Sure do love these little testers!

[Chevboy0167]

http://www.ebay.com/itm/12864-Mega3...803031&hash=item2cc4622763:g:~-IAAOSwcNxZjLYA

Have a Connex 3400HP here that had a direct short to pc ground. Blew fuses in both sides of my power cord or trip the power supply the first 2 times tried to power up. Take covers off to see someone soldered a small trans former on top of the stock transformer already soldered to pc board, with an axial electrolytic to neg power jack terminal. Other lead of added xformer was to pos side of power jack. Hot lead from main PC board was removed from power jack and soldered to added xformer where the extra cap was added. Now looking at all this, the added xformer looked funny... as in it has gotten hot and melted/deformed. Only thing that comes to mind is this was added for an extra filter circuit maybe? Didn't care, removed it all. Found 2SB827 shorted, 2SA1869 open and traced it all back to driver and 1 final bad. This rig uses IRF520 for driver and both finals. Point here is this little tester showed me the difference in the failures compared to the good final. Time to order parts. I will try to add some pics here.....

 

[Chevboy0167]

 

[Chevboy0167]

How a good FET reads.





The driver..




And the final that is blown..

 

[Chevboy0167]

Sorry, the driver should show..

 

[melaza]

http://www.ebay.com/itm/12864-Mega3...803031&hash=item2cc4622763:g:~-IAAOSwcNxZjLYA

Have a Connex 3400HP here that had a direct short to pc ground. Blew fuses in both sides of my power cord or trip the power supply the first 2 times tried to power up. Take covers off to see someone soldered a small trans former on top of the stock transformer already soldered to pc board, with an axial electrolytic to neg power jack terminal. Other lead of added xformer was to pos side of power jack. Hot lead from main PC board was removed from power jack and soldered to added xformer where the extra cap was added. Now looking at all this, the added xformer looked funny... as in it has gotten hot and melted/deformed. Only thing that comes to mind is this was added for an extra filter circuit maybe? Didn't care, removed it all. Found 2SB827 shorted, 2SA1869 open and traced it all back to driver and 1 final bad. This rig uses IRF520 for driver and both finals. Point here is this little tester showed me the difference in the failures compared to the good final. Time to order parts. I will try to add some pics here.....

Autozone has the right tool!!

 

[Robb]

Driver is blown.

 

[Limeybastard]

I also like that those "pill" testers that show what wattage they are capable of.

 

[Tallman]

I have one of those and it is a good quick way to verify a bad part. I have a component tester built in to my oscilloscope and it shows a bad transistor very clearly.
This trace below is made from the ms1051 from RMI Italy.
Check out the other wave forms in my album, all of those transistors were never installed or soldered on. I learned to test those before installing in the amps.

 

[Onelasttime]

I also like that those "pill" testers that show what wattage they are capable of.

It is not showing the wattage it is capable of that is beta gain or hfe and has little to no bearing on wattage output not in the way you are thinking. A 2SC2879 with a beta gain of 30 and one with a beta gain of 85 might likely produce the exact same output power in circuit. That does not mean beta does not matter.

 

[LeapFrog]

I agree Chevyboy0167, looks like a choke and extra filtering capacitor (maybe they ran a dirty power supply or had noise issues being mobile). I'm glad you are getting the rig sorted out!