D#$$# it may have smoked the Archon head!

[Ascension]

Walked in the music room last night to play a little flip the amp to standby and let it warn then on and --nothing? Start checking everything and the plastic input jack on the Blackstar cab had come apart and dead shorted !! Replaced the jack but now the tubes light but the amp is stone cold dead so bet the dead shorted output fried the $%$# transformer. Locked down with COVID this has been the week from HELL and now this just DAMN!! Pulled out the old Carvin X 50 head as the MT 15 is at my Church and had forgotten just how much of a wicked 80's/90's metal tone machine this old X amp was. It's just classic modded Marshall style metal tonal NIRVANA! Now I have to deal with the carnage with the Archon. oed:!!

 

[Gtrjunior]

Are you 100% sure the tranny is fried?

 

[GuitarStv]

Chinese build quality?

 

[Ascension]

Are you 100% sure the tranny is fried?

Not yet but tubes are lit and nothing. The amp was idling fir a few after I fired it up before I hit it with the guitar volume down and it was just dead. Started checking connections and the jack just fell into the cab when I checked it as the nut had backed off the jack it likely was shorting. Got t all back together and now have nothing. Pulled out the old Carvin and plugged it in to check the cab and it works so--. My thoughts are it run with a dead short on the output for about 10 minuets. Had strung a guitar and plugged it in to stretch the strings and let them set before I locked the nut but got called away before I fired it up. The perfect storm and got some thing for sure.

 

[Ascension]

Chinese build quality?

The MT 15 is the China amp the Archon is US.

 

[Demanic]

10 minutes? That's definitely long enough to do some damage.

Sent from my SM-A115A using Tapatalk

 

[ehdwuld]

run the effects send out to headphones or something

see if you are getting signal from the amp

plug directly into the return and see if anything comes out


in the electrical world its called loop test
divide the circuit in half
check each half
then repeat til you find the bad component

could have a blown speaker

 

[GuitarStv]

The MT 15 is the China amp the Archon is US.

Modern American build quality?

 

[Gtrjunior]

Not yet but tubes are lit and nothing. The amp was idling fir a few after I fired it up before I hit it with the guitar volume down and it was just dead. Started checking connections and the jack just fell into the cab when I checked it as the nut had backed off the jack it likely was shorting. Got t all back together and now have nothing. Pulled out the old Carvin and plugged it in to check the cab and it works so--. My thoughts are it run with a dead short on the output for about 10 minuets. Had strung a guitar and plugged it in to stretch the strings and let them set before I locked the nut but got called away before I fired it up. The perfect storm and got some thing for sure.

Was the cab in standby while idling? I’m assuming it has a standby (my Blackstar HT-20 doesn’t)
I would think in standby there shouldn’t be any way to fry the tranny?
And you checked both fuses? If you have power the mains fuse is still working but possibly the other one blew out?

 

[Lewguitar]

Are there fuses you can check?

 

[Demanic]

The op said his Carvin head worked through the cab.
10 minutes of signal going to short through the tranny.

Sent from my SM-A115A using Tapatalk

 

[Ascension]

Was the cab in standby while idling? I’m assuming it has a standby (my Blackstar HT-20 doesn’t)
I would think in standby there shouldn’t be any way to fry the tranny?
And you checked both fuses? If you have power the mains fuse is still working but possibly the other one blew out?

Amp was running I got a call right as i was firing the amp up to seat a set of strings before locking the nut. came back from the call and rolled the volume up and nothing. Started checking connections and when I checked the input into the cab the jack fell into the cab:eek2:. The nut had backed off the jack and it was likely shorting the input after the plug had backed out. Had no reason to suspect any problem as haven't had that cab out in many months was just a freak thing. Was a plastic jack and nut that came in the cab patched it back together for now and ordered a high end all metal real jack this afternoon off ebay as this will NOT happen again. Cab works fine now but the amp has no output at all. Good idea pulling off the loop to see if the Pre is working. Tubes are lit but nothing no hiss nothing. Will get at it tomorrow and see if I can diagnose it further. Wife has COVID and have been stuck in the house for over a week so this was NOT what I needed to deal with right now.

 

[Gtrjunior]

Stay safe and prayers for your wife

 

[Artie]

Couple of quick notes:

1. The natural state of an input jack is "shorted" when nothing is plugged into it. That's done on purpose so that you don't "float" an amp input when nothing is plugged in. Now, if it fell inside and landed against some high voltage component, that could be different.

2. Having the output tranny shorted, if there's no signal, also won't hurt anything. There would have to have been a signal going through it, while shorted, to damage the transformer.

 

[Ascension]

Couple of quick notes:

1. The natural state of an input jack is "shorted" when nothing is plugged into it. That's done on purpose so that you don't "float" an amp input when nothing is plugged in. Now, if it fell inside and landed against some high voltage component, that could be different.

2. Having the output tranny shorted, if there's no signal, also won't hurt anything. There would have to have been a signal going through it, while shorted, to damage the transformer.

Know that on the input to the amp. This was the input to the cab where the jack failed so likely the amp saw a dead short to the output of the power amp section. Freak thing the plastic nut on the factory jack backed off and the jack fell into the cab when i started checking connections while the nut stayed with the plug from the speaker cable. Afterwards the amp was stone dead in output. Never had a reason to suspect an issue with the cab as this one has not been out of the house or unplugged in over a year it has stayed in my music room. Have a couple of these coming to replace the jack this will NEVER happen again! https://www.ebay.com/itm/Jack-Pure-...a=1&pg=2060778&_trksid=p2060778.c100290.m3507 Now I have to deal with the damage to the Archon though. Still have both the DC 5 and the Carvin heads plus the MT 15 at Church and a couple combos so have other rigs to play but:banghead:!

 

[Artie]

This was the input to the cab where the jack failed so likely the amp saw a dead short to the output of the power amp section.

Ah. Sorry. Didn't catch that part. Ouch!

 

[ErikH]

Hopefully it's just the output tranny. Unless there's some other fail safe circuitry to protect the transformer from damage.
For the cab jack nut, put some clear nail polish over the threads and then tighten it down. It won't come loose again.

 

[Mincer]

This is all terribly frustrating. These are so complex that it is almost impossible to open it up and see something obvious. Hopefully you can update us with good news soon.

 

[Bogner]

I still think there is a fuse hidden away inside the amp that blew that may be harder to find. I am hoping so for you anyway.

 

[Ascension]

For the cab jack nut, put some clear nail polish over the threads and then tighten it down. It won't come loose again.

Couple of drops of super glue on the threads for a temp repair but have one of these incoming won't happen EVER again!
https://www.ebay.com/itm/Jack-Pure-...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649