Dual 500 issue...

kingman

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Joined
Mar 22, 2017
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89
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#1
I know there was a thread related to the 500 turning on by itself independent of the switch but can't find it? Can anyone direct me? Also looking to replace the large caps. . Suggestions? Thanks!
 

grapplesaw

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Aug 13, 2014
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#4
I know there was a thread related to the 500 turning on by itself independent of the switch but can't find it? Can anyone direct me? Also looking to replace the large caps. . Suggestions? Thanks!
The power caps are 12,000uf 120 volt 3” by 5.5”

if you want a nice upgrade Apex jr has some 33,000uf which I am using. Need to upgrade the bridge rectifier as well

the 500 uses a relay to turn on or off. The power switch runs through the front panel and powers on the relay circuit. There is a small transformer behind the meter panel to operate that system

power on and offf are controlled by transistors that may need replacing. A power outage ( external or internal) may activate the circuit and be your problem. A simple fix is a power strip with switch

please read the service manual as it describes this better and possible repairing it . The problem is in the meter board or power supply for it, no othe way to turn on or off than there
 

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kingman

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Mar 22, 2017
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#7
Thanks! I'll play around with it after the holidays. Right now just listening to a few tunes on it. :headbang:
 

oldphaser

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Sep 8, 2012
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720
#8
Wayne,

You may have a problem with a MPSA42 on the meter drive board. You may also want to check the capacitors as well.

Ed
 
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