Hello anyone. Quick question I removed the complete assembly in order to restore the unit. I then re-assembled all components, yet I cannot get the unit to power up. Any suggestions? Do the 4 transistors have to be put in exactly in the receptacles that they were originally in? Also as for the power switch... Where do I connect the AC power leads to? Any help would be great. I have looked at the schematics and I am pretty sure that I have the black and white leads going to the switch and to a ground source. I am getting 122 volts at the power leads but still no power to the unit. Thank you for any help.
the four main output transistors shouldn't need to be put in any order. they are all 10003 or 40411 transistors.
as for the power switch wiring.. can you give us a close up picture of the wiring near the power switch? I can't quite tell what is going on in that picture.
12-17-2014, 01:59 AM (This post was last modified: 12-17-2014, 02:22 AM by 70spbase.)
Thanks for your reply. Here are the pics. Any help would be great. By the way the (grey wires) are for the bypass of the power amp and are switched via an on/off switch mounted to the original fuse location. The speakers are wired to the leads as originally made by ampeg and then a wire is run to the switch to run the cab as speakers only.
In this pic you may be able to see that the black lead from the power cable is attached in the orange twist cap with a lead from the fuse and a lead from the power switch. The white lead is soldered to the post and the other end of the post has a lead from the light (which doesn't light up) a lead directly from the transformer and a lead from the power switch. The solder looks old and factory soldered. Yet I believe the fuse assembly has been changed as the original should be flush mount to the panel?
Here is a closeup of the wiring from the fuse end and the transformer and light. Not sure if this is factory but it is not indicating any power.
So what is the switch doing exactly? I understand that you want it to allow for normal use with the internal amplifier and as a standalone cab, but how is that accomplished? What kind of switch is it? What are you switching?
Let's tackle that first, then i will tell you what I see beyond that.
12-17-2014, 12:57 PM (This post was last modified: 12-17-2014, 01:02 PM by 70spbase.)
(12-17-2014, 12:11 PM)Hangman Wrote: So what is the switch doing exactly? I understand that you want it to allow for normal use with the internal amplifier and as a standalone cab, but how is that accomplished? What kind of switch is it? What are you switching?
Let's tackle that first, then i will tell you what I see beyond that.
Well that was how I received it, so I can only tell you what the seller told me. The switch acts as a bypass that turns off the signal to the speakers from the amp and switches to speakers only via the 1/4" jack located above the power switch. That way, if the amp isn't loud enough, one can utilize just the speakers. That is how I've been using it since February. Now I would like to use it as originally designed. I have attached a photo of the switch connection. Thanks for your time.
By the way the Yellow tape wrapped around the grey cable is the main lead off of the speaker feed from the mains.
hmm... that switch looks like its a rotary switch. is that right?
I think you should disable it. whoever did it wasn't thinking. You can't just have the switch connect the 1/4 jack to the input of the power amp or the speakers. because the speakers are still hooked up to the amp.
if you really want to have the switch you need to have a switch that also removes the amplifier from the speakers.
for the time being, i would disable it.
as for why it doesn't turn on... The white wire coming in from the power cable goes to that terminal board, but I can't see anything else connected to it. am I missing something?
12-17-2014, 08:43 PM (This post was last modified: 12-17-2014, 08:53 PM by 70spbase.)
I do agree to disconnect the switch. It is not rotary it is a plastic switch similar to the on/off switch on flashlight, the white wire is going to that post and the black lead is connected to that orange cap and the SBT power switch lead and the fuse lead which is also connected to the tranformer
Should the black wire also go the other sude if the terminal? The fuse lead?
