luxman l-450 output transistors

[maciek]

My luxman l-450 keeps blowing fuses,I searched net and found that it may be output transistors,anybody knows any source for sk a1196,sk c2581,t c2238,t a968,output transistors,or other suggestions for solution?thanks for help.

 

[avionic]

Try here http://www.bdent.com/

drop the sk & t..then put a 2S as a prefix 2SA1196,2SC2581 etc..

BTW shot gunning parts isn't a very good way to fix a problem..and usually ends up worst than what it was..

 

[maciek]

Avionic thanks

Thanks for hint about transistors,do you think putting new transistors isnt gonna help? What may be reason for blowing fuses?

 

[jwalker]

Thanks for hint about transistors,do you think putting new transistors isnt gonna help? What may be reason for blowing fuses?

The problem with replacing parts with no clear direction is that you may wipe out any clues that can tell you what the real problem is. Shorted transistors can cause blown fuses, but so can a shorted transformer, a shorted cap, etc...

If you truly believe that the output transistors are the problem, start by checking those transistors for shorts in circuit from the collector to emitter in the case these are BJT's. There are other tests you can run on suspect transistors such as looking at the base-emitter and base-collector junctions. Look on the web for some guidance.

 

[ryuuoh]

When the outputs go, they frequently take out upstream components. As jwalker said, check your outputs for shorts, then check the emitter resistors for opens, and the parts in the driver stage for problems. Tools to have are an multimeter with diode check function, screw driver, soldering equipment, service manual.
Good luck! Those are nice amps.

 

[chuckk22]

A Comment

Hi!
For what its worth, what I do is use my DVM to check transistors. It has a diode checker function. I check accross base/emitter junction of each suspect transistor. It should read around 0.6 to 0.7V in one direction and nothing or a much high voltage in the other direction. I also test the base/collector junction (normally reverse biased).

When troubleshooting, it is essential to try and find the section or area where the trouble lies. There are many "tricks" to use in doing this, such as temportarily unsoldering a resisor etc. If you have a schematic and you carefully follow the circuit flow you should be able to nail down the problem area.

Good luck!

 

[maciek]

Thank you guys for ideas,let you know if found problem.