Dual 500 issue...

kingman

Journeyman
Joined
Mar 22, 2017
Messages
93
Tagline
---
#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

Veteran and General Yakker
Joined
Aug 13, 2014
Messages
2,762
Location
Vancouver
Tagline
---
#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
 

Attachments

Last edited:

kingman

Journeyman
Joined
Mar 22, 2017
Messages
93
Tagline
---
#7
Thanks! I'll play around with it after the holidays. Right now just listening to a few tunes on it. :headbang:
 

oldphaser

Chief Journeyman
Joined
Sep 8, 2012
Messages
845
#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
 
Top