Crack OTL 1.1 + Speedball 1.1 Small board OB Voltage 153V

[stevenbravo1410]

Hey guys! Im building the Speedball update, i already assembled the Crack and it worked perfectly, so after enjoying it a few hours i decided to install the Speedball upgrade

Everything regarding voltage and checks work perfectly until i check the OB in the small board which reads double what it should at 150V

I followed the diagram and check the R1 resistances in the small board and both mark 238 Ohms, so i checked if the orientation was right and yeah it was, and yes the lower tube fully lights each section

One thing i noted tho is that one of the LEDs in the 9pin socket stopped turning on, the one connected to A8 is working fine, but the other one doesnt turns on

Here i send some pictures to have as reference.

I already tried soledring the MJ correctly, reflowed it 3 times as well as the whole board and it just simply lowered the OB voltage by 12v give or take, another note, im using some black and white cables from the crack kit to connect the pcb because the wire that came with the speedball broke several times while handling and moving the pcb board, i have the correct wire cutter, did it manually to try as well, so i got tired of those cables breaking and i used some of the crack, but the problem already existed with the previous cables and the new ones helped lower the voltage a little bit.

One thing i do notice when i turn on the kit is that the left LEDs of the pcb board turn on first, and then after a delay of around 2 or 3 seconds the LED/ of the right then turn on, i dont know if the info helps but its what i observed

Thanks in advance for the help!

 

[Paul Birkeland]

What is the voltage at A3?

Try holding your soldering iron onto the center leg of the MJE350 on the offending side, then count to 10, then pull it off. That should assure that it's adequately soldered.

-PB

 

[Jameson]

Kudos to you for following the troubleshooting diagram, by the way.

 

[stevenbravo1410]

What is the voltage at A3?

Try holding your soldering iron onto the center leg of the MJE350 on the offending side, then count to 10, then pull it off. That should assure that it's adequately soldered.

-PB

The voltage at A3 is 13,06V

Tried the 10 seconds stuff and measured resistances and voltage, it was still 238Ohms and 160,6V for the OB, tried again and still the same. If I try to move it it feels really sturdy and attached to the PCB.

OA reads 74,1V which passes the check
IA reads 170,9V which passes the check
B-A/B reads 000,7V which passes the check
and OB reads 160,6V which is 70V extra from where it should be.

The A3 mini led didnt turned on after i tried this either, here i post some pictures of both tubes turning on properly on both sections, did in the dark so you could see more clearly the filaments heated.

Any other suggestion?

 

[stevenbravo1410]

Kudos to you for following the troubleshooting diagram, by the way.

It was really helpful to check other stuff that might be causing troubles and it did help me understamd my product a lotnmore deeply.

Manuals are 10/10, chefs kiss. Kudos to the team for making those as clearly as they are

 

[Paul Birkeland]

If you fit a wire jumper between A3 and A8, I'd imagine your voltages will land where they are supposed to be, or replace the LED at A3.

 

[stevenbravo1410]

If you fit a wire jumper between A3 and A8, I'd imagine your voltages will land where they are supposed to be, or replace the LED at A3.

Yup! This was it! Now OB its at 68/70V Thanks a lot for your help Paul!

Ive been testing it for 45 minutes at least, everything in order except that sometimes when i just plug the headphones it sounds like a needle scratching on a vinyl record for maybe less than 30 seconds in the aggregate, its intermittent, then after that it just stops happening completely and all sounds normal.

pd: this sounds awesome with my senheiser hd 600, i cant explain it with words, and i only installed the small board