Crumar Musical Instruments User Group.

Hi,

I don\ufffdt have a Bit One, but check Pin 4 of the TL072 against ground and
even Pin7 against ground. Me thinks that the TL gets maybe ground onto
Pin4 or Pin7, or some voltages are missing (Pin 4 should have a negative
voltage, pin7 a positive, -maximum- at +/-18 Volts!) and that causes the
overheat. Check for some chips called 7805/78L05 /
7812/78L12/7815/78L15/7905/7912/7915 and measure their outputs. Those
componets have three pins and usually a heatsink installed. Left pin ist
the VCC input, middle is usually ground, right pin is the output. A 7805
should output a fixed voltage of 5 Volts, a 7905 a -negative- voltage of
5 volts, a 7812=12 Volts positive etc. Same goes to the other "78" and
"79"-Chips. Even check their middle pin against case ground, maybe they
get from somewhere voltage where they shouldn\ufffdt.

Greetings
Stef


neurokrash wrote:

>Update
>
>CEM3328 1-bad, 2-bad, 3-bad, 4-bad, 5-working, 6-bad
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>Lower making warbly noises coming from voice 1 circuit TL072ACP which
>is incidentally about 500 degrees and burned the dickens out of my
>finger.  When cooled with compressed air or freeze spray, it quiets
>down, No Noise generator audible
>
>Any idea why this component would be running so hot?
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