My trusty Orange AD15 isn't making noise anymore....

[Sooner]

I would test the following:

TP1 to TP2 (or TX6 to TX8 since you can't get to TP2): Should be 6.3V AC
TP3 to TP4: Should be 5V AC
TP5 to TP0: Should be 332V DC
TP6 to TP0: Should be 326V DC
TP7 to TP0: Should be 259V DC
TP8 to TP0: Should be 222V DC

From what you've posted it sounds like your transformer is okay and there's probably a bad connection somewhere that's keeping the 6.3V getting to the pilot light and heaters to the pre and power valves.

[FleshOnGear]

LPL, I think Sooner is right. It looks like you are testing TP1-4 relative to ground, which is why you are getting those readings. TP1-2 should be tested relative to each other to get 6.3V and TP3-4 should be tested relative to each other to get 5V. When you measure in VDC the heaters of a tube rectifier relative to ground, you will read the full B+.

Like stated before, the GZ34 heater winding is separate from the heater winding for the rest of the tubes, so the GZ34 lights up. It seems clear that the others aren't getting the 6.3V they need. Your 3.3V reading seems correct, if you reference TP1 to ground, so that's a good sign. As Sooner suggested, did you test the TX6 and TX8 connections yet?

This seems like the same issue with the amp at my shop, based on what the customer described. I'll let you know what I discover.

[jontheid]

At this point I wouldn't bother trying to find exactly where the heater supply fails.
I'd just bite the bullet and hard-wire all the heaters.
I really shouldn't be that difficult a job.
Even if you find one dodgy connector now, it is possible another will fail in the future, like Sooner's amp.
Hard wire those suckers and I bet your amp is fixed, and is reliable.
Your tests so far indicate that the rectifier heater is working and you are getting good HT voltage.
The only thing that can be stopping the amp from working properly is the heaters.
Cheers
Jon

[Sooner]

Even if you find one dodgy connector now, it is possible another will fail in the future, like Sooner's amp.

Actually it's been just one problem connector on my amp, but yes, the best solution would be to hard wire all of them.

[Les Paul Lover]

I would test the following:

TP1 to TP2 (or TX6 to TX8 since you can't get to TP2): Should be 6.3V AC
TP3 to TP4: Should be 5V AC
TP5 to TP0: Should be 332V DC
TP6 to TP0: Should be 326V DC
TP7 to TP0: Should be 259V DC
TP8 to TP0: Should be 222V DC

From what you've posted it sounds like your transformer is okay and there's probably a bad connection somewhere that's keeping the 6.3V getting to the pilot light and heaters to the pre and power valves.

LPL, I think Sooner is right. It looks like you are testing TP1-4 relative to ground, which is why you are getting those readings. TP1-2 should be tested relative to each other to get 6.3V and TP3-4 should be tested relative to each other to get 5V. When you measure in VDC the heaters of a tube rectifier relative to ground, you will read the full B+.

Like stated before, the GZ34 heater winding is separate from the heater winding for the rest of the tubes, so the GZ34 lights up. It seems clear that the others aren't getting the 6.3V they need. Your 3.3V reading seems correct, if you reference TP1 to ground, so that's a good sign. As Sooner suggested, did you test the TX6 and TX8 connections yet?

This seems like the same issue with the amp at my shop, based on what the customer described. I'll let you know what I discover.

At this point I wouldn't bother trying to find exactly where the heater supply fails.
I'd just bite the bullet and hard-wire all the heaters.
I really shouldn't be that difficult a job.
Even if you find one dodgy connector now, it is possible another will fail in the future, like Sooner's amp.
Hard wire those suckers and I bet your amp is fixed, and is reliable.
Your tests so far indicate that the rectifier heater is working and you are getting good HT voltage.
The only thing that can be stopping the amp from working properly is the heaters.
Cheers
Jon

Thank you all for your input.
Hardwiring them all isn't gonna be a very hard job, so if you all think that's the sole issue, I'll just go and do it.

At least then we'll know if that's that, and it'll be nice to eliminate that as an issue for sure.

Only downside is that it might take me a while to find the time to do it.
Especially now the dishwasher has packed in...... My wife seems to think it should take priority in the to fix list......

Anybody is any good at diagnosing dishwasher problems??? may be I'll just start a new thread for that......

[Randy Bass]

One time my dishwasher was broke, so I gave her $50. Hope that helps.

You should just bite the bullet and buy a new Midland Kitchen and be done with it.

[a.hun]

My wife has been known to rate the dishwasher as her 'best friend'. I know she loves me too, but you can't ignore that sort of sentiment...


Andy.

[bclaire]

We don't have a dishwasher... I generally do them as I go along.

I'd try replacing the fuse - if it only looks good, it could be bad still. I've had that happen before where a visually good fuse had actually blown....

[Jondog]

Does the AD15 has a fuse for the heater wires? The Rocker does and I had to replace it once as the amp was doing the same.

[steamboat]

Yea there's a fuse for the heaters...I'd test it not just look at it like billy said.

Edit. There's no fuse for the heaters! My bad

[Les Paul Lover]

Yea there's a fuse for the heater...I'd test it not just look at it like billy said.

How would you test it? I tested it for resistance and got a low Ohm figure - can't remember exactly what. Not 1 anyway!!!!!!

[steamboat]

Yea ohming it out would work. You should see like .1-.3 of an ohm. Something really low. Wires are usually like .2-.6 ohms there shouldn't be much resistance. But there should be something. Maybe just replace it to rule it out if you have some spares handy. Its a good idea to always have back ups. Especially when going out live.

[Sooner]

A fuse is not the problem. There are two fuses in the AD15. The mains fuse and the HT fuse. If the mains fuse was bad nothing would light up. If the HT fuse was bad all of the valve heaters and the indicator light would still light up. There is no fuse specifically for the heaters.

[jontheid]

Your test results (measured to ground) show that the mains transformer secondary that does the heaters is working:

TX6 3.15V DC 3.3V AC
TX7 0V 0V
TX8 3.15V DC 3.3V AC

So even if there was a fuse (which there isn't) it couldn't have blown.

Also the schematic gives TX6 and TX8 as 3.15VAC (not dc). The TP and TX voltages that have letters after them are all AC voltages. The ones without letters (such as TP5,6,7) are DC voltages.

These measurements were made relative to ground. Heater voltage is between TX6 and TX8 and is 6.6V ac, TX7 is presumably a centre tap for the heater winding, and is grounded. This is all good. Your heater voltage is slightly high, but this is likely because, due to the fault in the heater wiring, no current is actually flowing in the heaters. If it were I bet this voltage would come down a bit.

Cheers,
Jon

[a.hun]

So looks like dishwasher first, then hardwire those heaters...


Andy.