Infamous Kenwood KR-9600 in Protection mode.

[Conspheracy]

C-7 looks like it's really sick!...

That one is on the list to be replaced, im thinking thats where the problem initially began. C7 probably blew and leaked its fluid onto the surrounding areas. I havent pulled the Supply Board yet to check voltages on the nearby capacitors but ordered replacements for all in that area except C22 which I missed for some reason. I may not even need to replace them but I figured since they were exposed to the fluid it might be easier to just desolder, clean up the board and replace in the long run.

When I go to desolder and replace the components would it be easier to take the wires off their posts, label them, and remove the board completely or attempt it with everything still connected?

 

[Binkman]

would it be easier to take the wires off their posts, label them,

Wire wraps require special tools to do the job...
https://audiokarma.org/forums/index...wire-wrap-dos-and-donts.969034/#post-15002387
Yes label the wires.

 

[Binkman]

Don't forget to take reference pics and make note of the polarity of caps. Please build the Dim Bulb Tester.. to assure your work is correct.

 

[GOYA]

Some might disagree but I find it easier to unsolder the wire wrap posts from the PCB when possible. Pictures and labeling are a great idea.

 

[Conspheracy]

Wire wraps require special tools to do the job...
https://audiokarma.org/forums/index...wire-wrap-dos-and-donts.969034/#post-15002387
Yes label the wires.

Alright good to know haha I did a quick read through that thread and that saved me a wicked headache down the line I’m sure.
Parts should be in tomorrow, I’ve still got some work to do with renovations around the house but if I can find the free time to start working on replacing these components in the next two weeks I’ll be sure to build the dim bulb tester before testing. If all goes well with the replacements on Power Supply A I’m going to be moving over to the B board to replace the transistors and upgrade the resistors as I’ve noticed the unit was getting pretty toasty when it was working.

 

[Conspheracy]

These are the parts that should be arriving tomorrow. The capacitors I was able to find easily, there was one damaged 68ohm resistor that I could not find in stock until March/may 2022 and the closest I could find to run in series that were in stock was a 33 and 39. My only other concern was the transistor as the original is discontinued. I searched a transistor thread and found the one I ordered to be a replacement listed but have seen others listed in other threads on AK

 

[Binkman]

there was one damaged 68ohm resistor that I could not find in stock until March/may 2022

Perhaps pull and do a dmm check on that resistor and see if the lead is corroded or just has cap goop on it

 

[HifiChoctaw]

Hey

Not too sure if anyone will respond back to this thread but figured I'd start to update again. Life got very busy for me shortly after making this thread and the project to restore this unit got pushed to the wayside with home renovations and work. Would really like to start this project again as most of the renovations have come to an end and I would like my family to be able to enjoy getting some use out of this unit.

Currently I've got replacement capacitors and diodes for the power supply board ready to be ordered but im having some difficulties trying to identify the resistors and compare them in the parts list. The service manual only lists four resistors and the four I have listed for replacement are not among that list. I'm attempting to identify the colors and replace the resistors that way but the pictures of the replacements on Mouser dont have the same colors (is this because they use a stock image for their resistors?) One of my struggles is identifying the top resistor in image Kenwood 2, it appears to be two blue lines but they are different colors, a dark blue and a sky blue?

The other issue im running into is finding a replacement transistor for Q6 - 2SA733. When I search for similar transistors it comes up with KSA128YTA. I found this thread https://audiokarma.org/forums/index.php?threads/transistor-substitutions.688515/ which shows a few possible replacements as well. KSC945CYTA & KSA1013YTA were the replacements i was looking into but im not 100% certain which would be suitable replacements.

I appreciate any further input from you all and look forward to hopefully getting some time to start replacing these components. Thank you.

Conspheracy..glad you made it back..wasnt long ago i was reading this thread and wondered what had happened...glad you got back after it..I too am going through another 9600 I just got to add to the collection..I have a working one right next to it,which is helpful...Best of luck and Im eager to see you get it going..and happy to share anything I can...Im a Volvo mechanic but have been working on my gear for a long time..still learning though..which is good .

 

[oldvinyldude]

The plan as of now is to get a decent soldering iron, solder, some good electrical flux, as well as some deoxit and start methodically taking this apart for repairs and cleaning.

I would go with a good soldering iron-not all soldering irons are the same, even though the wattage is equal. I only use mine on occasion (I bought a Hakko), but it was SO much better than what I had before-it was worth the 5x price over the ones I had.

You will also be desoldering as well. I had lots of frustrations with using solder wick. I bought a desoldering iron-it's tip has a hole where the lead can go into when pressed onto the solder joint, allowing the tool to melt down to the board, and then the spring loaded vacuum is released, sucking most if not all of the solder away quickly. If, in the future, I ramp up and do lots of this work, I might spring for a similar tool, with a motorized vacuum-put tip on joint, wait till solder is molten, then press a switch, and boom-solder gone-neat!

I am far far from an expert, but I have solved a lot of issues with patience and a willingness to walk away before I damage something. Just last night, I reassembled a motor unit into a R2R after replacing a belt. I had one screw left over Sometime later that evening (in bed), I remembered where it should go-lol.