Phase Linear 700-II repair advice needed

[NavLinear]

heh, yeah I found that out.

Vaguely related, but does anyone have a suggested source for replacement input RCA jacks? I just tried to plug in a turntable to test this, and one of the jacks fell apart. Looks like the stock jacks are a shorting design. No clue if they are anything approaching a standard unit or if its pure unobtanium 1970s stuff.

I have not purchased from this seller but he has a couple of scavenged input jacks from a PL 4000 for sale.

http://www.ebay.com/itm/Phase-Linea...pt=Vintage_Electronics_R2&hash=item1e78b0c320

 

[gadget73]

I stole one from the rear channel for now so the phono input works. I'll ask my friend if he wants it fixed fully and pick one up then. Thanks for the link.

Also found a few more bad solder joints when I changed the phono jack. I think I have the tone controls responding correctly now, and if I hit the Correlate switch, it doesn't just shut off the left channel anymore.

 

[NavLinear]

The 4000 is notorious for cracked solder joints on the mother board (MB) as it has little support and when a board is installed and pressed into place it can stress the MB. In many cases reflowing the MB joints will fix this problem.

The board connectors are not gold plated and over time there is a tendency for oxidization, New connectors with gold plated contacts are available that could be substituted providing a better interconnect.

Of course there an ass ton of electrolytic capacitors and considering the age of the preamp one might want to replace those also.

 

[laatsch55]

heh, yeah I found that out.

Vaguely related, but does anyone have a suggested source for replacement input RCA jacks? I just tried to plug in a turntable to test this, and one of the jacks fell apart. Looks like the stock jacks are a shorting design. No clue if they are anything approaching a standard unit or if its pure unobtanium 1970s stuff.

The only real fix for that is mounting aftermarkts and running wires to the board..

 

[P.L.F.]

Check again the 700 II Service Manual for troubleshooting details and you may have a look here too: http://www.audiokarma.org/forums/sho...293316&page=17 -> specifically see post #245 and it's attachments.

When you decide doing so, put in the driver first (originally RCA-410's) and bring it up on the dim bulb. A dim bulb tester is a must. A variac will limit voltage, but not current. If everything is fine with drivers installed, put in another row (power outputs) all the way accross, then power on with dim bulb again, then another row accross, etc. Get the bias set close as possible on the first row, but you'll have to adjust it as you go.

I've just realized that some links don't work. Attached is Phase Linear 700 Series II repair guide, which I posted some years ago...

 

[P.L.F.]

I've just realized that some links don't work. Attached is Phase Linear 700 Series II repair guide, which I posted some years ago...

This one should work: https://forums.phxaudiotape.com/med...700-series-ii-restoration-advice-updated.278/ ...