Harman-Kardon Festival3 Repair need replacement part....

[30W]

My father asked me if I could repair his old record player for him, so
of course I took up the challenge. I found two transistors shorted
out. There is no part reference on the board (Q1 etc.) just numbers
10,11,12 for the first transistor. And 13,14,15 for the second
transistor.

The part it self says this on it:

M044 (M looks like the motorola M)
26932

Google turned up nothing informative. Is there a replacemnet that can
be used instead of the M044?


Thanks alot for any help!!!!!!!!!!!

 

[TimPerry]

My father asked me if I could repair his old record player for him, so
of course I took up the challenge. I found two transistors shorted
out. There is no part reference on the board (Q1 etc.) just numbers
10,11,12 for the first transistor. And 13,14,15 for the second
transistor.

The part it self says this on it:

M044 (M looks like the motorola M)
26932

Google turned up nothing informative. Is there a replacemnet that can
be used instead of the M044?


Thanks alot for any help!!!!!!!!!!!

what stage were they in? small signal or power output?

if its small signal its likely that a wide variety of replacements would
work.
if its NPN try a NTE 123A

 

[30W]

Thanks for the quick reply I have no way of telling what role the
transistor is playing. There are 5 transistors screwed into the back
metal plate for a heatsink. There is one small one and 2 medium size
ones and 2bigger ones. The medium ones are the bad ones. There is no
marking on the board to identify it as NPN or PNP, all that is on the
board are the usual BCE. You have any idea if its a power or small
signal?

again thatnks alot!!

 

[NSM]

Thanks for the quick reply I have no way of telling what role the
transistor is playing. There are 5 transistors screwed into the back
metal plate for a heatsink. There is one small one and 2 medium size
ones and 2bigger ones. The medium ones are the bad ones. There is no
marking on the board to identify it as NPN or PNP, all that is on the
board are the usual BCE. You have any idea if its a power or small
signal?

The size of the body of the transistor is a good guide. Look for TO-3 TO-220
and you'll find pictures of various sizes.
http://www.mospec.com.tw/package.htm

N

 

[30W]

Its not a TO-3, its closer to a TO-3P but smaller. Here is a bad
picture of the transistor. Sorry for the blurryness but that was the
best shot of the 5 I took. The bigger one is a TO3P and the 2 smaller
ones are the bad ones im trying to replace.

http://members.aol.com/habibz711/bad.jpg

Thanks again!!!

 

[NSM]

Its not a TO-3, its closer to a TO-3P but smaller. Here is a bad
picture of the transistor. Sorry for the blurryness but that was the
best shot of the 5 I took. The bigger one is a TO3P and the 2 smaller
ones are the bad ones im trying to replace.

Looks similar to a TO-220 but for higher power. Do you have a parts supplier
locally?

N

 

[30W]

Yeah there is a supplier about 20 mins away from here. They are
probably closed for the weekend now. Or there is a radio shack about 5
mins away. But radio shack sucks nowadays.

Is there a way I can tell if its NPN or PNP?

thanks!

 

[NSM]

Forget Radio Shack. See if the supplier can cross reference the part or
suggest a similar one. It's audio so not too critical.

Measure the voltage from collector to emitter. For NPN the collector will be
positive to the emitter. That's very likely to be what they are.

N

 

[30W]

Actually the collector is shorted to the emitter and there are no
other ones on the board for me to try that test on.

Ill try and give them a call on Monday and see what they say.

Thanks alot for your help NSM

 

[TimPerry]

Actually the collector is shorted to the emitter and there are no
other ones on the board for me to try that test on.

measure the voltage at the point the transistors were removed from with the
unit turned on (if you can do so safely).