Screwed up my Crack upgrade

[flyfisher55]

Is it safe to turn the amp on without the ceramic 10W resistors?

[flyfisher55]

Turned amp on with 12AU7 after removing large board. Two LED's under 1B are still out. I'm going to need a bit of guidance doing the resistance test on the large board. As I said previously, "total newby" Sorry! 

[Paul Birkeland]

Yes, you can run the amp with no 6080 and no 3K resistors.  Yes to DC resistance, set it to the lowest range if your meter isn't auto ranging.

You'll want to do the same test for shorts on the transistors on the small board as well.  It is highly unusual to have that kind of failure from a slip at one of the outputs on the big board.

[flyfisher55]

DC VOLTS OA 68.2
                IA 233.6
                B A/B 0
                 IB 233.6
                 OB 82.4

[flyfisher55]

can you give me a little more detail as to how I should check the transistors? The meter does have auto range

[Paul Birkeland]

Set the meter to ohms, touch each pair of terminals with the meter probes.  If a pair of terminals reads a really low impedance (a couple of ohms), then the transistor is shorted.

[flyfisher55]

I'm a little confused as I see three pins on each transistor. When you say "pair" you're referring to the two outer pins on each individual transistor?

[Paul Birkeland]

There are 3 pins on each transistor, so there are 3 pairs of pins to measure:

1.  The DC resistance between the two outer pins.
2.  The DC resistance between the middle pin and one outer pin.
3.  The DC resistance between the middle pin and the other outer pin.

-PB

[flyfisher55]

These are my readings

QIB Outer two pins 0
R+C 35m
L+C 30m

Q2B Outer two pins 0
R+C 11
L+C 11

Q2A Outer two pins 26.5
R+C 16
L+C 0

QIA Outer 2 pins 0
R+C 35
L+C 30

[flyfisher55]

Large Board
 02A outer 2 pins 21.54
L+C 16.63
R+C 0

O2B outer 2 pins 21.43
L+C 16.59
R+C 0

Q1B outer 2 pins 52
L+C 52
R+C 1.1

Q1A outer 2 pins 0
L+C 21.62
R+C 21.23

[Paul Birkeland]

You have no units on the numbers you have.  When you write 21.54, is that 21.54 ohms or 21.54 megaohms?

[flyfisher55]

Meter shows m and ohm sign

[Paul Birkeland]

That's millions of ohms.  Your meter may also show "OL" which means "over limit", but is not 0.

[flyfisher55]

O.L not 0

[Paul Birkeland]

OK, so now that you know that, do any pairs of leads actually measure zero ohms?