component testing with keysight dsox1102g scope

Which kit do you have, can you post a schematic ?

MK

Hi john,

You may find that trouble shooting this short will be easier with a simple analog ohmmeter or multimeter than with a scope. It is a matter of removing the battery and looking into the circuit with the meter and eliminating components by desoldering or temporarily cutting traces until you have isolated the source of the short.

John

Hi John,

I agree with Michael that to get assistance it would be helpful to post the schematic.  Also agree with John that a multimeter will probably be the most useful tool for trouble shooting.  As for using your oscilloscope for component testing there is information on using the DSOX1102GDSOX1102G to generate Bode plots for capacitors and inductors in the comments below this post.  There is information on using an oscilloscope to determine ESR of a capacitor here.  If you do a search, you will find a number of videos on component testing but I find the videos by w2aew well done.  For example, this one which describes an oscilloscope "curve tracer" and use for resistors, standard diodes, LEDs, Zeners, BJT transistors, etc.

Frank

A photo of front and backside of your device would maybe help. We can help check if something is wrong or if there are possible bridges. Meanwhile, don't put the battery in.

A battery running hot on an AM radio points to a shortcut.

thanks jan

yes i can post pics of back and front.took battery Outland ic also.

have looked on front and back by solders, but my untrained eye fails to pick up anything obvious.

if u see something, let me know.

john

The soldering is good. I see that most of the transistors are NPN. There's 2 PNPs that I can see (Q5, Q7). You have different part numbers for those?

Electrolytic capacitors look correct (I can't see the symbol under C13 but when viewing the schematic, it looks that it's correct too).

The diode is correct too.

I don't see anything obvious.

What is the resistance if you take out the battery and measure over the two solder points of the battery housing?

Maybe double-check if this is repaired correctly:

Also, this bit looked strange:

Is something missing where the red arrow is pointing at a rectangular slot? To me it looks like the switch (marked with blue arrow) isn't connecting, because nothing is connected to that rectangular slot, so power cannot be enabled into the circuit.

It doesn't explain how the battery could be getting hot though! That's the opposite to what would be expected..

Maybe a second photo is needed of the PCB, I just can't tell from that angle.

Looking at the potentiometer, it seems that it has been inserted from the wrong side (inserted from above instead of pushed in from the underside)..

The movable switch part looks forced (blue), and the right connector of the switch is above the PCB instead of below, on the solder pad (red).

The unsoldered contact can't create a shortcut.

But this may be the cause:

Ah, I see, you're right... You mean the switch pole is bent and hitting the shell, right? Yep, that could do it, if the wiper is touching to the shell and the volume is turned down : (

I'm so used (like you probably) to seeing this type of reverse-mounted switch/pot from 20th century consumer radios : ) but I can see it could be a confusing component for any newcomer wishing to solder it on!