Kenwood KR8050 Recap Project - Help with Strange Findings...

[YANIR GVIRTz]

Recently purchased a working KR8050 and decided to recap following the great post of Super Noob (https://audiokarma.org/forums/index.php?threads/project-kenwood-kr-8050.882572/).
Unit is in generally good condition, with no evidence of prior work on PCB's or anywhere else .

However; on the Pre-Amp (X08-1740-10A/G) section I noticed 2 strange things:
1. Two resistors on back side seem non-original work (They were connected to 2 capacitors that I removed, and the whole area seems like it has been worked on - a little sloppy job).



2. Two resistors (R32 and R34) on top have been clipped away.



I can solder, but definitely don't have the electronic background to figure out what is going on here.
Would highly appreciate if anyone could help me read these tea leaves...

1. Any idea why would someone do this?
2. Should I re-install original resistors? Service manual has R32 at 62K and R34 at 100K.
3. Should I remove the green resistors on back?

Please see images attached.
BTW - Super Noob pictures clearly shows R32 and R34 in place on his Pre Amp board.

Thank you!

 

[YANIR GVIRTz]

On a PM yesterday @Super Noob quickly replied:

"If you study one of the under board resistors = looks like it going from one side of the R52 (common to + side of C25) and the other side appears to be running to positive side of C22. What does look like on the circuit.... look like is runs from the same spots as R47 runs? You agree? So likely this is replacement of an open R47.
Would think the other is R46 underside replacement. I have no training in electronics am just curious and patient.

Good luck on this bitch of unit to work on"
​

His remote-diagnosis is 100% correct - as can be seen in this Service Manual diagram:




So I will clean up by removing underneath resistors and install new on top of the PCB in the original locations.

As for the clipped resistors R32 and R34:
Here is the relevant section of the service manual:






Any ideas as for why someone would clip them?

Thank you!

 

[Binkman]

Any ideas as for why someone would clip them?

Lazy.

 

[YANIR GVIRTz]

Lazy.

At the top of my 7 deadly sins...
I have a strong feeling the two resistors soldered below the PCB are there for the same reason - taking out the board is a real PIA...