Marantz model 2216b

[henrysin44]

Out of nowhere my Marantz starts making these horribly loud crackles and pops from the left speaker with volume set to zero. I unplugged the left speaker and the noise went away so its not internal noise. I tried the right speaker on left and heard the terrible noise again. I also tried speaker system 1 & 2 both had same results on left. BTW change in noise didn't change when i adjusted any knobs.

[rhomanski]

Re: Marantz model 2216b

Sounds like one of your small signal transistors is out. Check around the output stage for a 2sa726 or maybe a 725, possibly a 1312 or 1313. Those are the most likely to fail like that but other types can too.

Another possibility is a dirty switch but usually they give more warning. They start a little noisy and slowly get worse.

[henrysin44]

Re: Marantz model 2216b

Sounds like one of your small signal transistors is out. Check around the output stage for a 2sa726 or maybe a 725, possibly a 1312 or 1313. Those are the most likely to fail like that but other types can too.

Another possibility is a dirty switch but usually they give more warning. They start a little noisy and slowly get worse.

I don't want to sound stupid but how to i go about checking transistors.

[budm]

Re: Marantz model 2216b

What kind of electronics tools do you have?
You can download the service manual from here:
http://www.hifiengine.com/library/marantz/2216.shtml
I agree, more likely to have bad transistor.
Unit this old you should also check for any crack/rings around solder joints and remove any brown/dark brown glue from the boards and components.
Those 4.7uf caps are known for leakage (not blocking DC any more). The volume controls feed the 3-stage tone preamp section, so that section needs to be checked also.

[shortchange]

Re: Marantz model 2216b

Can you use headphones to stop the speakers from damage.
And please be careful of hurting your ears.

Does the "HI-FILTER" switch change the high frequency pitch crackles and pops?
this switch is after all the controls and before the input of the power amp.

[henrysin44]

Re: Marantz model 2216b

Can you use headphones to stop the speakers from damage.
And please be careful of hurting your ears.

Does the "HI-FILTER" switch change the high frequency pitch crackles and pops?
this switch is after all the controls and before the input of the power amp.

Tomorrow ill find my adapter and see if anything comes out of phones and ill check the hi-filter

[henrysin44]

Re: Marantz model 2216b

http://www.henrysinclair.com/marantz2216b.png

Is this the output stage? Sorry to sound stupid but I've only just gotten into stereo repair, only really done TVs and computers.

[budm]

Re: Marantz model 2216b

P700 is the power amplifiers/power supply board. You will still hear the noise through the headphone because the headphone jacks are is connected to the power amplifier outputs.

[henrysin44]

Re: Marantz model 2216b

Ok so I took output transistors from my pioneer 40wat receiver and all 4 put in blew up, is their a specific set of transistors i should buy.

[budm]

Re: Marantz model 2216b

Did you download the service manual? What do mean by "Ok so I took output transistors from my pioneer 40watt receiver and all 4 put in blew up"? You just put them in the Marantz? Matching the spec of the transistors, etc?

[henrysin44]

Re: Marantz model 2216b

not exactly, i kinda winged it hopping it would work, ill look at the pdf and order the most compatible.

[shortchange]

Re: Marantz model 2216b

Did you try it with headphones before taking out your old output transistors?

Before getting new transistors:

Disconnect all speakers.
The receiver's driver transistors can drive the headphone circuit but not speakers.
In fact you will be able to hear any faults like a hum, distortion and/or a channel out using just headphones plug into the headphone jack in the front of the receiver and NO output transistors.


Remove ALL the output transistors and do NOT instal any output transistors at all.
As you take them out please take note and let us know of the numbers on the transistors. The two in the center should be B507 (2SB507) in the middle of the output stage and D313 (2SD313) on the corners.
Are the insulators look ok? (O49F)

If you have an ohmmeter from the metal chassis you should not see much of any resistance to any of the center lead of the output transistors. No dead shorts!

Before you plug into the wall make sure:
All speakers are disconnected and
All output transistors are removed.

You will probably still hear your popping noise.
Now does the "HI-FILTER" change the sound?

By the way if you still hear the noise your original output transistors are good but please do NOT install them yet and do not use speakers.

[henrysin44]

Re: Marantz model 2216b

I found out that the bad transistor is a small transistor in between 4 output transistors, and hi-filter seems to make things have more bass

[shortchange]

Re: Marantz model 2216b

how do you know the transistor is bad?
Q705 or Q706 2SC945 (C945 with a letter Q) is the bad transistor?
Have you removed the pioneer transistors?
Are you using headphones?

And hi-filter seems to make things have more bass.
What are "things"? Do you mean the popping noise is "things"?

As rhomanski said around the output stage and as budm said too
those 4.7uf caps are known for leakage and that can cause your noise.

[shortchange]

Re: Marantz model 2216b

Resistor RE35 or RE36 2.2 M OHM ±5% 0.25 watt may have caused the popping noise if you want to wing it.




http://www.ebay.com/bhp/marantz-2216b

[henrysin44]

Re: Marantz model 2216b

GREAT! I busy with school work so i didn't spend much time explaining what i figured out, I ordered a KSC945CGTA from fairchild which is a exact copy of the small transistor that had a burnt mark on it. And I tested the main output transistors and they work. I will get that board you supplied in the link as my board has really bad heat damage causing the traces to just crumble off

[rhomanski]

Re: Marantz model 2216b

Be careful with the leads. I believe Fairchild has swapped the collector and base on their version from the original. The one you ordered is EBC, the old 2SC945 was BCE. I have a cheap meter with an HFe function, it works pretty good for figuring out the leads on transistors. I got it from MCM electronics for about $15. , .

[henrysin44]

Re: Marantz model 2216b

Be careful with the leads. I believe Fairchild has swapped the collector and base on their version from the original. The one you ordered is EBC, the old 2SC945 was BCE. I have a cheap meter with an HFe function, it works pretty good for figuring out the leads on transistors. I got it from MCM electronics for about $15. , .

Just my luck, swapped pins!