How to measure a collector voltage

[MaccAu]

Hello,
I am pretty new to measuring voltages. I have a SU-Z35 Technics amplifer with a SVI2004A IC installed, amp works fine with original IC, so it cant be my recap, re wiring work.

How to do i measure voltage of the Collector. I know its the middle pin? on the transistor, E is the emitter and B the Base. I use DC 500V on the multimeter and checked the voltages of the jumper pins.

Is it the same procedure, -ve on the case and +ve on the collector fire up amp, take reading turn off?

Thank you Sam

An externally hosted image should be here but it was not working when we last tested it.

 

[JonSnell Electronic]

The Collector voltage is taken between the Collector and Emitter.
For reference, have a look at this link;
Learn About Electronics - Fault Finding on Transistors

 

[rayma]

Is it the same procedure, -ve on the case and +ve on the collector fire up amp, take reading turn off?

Yes, but the trick is to not short it to anything else. Often, it's best to use a component
that is connected to the collector as a test point instead.

 

[AndrewT]

Yes, but the trick is to not short it to anything else. Often, it's best to use a component
that is connected to the collector as a test point instead.

VERY MUCH so.

Look at the back and find a resistor off that trace and clip on a "clippable" probe so that you don't slip.

I have damaged a few amplifiers by letting a probe slip and short two transistor leads. It does a lot of damage !
One never learns from one's mistakes.
One learns by getting it right, or being shown how to get it right.

 

[rayma]

VERY MUCH so. Look at the back and find a resistor off that trace and clip
on a "clippable" probe so that you don't slip. I have damaged a few amplifiers by letting a probe slip and
short two transistor leads. It does a lot of damage ! One never learns from one's mistakes.
One learns by getting it right, or being shown how to get it right.

Yes, TO-92 packages are almost impossible without special miniature probes.

 

[AndrewT]

Yes, TO-92 packages are almost impossible without special miniature probes.

and To126/220

 

[MaccAu]

The Collector voltage is taken between the Collector and Emitter.
For reference, have a look at this link;
Learn About Electronics - Fault Finding on Transistors

Thank you for the link and reply Jon. I am a bit confused about taking the voltage between collector and Emitter, so i take readings of both.

Yes, but the trick is to not short it to anything else. Often, it's best to use a component
that is connected to the collector as a test point instead.

Thansk Ray, okay, so I was correct with negative probe on case and positive on the collector which I assume is the centre pin as E and B are printed either side of the transistor.

Thanks Andrew, i am very nervous about power. I can wedge bits of rigid plastic so the probe will not touch the metal of E and B, that way it should be safe, I hope

 

[Art M]

1. Power down
2. Connect EZ Hook type test leads
3. Power up and measure
4. Power down

Congratulations... you just saved your self from loads of misery.

 

[AndrewT]

.................. Thansk Ray, okay, so I was correct with negative probe on case and positive on the collector which I assume is the centre pin as E and B are printed either side of the transistor.
................

2sa/c transistors have the Collector in the middle.
All the BC, Eline and 2N have the Base in the middle. Except a few "specials" like BCxxxL

 

[MaccAu]

Thanks Art and Andrew,