Super Eleven II issues, please help

moondogtn

Well-Known Member
All, I need some help. Here is all information.
My father in law had a super eleven he wanted repaired and asked me to look at it. It powers up, most lights work which are positives, no relay click and no sound are not good.
I have checked power supply board using pin 5 and ground and the following are readings I got
Pin
1. none
2. 38.4
3. none
4. 38.4
5 thru 9 no voltage
10. 7.4
11. 7.4
12 thru 18 no voltage
19. 6.27
20. None
21. None
22. 6.0 volts

Pins 19 and 22 begin at approx 2.5 volts and after about 2 seconds they jump to 6 volts. i don't know exactly what to look for and was hoping someone could point me in right direction. Thanks

Bill
 
Meter settings? Seems you only show the AC voltages, so I'm gonna guess that you had your meter set to AC for everything.
 
Doh!!...I should have known seeing the -51 that it would have been dc but I am a little rusty. I went back through documentation and verified the dc voltages. Thanks for not making that sound worse than it was.

1. -60.5 VDC
3. 51.6 VDC
7. 8.7 VDC
8. 8.7 VDC
12. 34.27 VDC
13. 21.07
14. 13.82

Maybe this will help steer me in the right direction.
 
OK...DC voltages on the collector, base, and emitter of Qk1 and Qk2 on that same board.
 
OK, so I checked the voltage on those transistors using chassis as ground. Are those the voltages you were looking for. Service manual I have is not very clear. I am looking for another source that will hopefully be more legible. Should I just remove them from board to test? I have a junky little soldering iron here but not variable so I am hesitant to use on circuit board. Let me know what you think. By the way, thanks for the help!

Bill
 
Yes, we want the voltages with the negative meter lead on the chassis.

Now, do the same with Qk3 and Qk4. We have no voltage on the base of Qk1, and that means either Qk3 or Qk4 is 'on' and shorting the base to ground, or we have some bad parts that won't allow Ck12 to charge (Ck12 bad, or Ck11, or a open resistor).

I do not have the manual for this one, but I do have a readable schematic. I'll send it to you if you PM me with an email address.
 
I received the schematic. Thank you. I haven't had a chance to look over them yet. I will try to check the components you mentioned. Thanks again for the help.

Qk3
B 1.0 VDC
C 0.0
E .185

Qk4
B .29 VDC
C 1.038
E 0.00
 
Last edited:
OK...looks like NONE of the transistors are on, DC offset is appropriately low, so we more than likely need some new caps on this board. The offenders are likely Ck11 and Ck12, but if I was going to do this I'd replace all the caps on the board. It's possible that there's an open resistor, but while you're in there you can look 'em over.

Don't forget, Ck11 is a non-polar cap.
 
I removed both caps and checked using meter. I'm reading meg ohms and they are increasing?? Both caps do this. I would say they are both faulty but as you said it would probably serve well to just replace all caps on this board. I think there are only 7 total. I haven't looked at any resistors yet. I just wanted to post this and keep you updated. By the way, what is the best way to get this card out to work on these components or should I not remove it??? Thanks again.

Bill
 
Last edited:
Never worked on one of these, but (experience talking here) it should be totally doable to work on it without cutting any wires or unwrapping any wire-wrap connections. Might have to clip some wire ties to get enough slack, but you always want to avoid fooling with the wire-wrap or clipping wires.
 
I was planning to order through mouser just to expedite things since they should have all in stock. I notice that CKk11 the non polar cap listed in parts list shows to be
47µF 25 WV but the one I removed is a 16V 100µF??? I will order both just to be safe. Also, any other parts you recommend ordering at this juncture? Thanks again.

note: schematic shows it to be 16V 100uF so that is what I will be ordering.
 
Last edited:
If you have no spares at home, I'd order replacements for all the transistors in the protection circuit.

Qk1 - KSC945CYTA*
Qk2 - KSC2690AY
Qk3 - KSC1845FTA
Qk4 - KSA733CYTA*

*Note the 'C' suffix denotes these parts as having the center lead as the collector, probably just like the original parts. There's also a version with a center base lead, but since Kenwood usually aligns the solder holes in a neat, straight row, expecting a center collector part, best to use a replacement that also has a center collector lead. So, looking at these two parts (the A733C and the C945C), with the 'flat' facing you, left to right, it's emitter, collector, base.
 
No spares, I am just getting started in this although I worked on electronics for about 16 years for a living and still do however not to even the board level at this point.
I would like to know how you got the part numbers for those transistors so maybe I can look them up myself next time.

I placed the order with mouser, hope it shows up soon as I would really like to get this receiver back to my father in law all cleaned up and ready to go for fathers day. He purchased it new while stationed in Germany in 1975 and it has been broken for several years. Thanks again.

Bill
 
I would like to know how you got the part numbers for those transistors so maybe I can look them up myself next time.
1. They are available, unlike the originals (95%+ of all Japanese transistors used in the 70's are out of production and have been so for a few decades).

2.The requirements here are pretty simplistic, but in general, if the replacement transistor can handle the voltage and current it will be subjected to, and the pinout is not a barrier, then it'll work. Well, that and I've been staring at spec sheets for 35 years.
 
I replaced each electrolytic cap on that board and also replaced Q1. I also tested Q2, and it seems to test good.

I am hesitant to do too much work nith this soldering iron since it gets super hot and am afraid of lifting the solder runs.

I then powered up and I hear the relay click. I kill power and hook up speaker. I just used the radio with no antenna and can hear the stations, however even with volume turned completely down, I have a hum/buzz, some noise. It is there no matter what input I select. I plan look at some other stuff tomorrow but that is the update for now

Any thoughts Thank you.
 
I'm thinking of replacing main power filter caps.

I just noticed balance control doesn't seem to have any effect? I will tackle that late after resolvimg buzzing noise.
 
Power off, and pull the pre-out/power-in jumpers in the back. Still hum when you power it back up?

Looks like the whole premp runs off of a single +33V supply. But this 33V regulated supply gets its voltage from the large 12,000µf 63V filter cap. So, if you have hum, the big caps need replacing (and probably many others as well, especially those in the 33V regulator), or you have a broken ground wire or burnt ground trace somewhere.
 
Back
Top Bottom