fullheadofnothing
Moderator
there must be a fault in a wire between one of those terminals and your power transformer. Check continuty/resistance of those wires.
No sound, no tubes lighting up - did resistance checks
- Thread starter drewhaynes
- Start date
drewhaynes
New member
I'm sorry.. I'm a little new to this... where should I be checking specifically?
fullheadofnothing
Moderator
There are twisted wires
They connect the power transformer
Where your voltage is correct
To your tube socket
Where it is not
The problem must be in one of those wires.
Wires have very low resistance. Measure the resistance between the socket and the transformer.
I am now logging off for the night.
They connect the power transformer
Where your voltage is correct
To your tube socket
Where it is not
The problem must be in one of those wires.
Wires have very low resistance. Measure the resistance between the socket and the transformer.
I am now logging off for the night.
drewhaynes
New member
Unless my multimeter is just jacked... since soldering B7 and B8... I'm now seeing zero volts at the plug right where power comes in, as well as on the top two adjacent posts on the transformer where I was initially instructed to test. Not sure what to do from here...
drewhaynes
New member
So... bigger issue maybe? I noted last night that I was no longer getting voltage readings after resoldering B7 and B8... turns out, that wall outlet is no longer working at all - cell phone chargers and things like that are getting no power there. I'm hesitant to try the amp on another outlet now... no breakers in the garage are tripped.
That isn't a problem with the amp, I would plug it into a different outlet. An outlet in the US will deliver 15A at 120V. The Crack fuse will pop when you get over 1A of current draw.
drewhaynes
New member
Sorry, I realize that the outlet is the problem, I just didn't know if I shorted something in the amp that caused it to trip something. I'll test again shortly.
drewhaynes
New member
Caucasian Blackplate said:
Ok, update... I fixed the outlet and I'm now reading 120v at the posts where the 120V plug enters, as well as the posts on the switch, but I am now reading 0V-AC at the two adjacent terminals on the transformer itself, whereas prior to soldering B7 and B8 I was reading 120V at those terminals as well.
Does that give us any useful info?
Again, thank you guys SO MUCH for helping... I'm hoping I can resurrect this thing after years of no use. My only other amp is an O2, and it may be faulty memory, but I still have dreams of the Crack + HD650 destroying what the O2 can do with HD650/HE400/D2000!
Test the voltage between L and N terminals on the IEC power entry module.drewhaynes said:
Test the AC voltage from N to each side of the power switch with the power switch on.
drewhaynes
New member
I just messed around with a few things and I am now back to reading 120V at the top 2 adjacent terminals on the transformer. I tested the wires that run from the top RIGHT 2 adjacent transformer terminals that run from the transformer to the B7 and B8... I measured 0 or near 0 ohms resistance across these wires, and I measured ~6V from the centermost TOP RIGHT 2 terminals on the transformer to B7 and B8. I can take pics of the terminals I'm referring to if that helps.
Do you also get 6V AC at B7 and B8? Is the key molded into the plastic base of your 6080 still attached? (Sometimes they break off)
drewhaynes
New member
Yes I was getting 6VAC at B7 and B8 from the transformer... the key notch is still on my tube and I have tried 2 different 6080 tubes. Still no light in the tubes :/
B7 and B8 are pins 7 and 8 on the octal socket. If you have 6V between those pins and you have a 6080 properly inserted into the socket, it will glow.drewhaynes said:
drewhaynes
New member
Caucasian Blackplate said:
I'm back... long weekend, so hoping to try some more troubleshooting. I was reading 6V from somewhere on the *transformer* to B7 and to B8, but I believe I was showing 0V *between* B7 and B8. I will retest and post pictures of the readings, showing where I am testing.
EDIT: Also, I have not had my manual in a very long time. I can find the list of voltage checks on this forum, but are they *all* performed with one lead on ground, or are many of them measuring between specific combinations of terminals?
To measure B7 and B8, set your meter to AC volts and put one probe on B8 and one on B7.
drewhaynes
New member
Sorry, miscommunicating - I realized how to test between B7 and B8, I just meant for the general list of voltage checks on the crack, wasn't sure if they were testing from ground to each terminal.
Anyhow, I went ahead and retested between B7 and B8, as well as testing from where I *think* the transformer appears to be powering B8 and to B8 itself. I assume there should be a reading from this top terminal on the transformer to B8?
Anyhow, I went ahead and retested between B7 and B8, as well as testing from where I *think* the transformer appears to be powering B8 and to B8 itself. I assume there should be a reading from this top terminal on the transformer to B8?
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drewhaynes
New member
Is the Crack plugged in and powered up for those readings?
drewhaynes
New member
Caucasian Blackplate said:
Yes, I just confirmed by testing from the "power cord receptacle" (not sure the term) to the output of the power switch, getting ~120V. I also just tested from that same top, next to farther right, terminal on the transformer, to B7 and also to B8, checking for *resistance*. I got 0.2ohms from transformer to B8 and 0.5ohms from same transformer terminal to B7. Is that strange that both B7 and B8 would have low resistance to the same transformer terminal?
EDIT: Discovery! I could swear that I had read 6V from the very top RIGHT transfomer terminal to both B7 and to B8 at one point, but I could not replicate it. I was just performing that test again, and when the alligator clip pressed juuuust right on the transformer terminal, the 2 LEDs under the smaller (input?) tube lit up! I think the solder joint on that transformer terminal is crap - I'm going to resolder now. Hypothetically... could my entire issue be that terminal?
That resistance isn't a problem.
Put one probe on terminal 4 of the power transformer and one probe on terminal 5, then check that AC voltage.
Put one probe on terminal 4 of the power transformer and one probe on terminal 5, then check that AC voltage.
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