Replacement for transistor in MAC4100 Power Supply

[hirscwi]

I am repairing the regulated power supply in a MAC4100. Two transistors and a zener were destroyed in a short to the +18V supply.

Q601 was as FT3055 that I will replace with TIP 3055

D606 is a 1N4739A that I will replace with the same.

But Q602 is the problem. It is marked with a Motorola symbol and the numbers "821 171" Using my DC55 it measures Hfe = 67(test current 2.5mA) and Vbe = .72V (test current 4.68) It is McIntosh part number 132-171.

I assume it can be replaced with a common transistor but I'm not astute enough to be able to make the replacement. Can anyone help?

Thank you.

 

[eedork]

Hey Bill -

Check this thread for a sub for McIntosh 132-171:

http://audiokarma.org/forums/index.php?threads/transistor-substitutions.422468/#post-5395502

-Matt

 

[hirscwi]

Thanks, Matt.

 

[hirscwi]

Looks like it's MPSA05 to replace the NPN transistor. Thanks.

 

[clinic-audio]

Hello
yes 132-171 is a MPSA05

 

[hirscwi]

Hello
yes 132-171 is a MPSA05

Thank you.