Ampeg SVT-6 Pro No Output

[ca7922303]

I was thinking the .8mV at J32/J33 was the DC there. It would be better if more details were noted.
R110 and R111 voltages should be close to same. Seems R110 voltages (and R4) are off.

Also, DC voltages should be measured without signal.

Here's the schematic notes about j32/33 I was going by.

[ca7922303]

With signal thru power amp in, across J32/J33(60vdc). Had a dummy load in speaker output Jack and it melted solder off of dummy load and now have a hum. Now with signal in front input jack, across J32/J33(-60vdc)? Not sure what's going on. Nothing has been done except power on this morning?

[ca7922303]

With signal thru power amp in, across J32/J33(60vdc). Had a dummy load in speaker output Jack and it melted solder off of dummy load and now have a hum. Now with signal in front input jack, across J32/J33(-60vdc)? Not sure what's going on. Nothing has been done except power on this morning?

Now J32/33 across(-97mv) signal thru power amp in
(7mv) signal thru front input. Also, running a mp3 thru power amp in is louder now than previous by quite a bit. Could intermittent relays be the cause?

[ca7922303]

Showing readings with signal thru power amp in Jack.

[ca7922303]

Also, Ch. 1(+) half w/signal thru power amp in jack (19vdc)
Ch.1(-) half w/signal thru power amp in jack(19vdc)

[ca7922303]

Mp3 signal thru power amp in jack is clean now, even with tube gain on full.

[nevetslab]

With signal thru power amp in, across J32/J33(60vdc). Had a dummy load in speaker output Jack and it melted solder off of dummy load and now have a hum. Now with signal in front input jack, across J32/J33(-60vdc)? Not sure what's going on. Nothing has been done except power on this morning?

This amp continues to be unstable and unreliable, with DC levels changing from no offset to now +/- 60VDC potentials. Your output relays appear to have passed that DC level on to your load. I hate to say it but you really should take this to a competent amp tech and get it fixed. From everything I've read thru this thread and tried to follow with your efforts, I don't trust the amp in the state it's in. Sorry.

[ca7922303]

This amp continues to be unstable and unreliable, with DC levels changing from no offset to now +/- 60VDC potentials. Your output relays appear to have passed that DC level on to your load. I hate to say it but you really should take this to a competent amp tech and get it fixed. From everything I've read thru this thread and tried to follow with your efforts, I don't trust the amp in the state it's in. Sorry.

Appreciate all the help. Thanks.

[ca7922303]

I was thinking the .8mV at J32/J33 was the DC there. It would be better if more details were noted.
R110 and R111 voltages should be close to same. Seems R110 voltages (and R4) are off.

Also, DC voltages should be measured without signal.

I am removing relays now and will attempt to see if they work. Looks like they are bad but will check them to be sure.

[ca7922303]

1st relay I have removed seems to be stuck open. Reading (0.00) ohms across pin 1&4 unenergized. Will order two(2) new relays meanwhile while I continue testing.

[ca7922303]

Haven't removed 2nd relay yet, but in circuit, it is reading (0.00) ohms across pins 1 & 5. Guess it's closed. Looking like these relays are not going to be easy to find.

[g1]

Relay pin1 should be zero ohms to pin5 when not energized. When energized pin1 should connect to pin4. So at least one of yours is definitely bad.
HF115F-A 024-1ZS1 will be good sub. (ebay)

[ca7922303]

Relay pin1 should be zero ohms to pin5 when not energized. When energized pin1 should connect to pin4. So at least one of yours is definitely bad.
HF115F-A 024-1ZS1 will be good sub. (ebay)

Thanks for the referral. I'll order 2 and post when they're installed. Appreciate it..

[ca7922303]

Looking at a previous svt-6 pro on the forum, found some components not @ spec. D4(.10/.10) diode test, R16(10k) ohms, R17(75) ohms and R148(OL). Will order these and continue checking around.

[ca7922303]

Installed R148(100 ohms), R16/17 are good out of circuit, reinstalled, D4(.10), D33(.13) diode test in or out of circuit. May change due to every diode on board is around (.5 diode test) except those two(2).