there a resistance????


PROBLEM nº5
I don't think this is a problem but I need some advice about how can I test this with my multimeter and which kind of grease should I use.

PROBLEM nº6

This selector and the one from left up (source and selector) are way to difficult to change they are kind of stuck... What can I put to clean them and make them move more easily?


PROBLEM nº7

Which replacement should I use?


PROBLEM nº8

What should I say when I take the transformer to be rewired? I mean... If I give them the transformer they can do it exactly as it was before it burnt? Or should give them some specs?





Well... those are my problems for now... I'll appreciate every little or big effort you could make to help me get this thing operational. Everyday I'm learning more and more about electronic from youtube (and now here) and I really like it (I read the thread "Amplifier Sensitivity, Decibels, and You!" and it solve some questions I have had in my head for a long time).


Manual: http://www.hifiengine.com/hfe_downloads/index.php?akai/akai_aa-1135_1150_service.pdf

 

[cademan]

I'll try to answer your first question regarding what is VLT. I believe that it is pertaining to the wire color as being VioLeT.

Your brown cables are probably (but not sure) the preamps inputs coming off of the AM/FM/AUX selector switch.

Unless they are shorted, the capacitors are probably ok including the small one you mentioned. It looks like someone just added extra capacitance which is never a bad thing. C902 etc is where the letter "C" simply means Capacitor. R means resistor, Q means transistor.

Your so called problem #5 might not be a problem at all. It looks like the output transistors which are mounted to a heat sink to help dissipate heat. You don't have to remove them to test them and if they do test ok, leave 'em alone!

The black thing on that resistor looks to be a piece of plastic to prevent any possible grounding out. Is the power transformer really smoked? Doesn't look like it to me. If it is bad, a replacement could be found but the term "rewound" refers to a professional actually rewinding the entire transformer, including all voltage taps and current loading.

I'm not a member of hi fi engine so I can't see the schematic. People don't seem to realize that you simply cannot post the schematics from hi fi engine without being a member. The website won't let you.

Others will chime in as I am still pondering and studying the other problems.

 

[mrflex65]

This unit is full of soot like it was in a fire! Did the power tranny do this?

 

[Nazzote]

I'll try to answer your first question regarding what is VLT. I believe that it is pertaining to the wire color as being VioLeT.

Your brown cables are probably (but not sure) the preamps inputs coming off of the AM/FM/AUX selector switch.

Unless they are shorted, the capacitors are probably ok including the small one you mentioned. It looks like someone just added extra capacitance which is never a bad thing. C902 etc is where the letter "C" simply means Capacitor. R means resistor, Q means transistor.

Your so called problem #5 might not be a problem at all. It looks like the output transistors which are mounted to a heat sink to help dissipate heat. You don't have to remove them to test them and if they do test ok, leave 'em alone!

The black thing on that resistor looks to be a piece of plastic to prevent any possible grounding out. Is the power transformer really smoked? Doesn't look like it to me. If it is bad, a replacement could be found but the term "rewound" refers to a professional actually rewinding the entire transformer, including all voltage taps and current loading.

I'm not a member of hi fi engine so I can't see the schematic. People don't seem to realize that you simply cannot post the schematics from hi fi engine without being a member. The website won't let you.

Others will chime in as I am still pondering and studying the other problems.

Thanks for the help, I'm not very convinced about the brown cables... they are different from the rest of the cables, and they were weld to the pins when all the other cables were screwed to the pins (sorry for bad english). Now that you mention it was pretty obvious that VLT means Violet...

Capacitor 902? what is the meaning of the number?

Happy if they are okay, but how can I test them? I mean I saw a video where you have to put the multimeter in continuity and according to the schematics you get if they are okay or don't. I don't know if I made myself clear.

I'm gonna upload the schematics to a different server where you can reach it with out having to be a member, sorry!

Thanks again!


LINK: https://drive.google.com/file/d/0B_lqV6MIFLkVN09jRWRlVUxwWjA/view

Edit: I think the power transformer is really smoked... it has the smell and it's black inside. If there's a way to test it with a multimeter please let me know.

 

[Nazzote]

This unit is full of soot like it was in a fire! Did the power tranny do this?

I don't know... maybe it was in a family full of smokers? The power tranny is the power source, right?

 

[cademan]

C902 is just the location of the capacitors on the schematic in comparison to where they are on the boards. For example, if a unit has 10 capacitors, they would be labeled as something like C1, C2, C3, all the way to C10. These are not the capacitors values.

 

[Nazzote]

C902 is just the location of the capacitors on the schematic in comparison to where they are on the boards. For example, if a unit has 10 capacitors, they would be labeled as something like C1, C2, C3, all the way to C10. These are not the capacitors values.

Oh okay... where can I find the capacitor values?

 

[cademan]

A lot of schematics show the values but some don't so if they are not listed, most of the time, they are imprinted on the capacitors themselves.

 

[Nazzote]

Update:

Problems number 1, 2, 5, 7 and 8 solved!

Thanks!