PL4000 rebuild

[Overundr1]

These two locations and is the 22k resistor added to the feed line to the bulb or is it somewhere already in the circuit?

 

[Overundr1]

Now to remember how to put it all back together once I get the rca jacks mounted. Every board rebuilt, re flowed and trace verified. Cosmetics done too. Managed to create quite a mess on the bench along the way, oh well

 

[Overundr1]

Ty @marcok for the information. Was able to find the attach point. Verified with leads attached to the pin 8 and where the solder point is. Much appreciated. Looks like when whoever first took this apart marked the spot with a red check mark.

 

[marcok]

Take a look at the interconnect schematic .
It's not easy to find led ( top right )
Ciao
Marco

 

[Overundr1]

Well, after way too long enjoying the puzzle of putting it back together and re cleaning one switch she is working and sounding great once again. Quite a project. Traces on scope look good as well. Thanks for all the help along the way folks.

 

[Overundr1]

Oh btw way very early version serial number 894.

 

[laatsch55]

ALL the bugs should have inhabited that one....

 

[George S.]

Very nice! That one won't need any foam block between the vertical boards and cover.

 

[Overundr1]

Only bug was trying to understand why joystick left to right was working top to bottom (DOH) turned it 90 degrees and easiest repair of it all lol.
In other news have an original PL-700 inbound this week. Will be a challenge.

 

[mr_rye89]

These can be WOPL'd but require a new chassis.

 

[laatsch55]

Lee, I'll get off my dead ass and get that 4000 headed your way...

 

[laatsch55]

Sorry for the delay..

 

[Overundr1]

Thinking the buss bar mod, esr the main caps, hfe check and remount the outputs, go through the control board as a starter. Been told unit does power up and only faint output with static. No problem sir, you are doing me a favor. Now how to handle this sudden Phase Linear affliction I seem to be smitten with lol

 

[laatsch55]

It can happen....

 

[Overundr1]

Last picture. All functions quiet and operate correctly. Wired to my QR4500 cap coupled quad receiver through the pre/amp jacks in 4 channel mode. Sq mode is sublime. Thanks for the help along the way.

 

[marcok]

Glad to help you .
Ciao
Marco