Author Topic: How to test a 3PDT switch  (Read 4228 times)

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How to test a 3PDT switch
« on: July 24, 2011, 09:55:11 PM »
I'm debugging a GGG ITS8 tube screamer I just built and based on help from another thread, I may have a bad 3PDT switch (or I might've melted it when soldering).  I get correct voltages at the IC pins and Q1 and Q2 pins.  I get a by-pass signal just fine to amp, but no led or signal when the switch is engaged.

I've read in other threads to test a switch by using a multimeter on continuity, but I haven't seen a detailed explanation of exactly how to do that.  Like do I need to de-solder the switch to test it or what?

Would someone please be kind enough to help with a detailed explanation of where I should have continuity exactly?  Thanks.


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Re: How to test a 3PDT switch
« Reply #1 on: July 24, 2011, 09:59:30 PM »
Alright so I'm gonna take a shot at this.

There are 9 lugs. Lets say if you look at the switch from the bottom so you're looking at the pins. The lugs should be horizontal. (Hopefully you know what I mean there)...Then you'll see 3 rows and 3 columns. The middle row is always on and what the 3pdt switch does is either connect the middle row of lugs to the top row, or the bottom row. So if you take a meter and test for continuity between the middle row of lugs and the top ones and find continuity in all 3 columns, then click the switch and test with the bottom row and center row.

Does that make sense? Hope it helps.


Re: How to test a 3PDT switch
« Reply #2 on: July 24, 2011, 10:22:35 PM »
Good explanation Elenore, and to further clarify, you don't have to desolder the switch.


Re: How to test a 3PDT switch
« Reply #3 on: July 24, 2011, 11:26:18 PM »
make sure the holes are vertical when testing.

it switches the same as a spst switch, just with more poles.

also, it sounds like if you are getting a clean bypass signal then the problem lies elsewhere.

pics please!