National Stereo Radio Cassette Corder Repair guide.

[electronics_shamim]

Sirs,

Can any one help me tips for repair of National make Model No. mutilated form(not known), in which tape section works perfectly ok but radio section totally dead. I donot know exactly what to do, whether selector switch or Band selector switch or some other component gone bad, please advise .

Awaiting early reply,

regards,
Shamim_India.

[mvs sarma]

On the PCB or somewhere you are likely to find model number-

otherwise, a set of radio and tape recorder circuit books are sold by M/s BPB in india and they used to have a shop in MG rad Bangalore.

alternately, the local Panasonic service centre at bangalore(bangaluru now) can perhaps handle the item for you

Atleat you might put a photo how the item looks like to be able to know its model number.

Sarma

[electronics_shamim]

Dear Mr. SVS Sarma,

I am very much thankful to you for the reply. I am at one with you. Accordingly, I have searched everywhere on the pcb or at the backside, but in vain. However, I can tell you that the radio section used the following ICs and I have already downloaded and have with me the datasheet. What i need is the functionality of the whole operations of selector mode switch, which only i can have it on the whole schematic.

The Circuit uses the following ICs in radio section:

LA 1185 + LA1260
BA 1332
Main AF Ampl: uses BA5406

I doubt whether the selector switch (Radio/Tape/Sleep) or band switch (FM/MW/SW1/SW2) has gone bad.

Are you staying at Banglore?

Please also advise where could I have the same and in which book, as you specified which is available in BPB publications. Since, you also belong to India, can u please help me. However, I am ready to pay for all that.

Thanks and regards,

Shamim_India.
====

[pier]

People can try to make out the model number of ur stereo if u can post the picture of it . 

[electronics_shamim]

ok pier. I will surely post it shortly.

regards,
shamimim_india.
====

[mvs sarma]

Dear Mr. SVS Sarma,

I am very much thankful to you for the reply. I am at one with you. Accordingly, I have searched everywhere on the pcb or at the backside, but in vain. However, I can tell you that the radio section used the following ICs and I have already downloaded and have with me the datasheet. What i need is the functionality of the whole operations of selector mode switch, which only i can have it on the whole schematic.

The Circuit uses the following ICs in radio section:

LA 1185 + LA1260
BA 1332
Main AF Ampl: uses BA5406

I doubt whether the selector switch (Radio/Tape/Sleep) or band switch (FM/MW/SW1/SW2) has gone bad.

Are you staying at Banglore?

Please also advise where could I have the same and in which book, as you specified which is available in BPB publications. Since, you also belong to India, can u please help me. However, I am ready to pay for all that.

Thanks and regards,

Shamim_India.

Hi Shamim jee,

As you rightly told the wires comming from the radio-tape sleep switch can be traced and (thinking that battery is switched) the radio position wire coud have been wrongly placed by any other service or by the owner- by mistake. while the sleep wire will go to the Tape motor. 

So I feel if you trace with a Multimeter the voltage on the Vcc pin of radio IC wet ground- and see the correct location of the wire coming from the radio-tape-sleep switch.

In case a flat cable is hand wired or plugged from the switch concerned, --there may be a wire loose conn or print break just below the concerned wire.

we may have to handle the situation coolly by considering a  nearest comparable schematic--
now that you have told the ICs used let me see--

sir appearantly , how old is the 2 IN one?
you cam mail me also
Sarma

====

[mvs sarma]

Dear Mr. SVS Sarma,

I am very much thankful to you for the reply. I am at one with you. Accordingly, I have searched everywhere on the pcb or at the backside, but in vain. However, I can tell you that the radio section used the following ICs and I have already downloaded and have with me the datasheet. What i need is the functionality of the whole operations of selector mode switch, which only i can have it on the whole schematic.

The Circuit uses the following ICs in radio section:

LA 1185 + LA1260
BA 1332
Main AF Ampl: uses BA5406

I doubt whether the selector switch (Radio/Tape/Sleep) or band switch (FM/MW/SW1/SW2) has gone bad.

Are you staying at Banglore?

Please also advise where could I have the same and in which book, as you specified which is available in BPB publications. Since, you also belong to India, can u please help me. However, I am ready to pay for all that.

Thanks and regards,

Shamim_India.
====

please see the photo whether RX 5030 tallies

Sarma
at Hyderabad

[electronics_shamim]

Dear Mr. Sarma,

Thanks for the efforts sending the photo of a 2-in-1, but not the one which I meant. It is black in colour and slightly longer (horizontally) and height is short. I will get the photo shortly. Donn't worry please. Bear with me for the time being.


regards,
shamim