TIPS on Trouble Shooting

[MacL]

Hi All,
Just finished my Budgie SE amp build which sounded great the first 40 minutes. Then I blew a 1 amp SLO-BLO fuse. Replaced fuse and it instantly blew this time.
No apparent burnt/smoking parts. Don't know if this works-checked all resistors to see if they still had there values on meter-they seemed OK. Any generic tips on trouble shooting would be helpful. All caps appear good and new. I have built several projects in the past- and troubleshooting has always been challenging. Most times my projects don't die like this - if I have a problem it is usually a signal problem -Cliff jack wired wrong or something not grounded and I get noise.
Thanks All

[kheper]

Very generic tips:

Remove the tubes. Put a new fuse in. See if it blows.

Make sure that the driverboard has a solid solder ground connection to the chassis.

If the fuse does not blow, take voltage readings as specified in the manual.

Whenever a fuse of mine blew, something in the path of the B+ was hitting ground, intermittently. But, check the voltage path to the drivers, too.

[Shannon Parks]

First check the two diodes to see if one of them blew with your DMM (also looked for any burnt resistors). If both are OK, then see if you can replace the fuse and take voltages. Take the cathode voltages on all three tubes and the power supply voltages at J5-1, J5-2, J6-1 and R21.

Shannon