new liver pool build not passing the light bulb limiter test

[harris51]

I followed the Ceriatone layout for the liver pool to a tee. for the life of me does anybody make house calls in Sacramento, Ca ? No seriously anybody.

[passfan]

Got a digital camera ? Start posting gut shots and you'll probably be playing it by nightfall.

[Randy Magee]

You have a mistake somewhere else it would be rocking... I had a couple of dumb mistakes in my Express build and I would have sworn that I was as careful as I could have been... you are in good company here, your amp will get diagnosed and fixed soon!

[martin manning]

Isolate the problem: Remove all the tubes and put the standby switch in standby. Now what happens to the light bulb when you turn the AC power switch on?

- If it still stays brightly lit you have a problem in the filament circuit or in the power supply before the standby.

- If you have to take it out of standby for the light to stay lit the problem is in the power supply or plate circuits after the standby switch.

Do post pictures so we don't make erroneous assumptions, such as in the above I'm assuming that you have something pretty close to the schematic, your standby switch is wired correctly, and that you know for sure which way is in standby.

[harris51]

when I use the bulb test there's no tubes when standyby is off and then I turn power switch on light bulb lights up pretty bright, here one of many pic Ill be sending believe me I really appreiciate any help, Thanks Mike

[harris51]

let me know if I should send any different pics Thanks

[martin manning]

The lightbulb is in series with the AC power, correct? What wattage is the bulb you are using?

Now, with the standby off, you turn on the AC power on and the bulb lights up brightly and stays that way?

Do you have a multimeter to measure voltages and resistances?

[martin manning]

Oops.

[harris51]

Im using a 40 watt bulb and I think the bulb limiter is in series I hope it is. I have a multi meter to measure I just don't know the protocal in doing it, can you talk me through it? yes when the standy by is off and the ac switch is on the bulb stays on bright

[Colossal]

Is this turret soldered?

[harris51]

yes from underneath
I'll throw some on top too.

[martin manning]

Ok I see from the Ceriatone layout that the standby is right after the rectifiers, and there is a bleeder resistor (the 220k to ground at the power inlet) after the standby, which will bleed-off the charge in the filters (after a few minutes).

Since the bulb glows with the standby off (i.e. in standby mode) there is something wrong in the primary, the filament circuit or the in the secondary up to the rectifiers.

Measure resiatance from the hot and neutral of the line input to ground. Both should be infinite resistance.

Measure the resistance from the hot side of the standby switch (yellow wire) to ground with the red probe on the switch. You should get infinite resistance. While you're there, measuring from the other side of the standby switch to ground you should see a couple hundred thousand ohms (the bleeder resistor, mainly).

If the above checks out, then suspect the filament circuit has a short to ground or across the winding. To check that disconnect the filament center tap and measure from any point on the filament wiring to ground. If you get infinite resistance (good), then disconnect one of the other heater wires from the transformer measure across any pair of filament pins (tubes out), say 4 and 5 on an EL84 socket.

[harris51]

could it possibly be that my fuse is wired in reverse

[harris51]

dumb question do I do the reading with the amp plugged in or off switch up or down

[harris51]

should pt grounds have there own ground point?