Crack not glowing on startup - shorted diodes? [solved]

[Todd]

[SOLVED]

Holy smokes, guys! It works, and it's glorious!

Thanks so much for all of your replies. All of them were very helpful in helping me get it straightened out.

The only thing left for me to do is to pick a stain and assemble the housing.

I'll also be selling off my Fiio e09K + e17 combo and will likely be upgrading to a Schiit Bifrost Uber for a DAC.

I was able to test the Crack using Sennheiser HD600s by connecting the Crack to the Fiio e09K + e17 combo, and from that to my PC.

I'll update the original post with my solution for any other novices stumbling across this thread looking for help, but in short, taking note of these amateur mistakes may do the trick:

Reflow and add more solder to any of your potentially suspect looking joints. Flip the board to see if the joints look good from the other side.
Use alligator clips so that your multimeter probes don't move--I got sparks without one.
If you see an mV on your multimeter when testing voltages, it means milivolts, 1000 mV = 1V, so your larger looking numbers may be perfectly fine.

--

[Original Post]

Hi guys,

Just completed building the Crack today but do not have glowing tube filaments during the power on test. My fuse isn't blown, I've double checked all of the wiring to be in the right places and inspected each solder joint. I did a search on the forum and learned that it might be shorted diodes.

I've attached pictures of my build, including diode tests. I'm under the impression that these values should be between 500-900, but I get a decimal value ~.460. Does this mean I need to buy 4 new diodes from a local electronics parts shop and replace them all? If yes, what would need to change to ensure that it doesn't happen again?

Additionally, my black RCA jack only tests for 86 ohms rather than the suggested 90-100. I reheated the black jack to get it to flow and added some more solder, and resoldered the other end of the white wire connected to the volume knob, but this didn't seem to change anything.

And lastly, my terminal 13 was counting down slowly starting from a low number rather than the suggested slow climb up to 270K. I tried turning on the Crack again after resoldering a few joints to see if the things I did fixed anything, but now terminal 13 tests for "OL." Not quite sure what this means.

imgur.com/a/qNuLf

Any ideas?

-- Edit --

My resistance / voltages, pasted from later comments for reference,

Resistance
Terminal / Suggested / Actual:

1 / * / Counts down from 3-10. Once, it was counting up to 200K, before refreshing and counting down from a low number. The K turned to an M.
2 / * / Also counts down from around 2-3. I can't seem to replicate the counting up consistently.
3 / 0 ohms / 0
4 / * / Counts down from 2-5. Got this one to count up to 200K once as well.
5 / * / Counts down from 2-5.
6 / 2.4K ohms / 2.49K
7 / 2.9K ohms / 2.93K
8 / 0 ohms / 0
9 / 2.9K ohms / 2.93K
10 / 2.4K ohms / 2.49K
12 / 0 ohms / 0
13 / * will climb slowly toward 270K ohms / As mentioned before, seems a bit jumpy and inconsistent. Sometimes climbs up to 200K before refreshing from K to M, and begins counting down. Other (most) times it won't count up, and will start by counting down, similar to terminal 1, 2, 4, it seems. I feel like if I repeated test enough times, I may get the counting up on other terminals as well.
14 / 0 ohms / 0
20 / 0 ohms / 0
22 / 0 ohms / 0
B3 / 2.9K ohms / 2.93K
B6 / 2.9K ohms / 2.93K

RCA jacks:
Ground lug / 0 ohms / 0
Center pin / 90K ohms—100K ohms  / Left (Red) 92.4, Right (Black) 86.4

--

Voltages (no tubes in)
Terminal / Suggested / Actual:
1 / 75-90 / 237
2 / 170 / 237
3 / 0 / 0
4 / 170 / 237
5 / 75-90 / 237
6 / 0 / 0
7 / 100 / 0
8 / 0 / 0
9 / 100 / 0
10 / 0 / 0
11 / 0 / 0
12 / 0 / 0
13 / 170 / 237
14 / 0 / 0
15 / 185 / 238
20 / 0 / 0
21 / 206 / 238

A1 / 90 / 237
A2 / 0 / 0
A4 / 0 / 0
A5 / 0 / 0
A6 / 90 / 237
A7 / 0 / 0
A9 / 0 / 0

B1 / 90 / 238
B2 / 170 / 239
B3 / 100 / 0
B4 / 90 / 238
B5 / 170 / 239
B6 / 100 / 0
B7 / 0 / 0
B8 / 0 / 0

I'm using this multimeter, and have it set to the ohms setting (3 clicks turning the knob to the right).
amazon.com/INNOVA-3320-Auto-Ranging-Digital-Multimeter/dp/B000EVYGZA

[Grainger49]

The first question is always, "How did the resistance and voltage checks go?  Anything out greater than 15%?"

[Todd]

Thanks for the response, Grainger.

The only thing that I was unsure of was terminal 13 which was supposed to climb up to 270k. Instead, mine seemed to be counting down.

The other thing was the black RCA jack at 85 ohms, rather than the suggested 90-100, but that is within 15%.

I inspected all of the wiring and it looked correct. I didn’t get any zero values where I shouldn’t, and no values greater than zero where I should have had zero. I couldn’t see anything to fix--so I proceeded. Doh!

[adydula]

I looked at your pictures...you say the tubes are not glowing? If that's correct then for some reason there is no heater voltage getting to the tube heaters.

Looking at the schematics the heaters have nothing to do with the diodes, its just AC from the secondary side of the transformer windings. The red and black wires from the 6.3 V terminals of the transformer to the power tube then on to the smaller signal tube. I looked at your wiring to the heaters and it looks ok as far as I can tell.

So if the heaters are wired correct but not glowing then the voltage to them isn't getting there or isn't coming from the transformer IMO.

If the 110VAC on the primary side of the transformer isn't wired correctly then there might not be any voltage on the secondary side.

With the tubes out I would check that your getting 110vac thru the switch and to the transformer primary input terminals. Your solder joint from the switch IEC socket to the transformer looks a little "scketchy"...u might reflow that one...

Also measure the 6.3 VAC on the transformer secondary side terminals and see if you indeed have heater voltage there.

All the best
Alex

[Todd]

I looked at your pictures...you say the tubes are not glowing? If that's correct then for some reason there is no heater voltage getting to the tube heaters.

Looking at the schematics the heaters have nothing to do with the diodes, its just AC from the secondary side of the transformer windings. The red and black wires from the 6.3 V terminals of the transformer to the power tube then on to the smaller signal tube. I looked at your wiring to the heaters and it looks ok as far as I can tell.

So if the heaters are wired correct but not glowing then the voltage to them isn't getting there or isn't coming from the transformer IMO.

If the 110VAC on the primary side of the transformer isn't wired correctly then there might not be any voltage on the secondary side.

With the tubes out I would check that your getting 110vac thru the switch and to the transformer primary input terminals. Your solder joint from the switch IEC socket to the transformer looks a little "scketchy"...u might reflow that one...

Also measure the 6.3 VAC on the transformer secondary side terminals and see if you indeed have heater voltage there.

Thanks, Alex. I wasn't super sure which joint looked the sketchiest, so I reflowed all of the ones that I thought might fit the bill. I've attached pictures of my reflowed joints. First time solderer, so sketchiness was expected. I've also added more solder to a few joints that seemed a bit bare (terminals 12U, 13U, and #4 on the transformer).

I'm also not sure how to test for "110vac thru the switch and to the transformer primary input terminals," nor "6.3 VAC on the transformers secondary side" to see if I have heater voltage. But I rechecked all of my resistances/voltages, and with the black/negative multimeter lead on terminal 12 (the ground), and the red on corresponding joints, here are the values I got (picture attached). Does this fulfill what you suggested, or do I need to do something else?

All of my resistance/volt checks seem to be where they should be. The notable things are that the black RCA jack is still at 86 (rather than 90-100, within 15%), and terminal 13 is giving me numbers again. I can't get it to climb up to 270K, though. It seems pretty inconsistent and jumpy. Sometimes it counts down slowly from 5-6. Sometimes it climbs up toward 270K, but stops around 190-200K and refreshes, counting down again from a low number. I'm not sure what this suggests.

What's next? Should I try turning it on again after having done these things, or do I need to get terminal 13 cooperating as expected?

imgur.com/a/YWKsD

PS, the yellow/brown flux that excretes from joints while soldering isn't a bad thing, right?

[Paul Birkeland]

All of my resistance/volt checks seem to be where they should be.

If your tubes aren't glowing, your voltage checks will be way, way off.

I would suggest posting your voltages.

-PB

[Todd]

If your tubes aren't glowing, your voltage checks will be way, way off.

I would suggest posting your voltages.

-PB

Sure thing!

Terminal / Suggested / Actual:

1 / * / Counts down from 3-10. Once, it was counting up to 200K, before refreshing and counting down from a low number. The K turned to an M.
2 / * / Also counts down from around 2-3. I can't seem to replicate the counting up consistently.
3 / 0 ohms / 0
4 / * / Counts down from 2-5. Got this one to count up to 200K once as well.
5 / * / Counts down from 2-5.
6 / 2.4K ohms / 2.49K
7 / 2.9K ohms / 2.93K
8 / 0 ohms / 0
9 / 2.9K ohms / 2.93K
10 / 2.4K ohms / 2.49K
12 / 0 ohms / 0
13 / * will climb slowly toward 270K ohms / As mentioned before, seems a bit jumpy and inconsistent. Sometimes climbs up to 200K before refreshing from K to M, and begins counting down. Other (most) times it won't count up, and will start by counting down, similar to terminal 1, 2, 4, it seems. I feel like if I repeated test enough times, I may get the counting up on other terminals as well.
14 / 0 ohms / 0
20 / 0 ohms / 0
22 / 0 ohms / 0
B3 / 2.9K ohms / 2.93K
B6 / 2.9K ohms / 2.93K

RCA jacks:
Ground lug / 0 ohms / 0
Center pin / 90K ohms—100K ohms  / Left (Red) 92.4, Right (Black) 86.4

I'm using this multimeter, and have it set to the ohms setting (3 clicks turning the knob to the right).
amazon.com/INNOVA-3320-Auto-Ranging-Digital-Multimeter/dp/B000EVYGZA

[Doc B.]

Those would be resistance readings. The next thing to do is measure voltages.

[Todd]

Ah, dang. Thanks for pointing that out. Came into this knowing hardly anything about any of this, so I’ll have to find that setting on my multimeter when I get home and will update with voltages.

[adydula]

Todd, do you a friend that knows more about electricity and how to take voltage readings?

You want to be very careful taking voltage readings so you won't get shocked or short something out.

Its really easy to do if your not careful, hence all the warnings Doc has in the Crack manual.

If you were close to me I would. Be glad to help, I am in North Carolina.

Remember the volts checks are "volts DC" not AC, so make sure you set your meter to read volts DC.

The voltages I was referring to are volts AC.

Alex

[Todd]

All right, guys. Not so great looking as user Caucasian Backplate anticipated--no glowing tubes = far off voltages.

I put on some rubber boots, put the fuse in, plugged in the power cable, switched the Crack on, used helping hands to hold the negative lead from the multimeter to terminal 12 (ground), plugged it in, put my hand in my pocket, and with NO tubes in as suggested by Alex / adydula, here are my voltages (10MegOhm input DCV on my multimeter):

Voltages (no tubes in)
Terminal / Suggested / Actual:
1 / 75-90 / 237
2 / 170 / 237
3 / 0 / 0
4 / 170 / 237
5 / 75-90 / 237
6 / 0 / 0
7 / 100 / 0
8 / 0 / 0
9 / 100 / 0
10 / 0 / 0
11 / 0 / 0
12 / 0 / 0
13 / 170 / 237
14 / 0 / 0
15 / 185 / 238
20 / 0 / 0
21 / 206 / 238

A1 / 90 / 237
A2 / 0 / 0
A4 / 0 / 0
A5 / 0 / 0
A6 / 90 / 237
A7 / 0 / 0
A9 / 0 / 0

B1 / 90 / 238
B2 / 170 / 239
B3 / 100 / 0
B4 / 90 / 238
B5 / 170 / 239
B6 / 100 / 0
B7 / 0 / 0
B8 / 0 / 0

These are pretty off. What does this tell us? Do I need to retest with the tubes in? Using the ACV setting?

Also, thanks for the kind offer to help me out in-person, Alex--I'm in Utah, though!

[fullheadofnothing]

You need to do the tests with the tubes in. I don't see anyone suggesting otherwise in this thread, and it is very clear in the instructions for the voltage tests that the tubes must be in the sockets.

[Todd]

Thanks for the clarification. I had the feeling I should have done it with tubes, but I wasn't sure because user adydula suggested I "With the tubes out I would check that your getting 110vac thru the switch and to the transformer primary input terminals," so I figured doing it without tubes was something to do, and that I'd do it wrong first until someone corrected me rather than risk messing something up if I did it with tubes in. I'll redo it with the tubes in right now and will report back soon.

[Todd]

Aw man. Okay.

Followed the same steps, but this time putting the tubes in. They glowed this time! Woo! Must have been some reflowing/resoldering that did the trick.

Voltages were looking perfect until terminal 6. It was always changing and I couldn't get it to stay on one number, so I reseated how the negative lead was touching terminal 12 since it had moved very slightly. I tested terminal 3 again to see if it would read zero again to verify that everything was looking good, and POP, a blast of sparks.

I've since turned it off and there's some black markings on one of the 3K ohm resistors (white rectangle) as shown in the picture. The fuse is still in tact, though. Everything looks fine except for the explosion marking bit. My resistances are the same as they were before I tested voltages with the tubes in. What went wrong here, and what now? Could it have anything to do with the 3K ohm resistor's proximity to the 22.1K ohm 1W resistor (brown oval with red stripes)?

imgur.com/a/neiVI

[kgoss]

Todd,

You really need to get some meter leads with alligator clips instead of probes. Use the black one to connect to the ground point. Then use the red lead with the probe to measure voltages. That way you only focus on the terminal you are measuring without worrying about the negative lead moving. It makes accidental shorts and getting shocked much less likely.

Follow Paul's directions and he will help you get it sorted out.