A request from a non member

[Old Sparky]

As far as I can see, Richaed, you've carried out the transistor checks correctly. Did you get a low(ish) reading from both the Base and Emitter of the 2N3055 to it's collector. Being an NPN transistor, if checked with an analogue meter on an ohms range, a low reading should be obtained with the black lead on the Base and the read lead, first on the emitter (RH pin as looked at from the underside of the device) and then on the collector (The transistor's case). Reversing the meter leads should give a very high or open circuit reading. There should also be a very high or open circuit reading beteween the collector & emitter, both ways round (with the transistor out of circuit). A leaky 2N3055 would almost certainly cause the resistor to get hot, due to excessive current being drawn.
As to the 3300uf Capacitor, when you say you checked it, and found it to be leaky with the mains on, did you mean that the voltage was dropping as you measured it? This might be due to a leaky capacitor, or to a fault in associated components, such as the 3055, if it was still connected.

[richard296]

The 35v 3000 ohm cap actually leaked fluid when i ran voltage tests both sides of it to earth. This was with mains power on. Unplugged later the transistor gave no reading in one direction from both terminals to collector and high reading other direction. The other transistor gave the correct reading to all terminals both directions thank you richie

[Refugee]

The resistor will have to drop something like 24 volts as the rectifier output will be something like 55 volts.
We know that the resistor is rated at either 7 or 10 whats.
We are not far from a value.
The 35 volt capacitor will blow if the power supply is plugged in off load as the voltage rating is not high enough.

[pwdrive]

"The 35v 3000 ohm cap"

Do you mean micro farad or is that a measured leakage resistance?

If it's micro farad then the usual expression is "mfd" or "uf"

Lawrence.

[richard296]

hopefully i will get the new parts this week. I will fit them plug it in do the checks right this time and takei t from there. thank you richie

[richard296]

The damaged cap is 35v @ 3000 uf its on the 40v power supply one of the two orange caps running parallel with each other. thank you richie.

[Refugee]

I would guess that the resistor was either 82 ohms or 100 ohms.
The currant would be either 250 or 300ma.

[richard296]

just an update. I now have the caps and transistors. I saw an article on this forum regards cap esr so i ordered one from china. i wan't to check everything before installing. The old caps were facon 3000 uf VL 35 V! 42 made in italy model 06T.6.30 the new one's are less than half the physical size. 3300 uf and 35v are these ok. the next size up is 4700 uf and 50v. what does the VL 35 and V! mean on the old caps. any help is appreciated thank you richie

[pwdrive]

35 v on the old cap(s) could well be the working voltage rating, generally not to be exceeded.
Bring up the Galanti on the variac whilst monitoring the voltage across the new cap(s) their working voltage must not be exceeded, preferably a minimum of 5 volts below the rated voltage.

Lawrence.

[Refugee]

With the smaller size I would be tempted to go for 63 volt ones as the voltage can climb if it is powered up off load.
This could be what caused the original fault.