Voltage Problems after Installing the Speedball

[Yzarc111]

I have just finished installing the Speedball upgrade and have found many of the terminals have the incorrect voltages and 2 of the LEDs are not lit. I also experienced a large spark when I was testing the terminals. Everything was working fine before I added the Speedball.

Terminal Voltages:
1. 75 - 90 (15)
2. 170 (197)
3. 0 (0)
4. 170 (197)
5. 75 - 90 (77)
6. 0 (0)
7. 100 (190)
8. 0 (0)
9. 100 (170)
10. 0 (0)
11. 0 (0)
12. 0 (0)
13. 170 (197)
14. 0 (0)
15. 185 (209)
20. 0 (0)
21. 206 (221)

I attached pictures of the broken LEDs and photos of the main body.

Any help would be appreciated as I am a complete novice with all of this.

 

[Doc B]

Was the spark caused when you were using the meter probe?

 

[Paul Birkeland]

The red wire between A4/5 is basically touching the chassis.  This is the wire that heats your 12AU7, and if you short this connection to the chassis, you'll end up needing a new power transformer.

Often issues like yours will happen when the 2N2907 and 2N2222 transistors are swapped. 

-PB

 

[Yzarc111]

Was the spark caused when you were using the meter probe?

Yes it was.

 

[Yzarc111]

The red wire between A4/5 is basically touching the chassis.  This is the wire that heats your 12AU7, and if you short this connection to the chassis, you'll end up needing a new power transformer.

Often issues like yours will happen when the 2N2907 and 2N2222 transistors are swapped. 

-PB

I just checked if the wire between A4/5 and it doesn't appear to be touching the chassis and I am 100% positive the 2N2907 and 2N2222 transistors are in the correct position.

 

[Paul Birkeland]

You should still clean that up a bit.  I'd also trim the little finger of wire leftover from the LED that's menacingly close to the pin next to it.

For the C4S issue, try reheating the center joint on the MJE-350 feeding the offending terminal.

 

[kgoss]

Also from the picture it looks like you didn't trim the leads of the resistors and transistors on the bottom of the C4S boards very close if at all.  If that is the case there is the danger that a lead got bent when you mounted the boards causing a short.  The best thing to do is use diagonal cutting pliers and trim all the leads close to the board after you solder.

 

[Doc B]

A spark followed by dark LEDS sometimes means that the small transistor was blown. I think there is a procedure listed somewhere on the forum to check the transistors. I have to run to a meeting, but perhaps someone else can help guide you the test procedure.

 

[Yzarc111]

Also from the picture it looks like you didn't trim the leads of the resistors and transistors on the bottom of the C4S boards very close if at all.  If that is the case there is the danger that a lead got bent when you mounted the boards causing a short.  The best thing to do is use diagonal cutting pliers and trim all the leads close to the board after you solder.

I have trimmed all the leads close to the board. Is there a way to check if I have already caused a short?

 

[Yzarc111]

You should still clean that up a bit.  I'd also trim the little finger of wire leftover from the LED that's menacingly close to the pin next to it.

For the C4S issue, try reheating the center joint on the MJE-350 feeding the offending terminal.

I have trimmed the wire leftover and reheated the center joint on the MJE-350 and I am now getting 15V from Terminal 1 as opposed to the 192V I was getting before. I am very confused.

 

[Paul Birkeland]

Are you getting 15V on T1 an the socket LED glowing, or just 15V on T1?