Ceriatone HRM MKII build, no sound.

[Homebelly]

Hi.

I'm kinda taking a punt here..
I have also posted this on the ceriatone forum in an attempt to spread my net wide.

Any ways..
I just clipped one of my KT77's and broke the damned thing, so now i'm hanging out while i wait for a replacement.

Mean time, while i wait, i'm hoping someone might be able to give me a pointer.

Before the tube broke i had biased the amp up and was ready to plug in my guitar.
I plugged in and turned up the volume and, nothing.
No sound.

All of the tubes were lit up and getting power.

I checked my guitar cable and changed to four others, same result.
I swapped guitar, same result.
I even swapped speaker cable and cab.. same result.

I've drained the caps and taken out the preamp board and the power amp board and checked the wiring and it all looks good.

I've checked the wiring against the layout diagram and it looks good, but i'll check again when i have a clearer head. I'm a little pissed at my self for
being dumb and breaking the KT77.

I've traced the wiring from the boards to the chassis mounted components and it all looks good.

I realize this is a bit abstract, but where would you be looking?

There has been no pops or bangs.
No burning smell.
The tubes biased up fine and the amp seemed happy sitting with current running through it.
Every thing seems all good, except no sound.

Any tips?

Cheers.

[DonMoose]

Never mind - delete

[Structo]

Need more details and some close up pictures in order to help.

[erwin_ve]

Did you try inserting signal in the Fx loop? Or from the fx loop to a other amp?

[Homebelly]

I'm gonna sit down with my DMM set for continuity testing today.
I'm guessing there is a problem with either the input or the output jacks.
My reasoning being that all of the tubes are lighting up and none of them are red plating or behaving badly in any other way. There are no loud hums coming out of the actual amps guts and no pops or buzzes when i start prodding parts or connections with a wooden chop stick.
I've visually checked and traced both the preamp board and the power amp board and all connections are good, so if there is a problem there then its going to be a dead component.
I think this is probably just a very simple and silly error with the input or the out put.

[Homebelly]

Speaker jacks are wired mirror back wards.
The bridging wires that should be on the front pins are on the back pins and visa-versa.

Out of interest, can some one explain how i would do a continuity test on the whole amp.
I guessed it was a case of setting my DMM up in continuity mode, then touching one end of a series of parallel components with one probe and the other end with the other probe then hope for a loud beep. But that doesn't work.

Learning as i go,,, learning as i go...

Cheers for the help so far.
Both directly here, and indirectly through the search function.

[butwhatif]

If you don't have a scope, u can check any points with a good meter, once u have verified the DC is right everywhere, put it in AC volts mode, it will show a signal just about anywhere in the circuit when u r playing---

[Structo]

When powering up a new amp you should use a variac or a current limiter to helps show any faults or excessive current draw, such as a short circuit or wiring mistake.

That way you can usually power down before any damage is done.

If you don't own a variac then a simple light bulb current limiter can be built for a few bucks and it can save $$$ if there is a mistake.

You could have easily blown an output transformer with the amp wired the way it was.

[Homebelly]

It lives!!

Speaker outs where the problem.
Stoopid me.

Thanks for all your help.

Cheers.