there's more to doing voltage testing than can be covered in a single Ytube vid but hopefully the collective here can help steer you through to a good outcome.
i'd still like to get a better look at the pot wiring (and sorry about the comment on your soldering, i get it after numerous tries (37?) even my work would suffer)
at this point try not to succumb to the temptation of doing a bunch of rebuilding/re configuring there's only so many times the lands on the PCB will take resoldering before foils start lifting.
let's go over what you have currently to see if we can't make this thing pass a signal.
so yes friendly1uk i think is making a valid point about the output relays. do you hear them click after the preamp powers up?
from the picks so far it does seem like you've successfully bypassed the original input selector.
relays tend to create "pop's" when switching so i've a reasonable suspicion there may be a Jfet used as a mute left somewhere in circuit that's defeating your efforts.
that's for later though
i'd still like to get a better look at the pot wiring (and sorry about the comment on your soldering, i get it after numerous tries (37?) even my work would suffer)
at this point try not to succumb to the temptation of doing a bunch of rebuilding/re configuring there's only so many times the lands on the PCB will take resoldering before foils start lifting.
let's go over what you have currently to see if we can't make this thing pass a signal.
so yes friendly1uk i think is making a valid point about the output relays. do you hear them click after the preamp powers up?
from the picks so far it does seem like you've successfully bypassed the original input selector.
relays tend to create "pop's" when switching so i've a reasonable suspicion there may be a Jfet used as a mute left somewhere in circuit that's defeating your efforts.
that's for later though
Ah yes. I feel like this is onto something. It makes sense.
Wow, I thought I wasn't really touching circuit. I gotta definitely ow down on my experiments.
I'm heading away for a 5 day ski trip, unfortunately as I'm really appreciating this help...I'll just point out that it's great to get help but it also makes you feel better about people in general when folks are ready to lend an u judgemental hand. It's nice.
I'll learn what I can over my trip and see being up what I don't understand.
No worries, I was literally grabbing wire that has solder on it and tacking it on.
Yeah that's basically what I just kept doing, and trying to use the multimeter to best of my abilities...and was getting nowhere.
That's interesting and makes a lot of sense.
I did, not too carefully, keep the parts. I see no reason I can't put it back in as it was and it should be basically right back to new. It just makes sense if my goal is to get it working and get back to listening to it.
When I get back I'll do that first, as I think it'll be quick and easy. If it works, great. If not, I'm grateful to have other stuff to try due to you folks.
no please don't go swapping/changing things that has not worked so far so doing it yet again isn't likely to get a different result.
we need to figure out what's wrong in it's current state.
go skiing have fun... you'll be in a better state of mind to approach this problem later.
we need to figure out what's wrong in it's current state.
go skiing have fun... you'll be in a better state of mind to approach this problem later.
So I'm feeling happy. I understand your advice about not mucking around blindly anymore but I hadn't actually tried to put the RCA - selection pcb back in, and wanted to test the mute circuit theory...so I tacked it back in and got sound! So I think that must be it. Feels good to think I'll be able to fix it.
My question now is, is it possible to defeat that mute? Without a schematic? The input selection has been janky for years (hard to actually select a specific one). I have a nice quality Elma gold plated selector as used in pass preamps and would prefer to go directly from RCA in to that...if it seems reasonably doable.
The RCA board connects to the main board in the pic below. I'm guessing without that connection it activated the mute?
My question now is, is it possible to defeat that mute? Without a schematic? The input selection has been janky for years (hard to actually select a specific one). I have a nice quality Elma gold plated selector as used in pass preamps and would prefer to go directly from RCA in to that...if it seems reasonably doable.
The RCA board connects to the main board in the pic below. I'm guessing without that connection it activated the mute?
Attachments
that's where seeing the schematic would be best, and it would take having the unit in front of me to say for certain the best way to defeat/bypass the mute.
this is where i should bow out because it would require in depth work that, no offense ,may be above your current skill level, sorry.
this is where i should bow out because it would require in depth work that, no offense ,may be above your current skill level, sorry.
Yeah that's fair, and all I really needed to hear. I won't do it, it's not necessary. I'll put that section back together, put my upgraded volume control in and be rolling again, hopefully.
Appreciate everyone's help very much.
Appreciate everyone's help very much.
Yes, I didn't try to fix it as I wanted to replace the whole section, not for any particularly good reason. I'll clean the rotary selector it's most likely the issue.