Intermittent right channel - back again

[orange]

FWIW: I have a 400/II plugged into a power strip with a foot switch. My obese cat hit that footswitch momentarily while climbing into the window. The meters were still pulsing, but the sound was out. A power cycle restored the output, apparently the interruption latched the DC circuit.

Time to move that PL!

 

[NavLinear]

Mouser Part # 677-PCLH-204D1S

Lee - isn't that the part number for the 400 DC protect?

 

[laatsch55]

DAMN!! Sure was Navo...



Gary , here's the right number!! 655-T9AS5D12-48

 

[62vauxhall]

Got it. Revised number is for the 700.

 

[laatsch55]

Yes....

 

[62vauxhall]

I got notification yesterday the new relays were at the border but that was just after I agreed to doing an 8 hour work shift today. So unless I find myself near Sumas WA during the upcoming week, I can't get them until next Saturday.

And don't you know, Murphy inflicted his law again. Although somewhat disassembled on the floor, the amp did not hiccup once in two or so weeks, both channels were lovely. I get home tonight, continue with makin' mahsef a reel tape recordin' of wimmen singin' and the right channel quits halfway through the first cut. No biggie, just had to listen mostly to the left speaker. The right side did return now and then but both meters were continually bouncing merrily away.

Gotta be a relay, right?

 

[laatsch55]

Can you flick the relay and get it to work?

 

[Gepetto]

I got notification yesterday the new relays were at the border but that was just after I agreed to doing an 8 hour work shift today. So unless I find myself near Sumas WA during the upcoming week, I can't get them until next Saturday.

And don't you know, Murphy inflicted his law again. Although somewhat disassembled on the floor, the amp did not hiccup once in two or so weeks, both channels were lovely. I get home tonight, continue with makin' mahsef a reel tape recordin' of wimmen singin' and the right channel quits halfway through the first cut. No biggie, just had to listen mostly to the left speaker. The right side did return now and then but both meters were continually bouncing merrily away.

Gotta be a relay, right?

why didn't you just jump the relay?

 

[WOPL Sniffer]

why didn't you just jump the relay?

Bully

 

[62vauxhall]

Because....unless I can do a 2 wire jump with alligator leads from the red & white wires where they connect to the protect board, directly to the speaker terminals, I have been under the impression the board must come out. Since that would need to be done to re & re relays, I thought I'd do that chore just the once.

These days I've been away from at work 85+ hours over a 6 day week so free time (as in not working or sleeping) is at a premium.

Besides, as I said it is very intermittent. Since yesterday, it's corrected itself within seconds so by the time I take the few steps to the amplifier, the channel returns. In the past, the channel would stay out for longer but that was at a very low listening level. As in playing some music to nod off with on the couch low. On those occasions, turning the volume up a tad brought the channel back, I lower the volume again but it would usually cut out again after a short time.

 

[Gepetto]

Because....unless I can do a 2 wire jump with alligator leads from the red & white wires where they connect to the protect board, directly to the speaker terminals, I have been under the impression the board must come out. Since that would need to be done to re & re relays, I thought I'd do that chore just the once.

These days I've been away from at work 85+ hours over a 6 day week so free time (as in not working or sleeping) is at a premium.

Besides, as I said it is very intermittent. Since yesterday, it's corrected itself within seconds so by the time I take the few steps to the amplifier, the channel returns. In the past, the channel would stay out for longer but that was at a very low listening level. As in playing some music to nod off with on the couch low. On those occasions, turning the volume up a tad brought the channel back, I lower the volume again but it would usually cut out again after a short time.

The 4 speaker output posts come through the board as screws into standoff posts so it is easy to do without taking out the board.

 

[Gepetto]

Bully

That's me Perry...

 

[laatsch55]

i THINK THAT WAS A tEDDY rOOSEVELT-------------------------------------


BULLY!!!

 

[WOPL Sniffer]

You boys is funny today..... excellent.....

 

[62vauxhall]

Just installed the new relays but in the process two wires popped out of the connector strip - a blue and a white.

Wondering if I could impose upon someone to say which wire goes to which terminal?


View attachment 25941 View attachment 25942 View attachment 25941 View attachment 25942

 

[laatsch55]

Need a pic of where the wires go to....

 

[62vauxhall]

Need a pic of where the wires go to....

Thanks Lee. Jerry bundled the wires up nicely so without undoing his handiwork, the wires seem to end here:
-blue spliced onto two greens at bridge rectifier
-white to the power supply filter caps

 

[jbeckva]

Just installed the new relays but in the process two wires popped out of the connector strip - a blue and a white.

Wondering if I could impose upon someone to say which wire goes to which terminal?


View attachment 25941 View attachment 25942 View attachment 25941 View attachment 25942

Ok, so referring back to this pic the blue is actually DC (that's the idea.. the rectifiers are moved way over to the bridge). It goes to the "AC" on the very edge of the phx connector, and the white is the ground (GND) next to it.

 

[62vauxhall]

Thanks Jerry. My shift is over in about 8 hours so home about 2 hours later and will re-connect then.

 

[62vauxhall]

Seems just one of those two phoenix terminals marked AC is "live" and of course I picked the wrong one first as the relay did not engage. Moved the blue wire to the other one and got some action.

But I think I need to take the board completely out.

The problematic right channel came on right away but the left did not. Grasping and twisting the relay restored audio so there seems to be some sort of "mechanical" problem. Might be bad soldering (on my part) but I can't really get a close look at it as the amp sits. It seems logical that removing the board to view under magnification would be the best course of action - yes?

I'll take a picture of where the wires go so I won't have to ask again.

Work weeks for me are 90 hours over 6 days and it's a real bugger trying to fit hobby type stuff into the hour or two I have before getting my 5 or so hours of sleep per night. Eating dinner is usually the first casualty but not today. Tonight's was a mystery meat sandwich then ice cream.