Technics 1210 problems!

[djruntime]

Hi,

I have a problem with my technics, the strobe light flashes on and off when the platter turns and there seems to be less torque. Do you think I should replace q1 (i have 27,27 and 36 volts off Q1)?


any help would great

Thanks

djruntime 🙂

 

[Netlist]

Hmm...what did the turntable drink? 🙂

35.8V on collector.
21.6V on base
21V on emitter
are the correct values.
27V is IMO too high.

I never encountered this problem. What happened just before?

/Hugo

 

[djruntime]

Hi,

I think I may have shorted something, was replacing the target light!

Just been doing some testing, i think q3 may have blown as i have 15v and 27 volts either side of r2. (also have 15 volts and 36volts either side of r1).

what do you think? do you think i may have damaged something else?

cheers

 

[Netlist]

What transistor# is Q1? 2SD389 or 2SD1265?
Depending I can post the detail of the PSU with corresponding voltages.
Apart from that, you have a good chance Q2 and Q3 are broken.

/Hugo

 

[djruntime]

Its 2SD1265 🙂

 

[djruntime]

Also got 0v at the 5v test point d3, i'm pretty convinced its q2 or q3 now.

 

[Netlist]

This might help in case you don't have the schematic.
Go for it, replace Q2, Q3.

 

[djruntime]

Thanks for that, I'm gonna try and get hold of q2 and q3 tomorrow and replace them.

Thanks alot for your help, i'll post my results when they are changed!

djruntime🙂

 

[djruntime]

Ok its looking better now, i've replaced q3 and q2, but have found that d3 has blown (ma4051mta) any ideas of where i can get these from?? or a suitable replacement?

cheers

djruntime🙂

 

[Netlist]

It's a standard zener, 5.1V 0.5W.

/Hugo

 

[djruntime]

Yup that done it, thanks alot for your help Hugo.

Regards

DjRuntime🙂

 

[Netlist]

You are most welcome.

/Hugo