Discussion in 'Kenwood-Trio/Kensonic-Accuphase' started by tusntuk2, Aug 10, 2017.
Pin 4 problem should be bad resistor (RK2 open) or bad solder joint or crack in trace.
Thanks, Steve! I will check it soon. Funny how life happens while you have other plans...Meanwhile, I finished recapping the audio and power supply of the second 5600, and Holy Smokes! This machine has more power than I ever thought, and now it's sparkling clear, too. And I thought the recapped Pioneer SX727 sounded good - well, it does, but the Kenwood seems to overlap the bass and the treble with more range and more specfic (accurate?) control. Such an engaging hobby! You get to challenge yourself with new things while improving your old favorite things, which benefits your most favorite thing, music. Once again, many thanks to the kind folks here in this forum and all who offered guidance to restore this receiver. When I learn how to format a BOM for Mouser I will contribute to the library.
tusntuk2, I also have a my original untouched KR-5600 with a Dual 1228. I have just started setting them up so I checked the receiver first to see what worked. Powers up, lights and meters work, AM and FM work. Hooking up the turntable regardless of phono A or B and Aux, I get no sound. I plan to take my TT somewhere to insure it is sending a signal to receiver. Hopefully I can get this sweet little hot rod cranking as well as yours That's just where I stand now, but what I am really interested in is following your recap project, your pending BOM and most importantly hoping you will upload your KR4600/5600 service manual. I have spent the week reading through AK site and very impressed with the concise information and quality of the members.
Good luck with your project onehander! You may want to start a new thread to help find the answer to the lost phono/aux signal. There could be many causes, and I am not an EE, just a retired musician with a hobby interest in old amps. The KR-5600 uses op-amps in the preamp section, of which I know nothing, so ask those who do. It is also recommended you thoroughly clean the controls and switches and inputs with deoxit, it can solve mysteries sometimes. I was told not to deox the little button switches (top row) in the glass.
As for the BOM, I am working on it, but with two caveats - first, I only swapped electrolytics in the PS and the Audio boards, not the muting or FM boards, and not the preamp. Secondly, Trio/Kenwood made several changes to their receivers throughout this period, some documented, some not, and even in my two receivers there are different PCB's. So this makes it hard to create one BOM that will fit every KR-5600. I will try to list what I did, and for what model boards, and that is the best I can do. The list will need more contributors. There is also considerable discussion about sizing and fitting different main filter caps, so look around AK for that.
Finally about the service manual. It has been noted hifiengine et all lack this manual. I took a chance and paid for a "manual" from a foreign supplier, and I got a good listing of bias adjustments for many models, and a better copy of the schematic, with several models of the small PCB's. I was disappointed for as much as I had paid, but the good schematic did prove useful. i would be happy to share the s/m with you, and the bias is 40mv.
Good luck with the project, and welcome to AK!
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