• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Harmon Kardon 430 preamp and pb switch removal anyone?

R

rickcl

New Member
Hello all, I have a Harmon Kardon 430 that has a short to the left signal wire. I believe the problem to be around the switch board. It does not look like the pb switch board or the preamp board can be accessed without removing the front panel. I wouldn’t mind but the front panel involves removing the tuning dial cord! I don’t think much thought was given to servicing. In the many videos online I can’t see one that gone this deep. Has anyone?

Thanks all, Rick
 

Attachments

  • E9BC99AB-5C66-451E-A0A1-91348298308D.jpeg
    E9BC99AB-5C66-451E-A0A1-91348298308D.jpeg
    155.8 KB · Views: 11
  • 5F8F0D2C-8F15-4AF6-966A-462399807471.jpeg
    5F8F0D2C-8F15-4AF6-966A-462399807471.jpeg
    248.4 KB · Views: 7
  • 43B9537E-770C-44DA-861B-FCF9D63DE446.jpeg
    43B9537E-770C-44DA-861B-FCF9D63DE446.jpeg
    216.6 KB · Views: 7
Last edited:
Register to hide this ad
rickcl said:
Hello all, I have a Harmon Kardon 430 that has a short to the left signal wire. I believe the problem to be around the switch board. It does not look like the pb switch board or the preamp board can be accessed without removing the front panel. I wouldn’t mind but the front panel involves removing the tuning dial cord! I don’t think much thought was given to servicing. In the many videos online I can’t see one that gone this deep. Has anyone?

Thanks all, Rick
Click to expand...

I don't think that is correct, having to remove the tuning dial cord. I've serviced a fair number of those and don't remember that, something it seems like one would remember for the oddity of it. As an aside, you should either diagnose that as the problem or possibly cleaning the switches with control cleaner as that might be what it needs.... it might not be a short but an open at one of the switch contacts which cleaning might fix.
 
I would like to hear how you did it. Please take a look at the new file I uploaded and it looks like a tough job to get it to swing away to access it. The signal it shorted to LP514 on the preamp board. Balance pot removed. I think it might be the contour switch.
That switch board has has no lee way.
 

Attachments

  • 192B52EE-07DC-4B33-BF9E-113790E6454B.jpeg
    192B52EE-07DC-4B33-BF9E-113790E6454B.jpeg
    152.3 KB · Views: 16
rickcl said:
I would like to hear how you did it. Please take a look at the new file I uploaded and it looks like a tough job to get it to swing away to access it. The signal it shorted to LP514 on the preamp board. Balance pot removed. I think it might be the contour switch.
That switch board has has no lee way.
Click to expand...

It's been years and can't remember. Looking at the picture it is tight, looks like you might want to remove the board next to it too, might have to remove a few wires, take pictures. I'm not looking at a schematic but you seem sure of your diagnostic... the contour switch, that would be loudness compensation, maybe an associated capacitor shorted, sounds like you've reasoned it out. Thinking out loud here... there is no way I'd remove the tuner dial cord to get a board out... but then I'm not looking at it. It's just that I've never seen that necessary and I've had many units of that era apart. I'm hoping for some one with recent experience with that unit to come in... those are nice sounding units.
 
Yes thanks for the reply. I pulled the function switch out to inspect and the short has stopped. I think it might be in the many mini shielded leads they have here. I will reassemble and test. I ruled out the contour switch. All it does is short a cap to ground on the preamp board. It has no connection to the signal path.
 
I use to sell these when they were new! Tried to tell people about the dual transformers but many didn’t get it.
We also sold Technics SL-1200 for 399.00 including a Stanton 681 cartridge.
 
rickcl said:
Yes thanks for the reply. I pulled the function switch out to inspect and the short has stopped. I think it might be in the many mini shielded leads they have here. I will reassemble and test. I ruled out the contour switch. All it does is short a cap to ground on the preamp board. It has no connection to the signal path.
Click to expand...

Ahh... no connection to the signal path. Well, if it quit indeed something is shorting out, not a component failure. Reassemble and poke around with a wooden or plastic stick to see if it either comes back or goes away... would be nice to find the problem so you know you eliminated it. Also a solder bridge or a hair line crack on the board.. even a cold solder joint, thinking it might not be shorted signal, rather an open. Anyway, sounds like you are close...
 
rickcl said:
I use to sell these when they were new! Tried to tell people about the dual transformers but many didn’t get it.
We also sold Technics SL-1200 for 399.00 including a Stanton 681 cartridge.
Click to expand...

I remember that from the sales floor... the HK units had to be sold on merit because they lacked the 'flash' of many other units. I always thought they had understated eloquence, classy functional look.
 
You must log in or register to reply here.
Back
Top Bottom