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Positive or negative tip: how to tell?

I have an old Sanyo cassette recorder, model M 1540A. Can find no information on what polarity of tip it uses. Only know that it's 6.0 Volt. No markings on outside of case to show what it is. Sanyo website and customer service has no information and websearches come up empty.

I have opened the unit. It takes 4 "C" cell batteries. The circuit board is old and isn't labeled. I can't tell how the AC adaptor jack is wired to the board. A label on the outside says to use AC Adaptor

6CV120 or 6CV121.

I have two adaptors I am considering using with it, both positive tip. One is a class 2 transformer that outputs 6V DC and 300mA. The other (much bigger)is labeled AC Adaptor and outputs 6V DC and 2000mA.

Any ideas?

Reply to
nobobo
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Check to see which end of the battery stack connects to the PCB "ground" or common (generally, this will be fairly easy to find on the PCB). The "tip" will almost certainly be the OTHER end.

Bob M.

Reply to
Bob Myers

With your ohmmeter put one side to the battery negative connection and check out which of the adaptors poles has continuity with it (possibly the outside). Then you can insert the plug without modifications. You can then try either supply.

--
ciao Ban
Bordighera, Italy
Reply to
Ban

Don't connect the meter when set to measure ohms to a power source! Make sure you're measuring volts instead of ohms.

Mike

check

Reply to
Mike 

--
It would probably have confused the original poster less (and possibly
prevented him from damaging his meter or blowing a fuse, or
whatever...) if you\'d have advised him to remove the batteries before
doing any continuity testing, don\'t you think?
Reply to
John Fields 

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How do you know he can\'t?  Usually it\'s pretty easy, you just stick
the probe in there.
Reply to
John Fields

Read again what I wrote and do not confuse the original poster please. Ban

Reply to
Ban

How can you reach the terminal with the batteries inside? And I want to see the guy that has working batteries in a years-old gadget?

--
ciao Ban
Bordighera, Italy
Reply to
Ban 

--
Ha,ha, you\'re wrong. 
Ban isn\'t an idiot.
Reply to
John Fields

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