• 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

Marantz 2216 recap

Usually if there is an issue in a pre it's isolated to a channel, why do you think it's in the pre? Did you test it on headphones yet? That's a good test.
 
Last edited:
Hi Hi, im back! It was not my intention to leave this story unfinished but my baby daughter was born two weeks ago which explains my lack of time...

Anyways, I tested it with headphones and I have exactly the same problem. What does that mean? Do we keep on looking at the pre amp or go to the main amp?

thanks a lot!
 
Hey congratulations man!!!

The fact it is in the headphones all but eliminates the main amp as the problem. How about those controls in the tone section are they good and clean? Any change when you adjust the bass/treble?

How far are you from NY, come on over have a beer and we'll throw the scope on it.
 
Thanks man! would love to drop by but I live across the pond in the Netherlands :P...

If it is not the main board is there then something else than the pre amp?

The tone board controls have been deoxited and I hear no change when I move them (other than more or less bass or treble as applicable).

As always many thanks!
 
If your source is going through the aux the preamp is the only section left to address. You've cleaned the tape monitor switches, and went through the tone section so by elimination. Do you have freeze spray? When the noise occurs give the transistors a quick shot and see if anything changes.
 
Hi again, sorry for the delay, same reasons as before: beautiful baby! I dont think it would make sense to spray the transistors as they are new (i replaced the old ones already)... see below the summary of how things went for brainstorming purposes.

Summary so far:

1) The distortion appeared after recap of the power supply.
2) Power supply has been thoroughly tested and ruled out as the problem (thnx to bktheking!)
3) The tone board had been messed around before I got there. Where I should have found 1uf caps (according to the service manual and according to photos of other tone boards ive seen) i've found 3,3uf caps. Dunno if this has any impact on anything.
4) The 100uf cap on the tone board was original and had failed (leaking from below) so I started replacing that one. The distortion was gone for like 30 secs only after blowing the new cap which I had placed backwards (ups!). (this might be a clue, I will come back to this)
5) I replaced the blown cap and placed it correctly: Distortion is back
6) I recapped the rest of the tone board and replaced all transistors on the board: no improvement.
7) I've just bought an old scope but have no idea on how to use it, Im studying a bit
8) I have this crazy idea while I was sleeping that maybe if I replace the 100uf cap with a slightly higher value still in the range of the allowed +50% as per the service manual I might solve it. Why I think this? Because:

a) the distortion affects both channels
b) that cap is the only part of the tone board that affects both channels all of the other components come in pairs and are mirrored (per channel).
c) when I placed that cap backwards, though only for a second, the distortion dissapeared.
d) we have concluded (as per the headphones test) that the main amp cannot be the source of distortion, so we are left with the tone board.
e) Maybe the capacitance of that cap is, after recap of the power supply, not enough to filter properly.

Maybe my whole logic is flawed, but I dont lose anything by trying. I will throw in a 150uf 50v cap and see how it goes. After that fails (hopefully it wont) I will seriously take on the amp with the scope.

Please feel free to give your opinion or thoughts! Thanks!

Cheers!
 
You can bump that cap up to 220uf, but since you put it in backwards you now have to check other things. It sounds like this problem is not surfacing unless full voltages are being applied to the circuit, (sounds good for a few seconds at power up and down) so pulling a component to test it may not show that it is a failed component or not. You can pull one leg of the resistors before HE01 and HE02 and check values, you can also check the voltages of the E,C,B of these transistors to make sure nothing else got taken out.

HE01 and HE02:

B=2.9V
C=30V
E=2.4V please check scematic on these

and also HE03-06.
 
Last edited:
What do you mean by "pulling a leg"? please note that I am a newbie... I very curious and eager one but still...

What about the fact that both channels are distorting? could two components at the same time have been blown?
 
Last edited:
varox84 said:
What do you mean by "pulling a leg"? please note that I am a newbie... I very curious and eager one but still...

What about the fact that both channels are distorting? could two components at the same time have been blown?
Click to expand...

To measure the resistance of a resister you need to unsolder one leg and pull it up from the board so you can measure it, they can not be measured in circuit. Or if you want you can remove to measure. You may want to check RE01, 02 03 and 04 as it looks like they could effect both channels. Checking the voltage at the base of HE01 or HE02 (scematic says 2.9V) could be off because of this. Sometimes when you put a cap in backwards it takes out other components and sometimes not.
 
If that all checks out ok, I would look to the power switch for arching noise etc. Then revisit tone controls slowly move each one listening for changes.
 
So far I checked the voltages of the transistors on the tone board and all but H05 and H06 checked out ok. (Remember these are brand new)

The values of the two faulty were as follow:
(Schematic values between brackets)

H05
E - 0,2 (0,2)
C - 0,6 (13,5!!)
B - 1,0 (0,9)

RE39 and CE13 go into the collector of H05.

H06
E - 0,3 (0,2)
C - 0,6 (13,5!!)
B - 1,0 (0,9)

RE40 and CE14 go into the collector of H06.

Should the next step be checking these resistors? the caps i can just replace (have no way of testing capacitance anyways)

I leave here the relevant schematic for ease of reference.

tone_board_2216.jpg


Thanks!
 
Last edited:
What is the voltage of pin J810 on the Power Supply? And JE09 on the tone board?
 
Last edited:
It is 32,9 on the power supply no problem there. will check j09 on the tone board later. Need to attend to the baby, :P sorry
 
and JE09 on the tone board?, also clean the crap out of and flush the hi filter switch and cycle it.
 
Cycling just meaning press it on and off repeatedly. Spray it, cycle it 10-20 times, spray again, cycle again 10-20 times. You can repeat a few times.
 
Check JE09 as Pat said, also check RE45 for value. What transistor did you replace those two 2SC1328 with? KSC1845?
 
yes, That board has new transistors: ksc1845 and FSB992, I will check voltage, check RE45, and cycle the hi filter in an hour or so and will let you know. Thanks!
 
You must log in or register to reply here.
Back
Top Bottom