PL700 Rebuild

[Gepetto]

Like this?
View attachment 84119

Yes, that is what it says in the middle of each device on the diagram...

 

[Overundr1]

Think I need better close em up cheaters

 

[Gepetto]

Think I need better close em up cheaters

It is a PDF Lee, no cheaters needed, just zoom in on the document as I did to get you this snippet

 

[Overundr1]

Transferring wiring notes to output diagram. Will need to verify multiple transistor ties while attaching new wires of course.

 

[Overundr1]

Differences noted for right channel of course, those cross board jumpers now make perfect sense, how elegant.

 

[Overundr1]

Wiring complete. Time to spot any errors. Note the final image I have not dressed the wiring yet as was just setting up the orientation.

 

[Hexis22]

Still need a wire placed between control board Phoenix connector 5R and the buss bar.

 

[Gepetto]

Still need a wire placed between control board Phoenix connector 5R and the buss bar.

And if and when you do that, remove the ground bus wire on the back side of the board assembly. The separate ground wire from 5R to the bus bar will serve that purpose.

Leave the 2 upper power bus wires in place however. Just the lower ground bus wire.

 

[Overundr1]

Will do

 

[Overundr1]

Change made. Will go for initial power up and testing without outputs installled tomorrow.

 

[Overundr1]

And proper wire trimming

 

[laatsch55]

There's a bunch of it. .

 

[Overundr1]

easy to trim, hard to stretch

 

[Sunnbobb]

On the units I've restored, I've gone ahead and replaced the 10W resistors on the back plane. Every one I've replaced has been out of spec. Just a thought.

 

[Overundr1]

Slow and ready as she goes. Took a minute to figure out that the heatsinks are directional, installed first row of outputs from right to left (transformer to input jacks) mj21196/rca66546/mj21196/rca65546 along the bottom row using silipads rather than mica and grease. verified no shorts collector to ground.
Went through the entire backplane once more looking for any metal fragments and checking for possible contact point interference, found the second cold solder joint on one of the emitter resistor tie down points and re attached. Re routed the input wiring to run along the side of the unit next to the speaker relay. Left side done, out of time for the day. Will mount all the TO-92 heat sinks once the right side wiring is done just before start up on the dbt. Getting real close now.

 

[Hexis22]

Don’t forget to place heat sinks on the TO-92’s.

 

[Overundr1]

Wiring finished, heat sinks installed. Need a final look over by the distinguished panel before I hook up the Variac and my DBT tomorrow.
Have the initial test/startup instructions from WOPL printed and will follow exactly.
Will say this has been quite the project

 

[Overundr1]

Quick update. Since this is a first year pl700 the output transistor numbering is different of course. Rewiring now stay tuned for results once I finish the other side

 

[Overundr1]

Once I get things up and running need a suggestion for the power and over temp lamp assemblies along with the attendant turret bar that attaches to the faceplate. The original is doa and so is one of the bulb leads.

 

[Sunnbobb]

I'd Replace these. You can see the right one has a bulge.. These are where one tests for bias.