Hi Fabio,
Sorry, I replied to your post but see i must have clicked the wrong tab and it didnt make into the thread.
I will have time to check some voltages tomorrow [after the Mexico World cup game...I'd be a disowned gringo if I didn't watch it. Even the local church will be closed!]
You wrote:
So, it seems this power supply is a good starting point to start checking.
A lot on the 465 relies on the +15V rail and there are a lot of small tantalum decoupling capacitors spread everywhere in this rail.
They are prone to get shorted, sometimes poorly shorted, when they will heat and become visibly burnt, but sometimes they will go dead shorted and then they don't heat and will trigger the current overload protection of the power supply.
A good way to tell is by measuring the voltage drop across the current sense resistor that makes the over current transistor to conduct and drop the output voltage.
It's usually a resistor of less than 1 Ohm (I don't have the manual of the 465 at hand right now) and it mustn't be dropping more than 0.5V.
Would you please explain a bit further? I do see a number of the tantalum caps. Are the 1 ohm resistors you mention associated with each one of them? Do you think i can test the Ta caps in circuit with an ESR meter?
Thanks, Russ
