Marantz 2220 non-b shorted output transistor???? What replacements???

I would guess the driver TX as well. I had this same experience with a Parasound HCA 1206 after a re cap. I had to put it aside because it became too frustrating to continue working on. I hope you find the issue. I will bet you are homing in on it now.
 
Here are my thoughts at this point as I work through this. I am in the process now of checking the driver transistors out of circuit. Initial test in circuit revealed no shorts. I have suitable replacements for all but the silver saucer 2sc959 and 2sa606 but those are not really drivers as I understand it but current limiting devices if overload developed. Soooo I could shotgun h701, h703, h705, and h707. I could also re-install the old caps on that channel too, or both. So far I am not coming up with any bad parts unless I find something with the drivers when tested out of circuit and I'm afraid I'm gonna break those Stv-3's the more I keep screwing with this board in and out. What do you guys think?
 
If the new caps are ok, I would left him in place.
Regarding shotgun H701, 703, 705, 707... well, at least we are be sure that those are not the culprit, and must be something else right?
How about resistors? You can check them on board.
Let's see what someone with more experience says.
 
If the new caps are ok, I would left him in place.
Regarding shotgun H701, 703, 705, 707... well, at least we are be sure that those are not the culprit, and must be something else right?
How about resistors? You can check them on board.
Let's see what someone with more experience says.
Here is the thing with the caps. I am finding that my dmm won't check the larger values and it certainly does not put them up to working voltage, so I don't think that is going to be useful data. I was just considering putting the old ones back in that channel because I cannot confirm there may not be a defect in one of the new ones, but I can confirm that the circuit worked before all of this with the old ones. That's all. I am starting to get really frustrated with this thing. I was enjoying it so much. Never had a recap go sour like this.
 
but I can confirm that the circuit worked before all of this with the old ones. That's all
Fair enough, you can check if they are shorted with you DMM the Ω function.(just in case) but you probably know that.
I am starting to get really frustrated with this thing
Be patient, frustration sometimes is part of the game, take a break... you'll see that someone with nice experience will chime in.
 
Fair enough, you can check if they are shorted with you DMM the Ω function.(just in case) but you probably know that.

Be patient, frustration sometimes is part of the game, take a break... you'll see that someone with nice experience will chime in.
Thanks for that. I know it's all part of the game.
 
Update.....well I went ahead and completed checking all and I mean all of the components, lifted every resistor, checked every transistor and tested the new caps under 50uf as that is all my dmm will support, none were shorted, but I have seen capacitors short or go open only once they reach operating voltage. So I changed the back to the old caps on that channel and changed the transistors h701, 703, 705, 707 with suitable replacements and everything seems to be fine now. Was able to adjust idle current and played about a minute worth of music through it. Now the big question is should I put the new caps back in and see what happens? I hate to order a new batch pay shipped etc for no reason. I guess what I'm really asking is is there really any of those caps that could have taken down an output transistors or was this the bias diode coming off that more than likely caused the initial blow up. The more I think this through that's where I'm leaning. Probably replacing the transistors was the true fix since when an output shorts it can take out the supporting drivers with it, or at least weaken them. So maybe they test fine on a meter but the pn junction was going leaky or shorted under load. Who knows, just looking for other opinions and thoughts. Thanks all.
 
Probably replacing the transistors was the true fix since when an output shorts it can take out the supporting drivers with it,
That's what I think too... I've never had problems with new caps taken down outputs, just old caps and hums. And if they are not shorted.... I don't see problem.
 
I am just glad to see you have it back up. Things like this get me caching my tail and I have to put them aside till another time. Good show so far. No expert here not by a long shot but I wold put money on you being right about that diode creating this issue.
 
I think that's a safe bet. I put the new caps back in and all is still fine. Sounds good, bias sets right up and stable. Only issue have now which I'm going to start a new thread about is the dc balance/clipping adjustment. Thanks for everyone's suggestions.
 
I think that's a safe bet. I put the new caps back in and all is still fine. Sounds good, bias sets right up and stable. Only issue have now which I'm going to start a new thread about is the dc balance/clipping adjustment. Thanks for everyone's suggestions.
Glad you got her up and running again. they ain't making no more of them ! Saved another piece of vintage gear and Marantz at that. Great sounding equipment.
 
Back
Top Bottom