First Time Crack Builder Need Assistance [solved]

[prtuc2]

I just take the top of the TIP50, the underside is a little hard to take.

TIP 50 closer to the octa-socket:
Top resistor          OL
Mid resistor          0 ohms
Low resistor        600k ohms

TIP 50 closer to the A-socket
Top resistor        500k ohms       
Mid resistor          >1000k ohms
Low resistor        OL

 

[Paul Birkeland]

I'd snap a photo of the bottom of the larger PCB.

For some reason, when activated, that board is allowing excessive current draw.

 

[prtuc2]

Sorry I know is hard to see with that pictures, that is the best I got for now.  I will upload some more if I get get better pictures.

 

[Paul Birkeland]

There's a fair amount of extra solder on the bottom there.  It wouldn't be surprising if one of the 2N2222A's had two pins sorted together.

 

[prtuc2]

I resolder the 2N2222A on both side





I got the same resistance value as before.

 

[prtuc2]

Any inputs?

 

[Paul Birkeland]

I would suspect that there was a short circuit present here.

In all likelihood, replacing the four transistors on that board would likely be helpful.

-PB

 

[prtuc2]

Is it possible to get it from bottlehead?  I don't want to order the wrong parts and more troubles.

And I already re-solder the back PCB board as you see in the previous post with the two PCB board pictures.

 

[Paul Birkeland]

Sure, you can contact replacementparts(At)Bottlehead(doht)com

 

[prtuc2]

I just contact bottlehead for parts replacement for 2 of the 2N2222A transistors and the 2 TIP-50 transistors on the large PCB if that is correct? 

 

[Paul Birkeland]

That should do the trick.

-PB

 

[prtuc2]

Is this what a blown fuse looks like?


The amp won't power on at all, the picture doesn't show very clear.  There is a streak of dot silver line along the side of the fuse.

 

[Paul Birkeland]

You can measure the resistance of the fuse with your meter.  A blow fuse will be over the limit that your meter can measure, a good fuse will present a low resistance.

 

[prtuc2]

All my resistance values are way above normal.  Only a few terminals are within limit.

Terminal 1    above 3000k ohms
Terminal 2    800k ohms
Terminal 3    0
Terminal 4    5000k ohms
.... etc..

Except Terminal 6 and Terminal 10, most of the values are way above the values of the instruction manual.

 

[Paul Birkeland]

Can you provide an example of a resistance that's problematic?  Your report of terminals 1-4 look spot on. 

 

[prtuc2]

Terminal 1        3500k ohms
Terminal 2        1000k ohms
Terminal 3        0
Terminal 4        1000k ohms
Terminal 5        3500k ohms
Terminal 6        2.494k ohms
Terminal 7        0        <<<< suppose to be 2.9k ohms?
Terminal 8        0
Terminal 9        OL      <<<< suppose to be 2.9k ohms?
Terminal 10      2.494k ohms
Terminal 12      0
Terminal 13      1000k ohms
Terminal 14      0
Terminal 20      0
Terminal 22      0

B3                    0      << suppose to be 2.9k ohms on the crack not sure on the sb upgrade is the same values
B6                    OL    << suppose to be 2.9k ohms

RCA ground lug: 0
Center pin:        100 ohms

 

[Paul Birkeland]

Does this Crack have a Speedball installed?

 

[prtuc2]

Yes, this is with the speedball upgrade install resistance values.  As I double check the soldering joint, so far no luck.  I will continue to check on the joint connection.

 

[Paul Birkeland]

If the Crack was working pre-Speedball, then there are no resistance checks to do after installing the Speedball (as indicated by the manual).

If you started with a dysfunctional Crack and installed a Speedball, you will need to remove the Speedball and remedy the original build first.

-PB

 

[prtuc2]

Crack w/o the speedball upgrade works fine for 1 day, then I upgrade the speedball.  The speedball upgrade works fine initially, but after 3rd days on terminal 14U the soldering iron starts melting and the right channel is completely out and after some recommendations you told me to get replacement parts for the 4 transistors for the larger PCB board for the speedball upgrade.  Now I can't seems to power up the amp.