CR-1020 Service advice please

[62sunbeam]

I'm debating DIY the service of my CR-1020 including any service bulletins and replacement of any other components you all recommend.

Any advice, recommendations and information is greatly appreciated.

Thanks

Eric

 

[avionic]

No service bulletins for the 1020. Only 2020's that I'm aware of.
Ocassional popping noises are most likely transistors.

 

[merrylander]

What Dave says is correct, however it does not hurt to at least check the value of the two 22 ohm fusistors on the vertical power board. The two 2SD234 25 volt regulator transistors are adequate for the current draw of the 1020 and need not be replaced.

 

[62sunbeam]

No service bulletins for the 1020. Only 2020's that I'm aware of.
Ocassional popping noises are most likely transistors.

Which ones and how do I test them?

Thanks

Eric

 

[avionic]

Which ones and how do I test them?

Thanks

Eric

Ahh..Finding noisy transistors..Its a bitch!. Sometimes you can locate them with either a heatgun or can of freeze spray. It really helps if there acting up constantly. Really difficult if it only pops once in a while. Transistor checkers will not usually reveal any problems. Swapping out the transistor is the only sure thing. If you find any 2SC458's replace'm with 2SC2240's or KSC1845's or equivilent replacement. 458's are well known noise makers.

 

[merrylander]

You can at least isolate the problem transistors by setting the coupler switch on the rear panel to OPEN. If it still pops thhe problem is in the power amps, otherwise it is in either the tone control board or tuner board. Next step is ti switch to tape monitor, still get pops pretty sure it is in the tone control board.