Egnater

[Valvehead]

need a scem for a Egnater Tourmaster 4212 head.

I have a BIG short even in standby--i suspect the power supply , but the pcb is highly populated

[lowell]

You remove the power tubes and try again?

[Valvehead]

yes. it does this with no tubes and the heaters and B+ leads disconnected from the tube pcb .

i have a light bulb limiter i use and the amp lights up a 75w bulb SUPER bright

I pulled the power supply pcb and so far I can find any bad parts --- however, i have no way of testing the caps

[lowell]

That being the case you might try seeing if the PT is bad. If you get a decent resistance when measuring the filter caps then I'd look elsewhere. They COULD be a problem, and leaky, but if you have a dead short and the bulb is bright then they'd most likely show as shorted with the meter. I would try disconnecting PT secondaries if it were me and I couldn't find a schematic.

[Valvehead]

i just got a scem from egnater.

i did stick a meter on the filter caps--most read around 12 Meg ohms , a couple read open

i will be working on it tonight .

[Valvehead]

well.... i have the entire power supply removed.... and i still have a major short .. The only thing it might be is the PT itself , OR there are 3 caps in there and all are on the ac lines coming in--maybe shorted?

problem is i cant see the caps anywhere in the amp ! and They arent on the pcb i removed..

I emailed Egnater--i will see what they say

[Valvehead]

have a look

[soundguruman]

Interesting. I never seen one fail.
(Bruce, you are still my hero)

[oleg solo]

Can be there is a full scheme Tourmaster? Send me please: os-ds@yandex.ru Thanks!

[Valvehead]

Anyone ever work on these ? I looked for a long time for those 3 caps to no avail--i emailed egnater but no response yet .

[nickb]

Valvehead - have you done what lowell said " disconnect the PT secondaries" - you can lift all the diodes one at a time to do this to narrow the problem area down.

[Valvehead]

there is nothing hooked up to the secondaries at all right now

[Jazz P Bass]

If the secondaries are floating & the fuse still blows, that pretty well confines the issue to the power transformer.
It's bad.

[g1]

If I understand correctly, the PT secondaries are disconnected but the bulb still glows bright. There are three caps shown on the PT primary which you cannot find but wish to rule out.
I would expect those caps to be wired to the IEC receptacle (power socket), or perhaps inside of it (if it is a sealed box type power socket). They are before the power switch so I think you can pretty much rule them out.
I would imagine the PT is getting hot even with the secondaries disconnected?

Edit: Or, what he said (sorry JPB, didn't see your post in time).

[Valvehead]

G-one , i never thought of that ... caps inside the IEC . I can disconnect the power switch from the ac recepticle---if there are shorted caps inside it should pop the breaker on my outlet strip (without my current limiter) .... yes?

I will see if the pt gets hot -- i never checked that .