HOW TO POWER A CIRCUIT BOARD OUT OF CHASSIS FOR OSCILLOSCOPE TESTING.

[EDWARDEFFECT1]

I WANT TO BE ABLE TO TAKE THE CIRCUIT BOARD OUT OF AMPS WHEN I WORK ON THEM AND BE ABLE TO POWER THEM UP FOR SIGNAL TRACING WITH AN OSCILLOSCPE AND NORMAL MULTIMETER TESTING WITH THE BOARD OUT OF THE CHASSIS SO THINGS ARE EASIER TO MINIPULATE.WHAT  EQUIPMENT DO I NEED TO ACCOMPLISH THIS.THANKS!

[J M Fahey]

1) A good pair of reading glasses.
If you need TO USE ALL CAPS IT MEANS YOU WILL NOT BE ABLE TO READ PARTS VALUES.
2)
It depends on the board.
Basically all connexions will need to be made through longer wires.
Most amps are wired as to allow flipping boards upside down or at least by 90 degrees, to allow access to the other side.
A few even offer "access windows" in the chassis, to the same effect.

[EDWARDEFFECT1]

thanks for the idea about the longer leads.i was thinking i would have to buy a dual ac power supply or something as such.i am going to make some leads up right away.don't know why i didn't think of it. sorry about the caps. i have to break myself of a bad habit.thanks for answering my post and being so considerate about my capitals...i have a post about checking capacitors in the newbie section.could you help me with a how to proceedure on cap testing. electrolytics....thanks for all your help....ed!

[J M Fahey]

Ok, please be somewhat more specific, post some picture or make a hand drawing to clear things.
Generally speaking (and with lots of exceptions), many wires can be lengthened , say, 10 to 20 inches without problems.
Ground wires should still be connected to the original points.
Be careful with low signal level wires.
Maybe a bare wire (or plastic coated) *can* be used on the original connexion, if only one or two inches long, yet that same one using a long unshielded wire brings trouble.
Just think "¿what if ... ?".
When pulling the board for measurement, sit it firmly on a piece of wood or some other insulating material 8even a couple magazines).
One of my horror stories is the board slipping and touching chassis among sparks, a big no no.

[Enzo]

I am a professional technician, I work on this stuff all day long.  I have to say that getting board extensions is really working extra hard to take the easy way out.  I almost never extend a board from its chassis.  I will free them from their mounts and flip them over onto a towel or something if I need to get at the far side while running.  But mostly I operate with the boards in place.

If I need to get at the pin of some socket that is covered, I look for the components that connect to the socket pin.  There is bound to be a resistor that goes where you want to be.  So I find R123 or whatever and probe its lead.

The only times I need an extender are instances like a little DSP card covering the area of the main board I need to service.  Or card racks where several boards are lined up side by side.

[EDWARDEFFECT1]

thanks enzo for the extra tips.i have alot of circuit board that i can't get on the capcitors with anything as the solder terminals are on the underside if the board and the capacitors are tight to the top of the board.would be nice to test them with the board in place, then cut off the leads of the component and bend them straight up with a pair of pliers, so that the new component could be soldered to the wire legs sticking up.this would make it a repairmans dream.quick and easy....thanks again! i really respect your posts along with all the others that have helped me.i don't want to list their names here as i might forget one.i appreciate everyone that has helped me. i hope sometime i can help....thanks learning everday.....ed!!!

p.s.  enzo love to stop in to your shop in michigan and watch the whole trouble shooting process and possibly change a few components and help you out for a day as i learn form you.my sister lives in michigan and i go out to visit usually once a year every other year.... i'd love to,but i probably would get in your way!!thanks....ed!!

[Enzo]

Perhaps you missed my suggestion.  That cap may be hard to get at, but its terminals connect to other things.  SO if I cannot get at the lead of a cap directly, I look in the schematic for the resistor or transistor or whatever that connects to it.  I then can connect my probe there.

[EDWARDEFFECT1]

thanks again enzo.if you keep helping me out i'll soon know how to fix stuff in a professional way.i have the equipment,but knowledge is wisdom........thanks...ed!