Marantz 2275 Recap & more

Push in the "muting" switch.
That wire feeds a multitude of boards and switches.
Like Kyle says I'll bet it got pinched somewhere.
Maybe pinched under the PE01 board shield below the pushbutton switches board.

Bob
 
Here's a totally stock power supply board from my 2275 so you can check your work.

You tried every board fed by the 13V supply, one at a time? I would have thought a board pulling the power supply down, but not if each and every one pulled it down on it's own. I'm kinda throwing darts here, but are all the grounds good? No wires pinched or nicked?
Thank you Kyle and Bob.
Yes, I did try one at a time, each gave me a funky reading. When all were disconnected, J806 gave me the proper voltage.
As suggested, I’ll look for pinched cables and test ground as well. It’s strange cause all other inputs, including Phono, work perfectly. Stay tuned.
 
Did some testing today and did not make progress.
Started with testing resistance between the 13.4v wire and ground. The fluke did not budge. Like I didn’t even connect the probes. So I set the fluke to VDC and turned my unit on. 13.4v what the hell?

I tested all other 13.4v wires separately, 3 gave me more than 1.5ohm but the one going to the FM mute button gave me 0.458ohm in the off position and 0ohm in the on position. I looked at the wires and they looked fine, I tried the wiggle the board....nothing changed. Looking for more ideas :dunno:
 
Disconnect the feed off of J806 and put your ma meter on J806 and on the wire to see how much current is flowing .

Bob
 
Disconnect the feed off of J806 and put your ma meter on J806 and on the wire to see how much current is flowing .

Bob
Thanks Bob! Let me see if I got it right.
1. Disconnect the feed off of J806 - OK
2. Set my fluke to ma and put the red lead on J806 put the black on which wire? The one I disconnected from J806?
3. Do I test it while the 2275 is on or off? I assume on?

Thank you
 
Yes power on
You're just putting your dvm in series with the wire you pulled off of J806 to see how much current it's pulling which should tell you one of two things:
1) very little current which could indicate the P800 14vdc supply is suspect
2) relatively high current which probably means you have a shorted wire somewhere since you have already disconnected every board simultaneously.

I'm still betting on a short somewhere.

I would go to the small terminal board under the chassis that's just behind the preamp board but in front of the P200 board and separate all 5 or 6 wires there that feed out to the rotary switched ,pushbutton switches and boards .
You should be able to isolate which of the wires is dragging down your voltage.

Bob
 
Yes power on
You're just putting your dvm in series with the wire you pulled off of J806 to see how much current it's pulling which should tell you one of two things:
1) very little current which could indicate the P800 14vdc supply is suspect
2) relatively high current which probably means you have a shorted wire somewhere since you have already disconnected every board simultaneously.

I'm still betting on a short somewhere.

I would go to the small terminal board under the chassis that's just behind the preamp board but in front of the P200 board and separate all 5 or 6 wires there that feed out to the rotary switched ,pushbutton switches and boards .
You should be able to isolate which of the wires is dragging down your voltage.

Bob
Thanks! I'll do that tomorrow.
About the small terminal board, do you mean H005?

Screen Shot 2018-04-10 at 10.07.49 PM.png
 
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Nope, that's the power rectifier to feed the power amps. I think it's the terminal strip just to the left of that and just a tad lower. The bunch of wires are usually orange in Marantz receivers but may be red in a 2275. I haven't done one in quite awhile.
 
Nope, that's the power rectifier to feed the power amps. I think it's the terminal strip just to the left of that and just a tad lower. The bunch of wires are usually orange in Marantz receivers but may be red in a 2275. I haven't done one in quite awhile.
Thanks @rBuckner

OK, so it's the part I highlighted in RED.
Already been there (the picture is before I disconnected all cables)
I started with disconnecting the cable coming from J806 (13.4V on the power supply) I disconnected it where the red square is in the picture. Testing it, gave me 13.66V which makes me believe that all is good on P800.
So I disconnected the rest of the cables inside the red square, they all feed the Tuner boards. I then connected each individually to the cable coming from J806 and tested each again. In each of them, the voltage dropped to 5v-6v. this is what stumped me. I'll proceed with the current testing as Bob suggested and update after.

Golan
 

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OK,
If you have done all that and with every wire disconnected from that terminal strip junction point AND then connecting each one individually ONE at a time to the feed wire from J806 you only get 5 vdc on J806 no matter which wire is connected then I would check the 13.6 volt power supply circuit with the wiring reconnected.
Check for 14vdc on the base of H804,32vdc on it's collector and 13.4vdc on it's emitter .
R809 (10 ohm) is usually used as Marantz circuit designer's "failsafe" protection on a lot of the boards.

Bob
 
Success!!
Yesterday, just before I left it alone, I decided to test H810 (Zener Diode) which I didn't replace.
It tested perfectly outside the board, so I put it back in and just left it as is, didn't even continue testing.
Today, I set everything up for Bob's suggestions. When I turned the receiver on, I saw the signal meter moving, I quickly connected the PE01 board, plugged my headphones and.....it's working :banana:. If anyone can offer an explanation, I'll be happy to listen, but at this point, who cares :music:

Prep for test.JPGTest.JPGSuccess.JPGAfter.JPG

Next, is new velum paper and LED's. I'll keep updating.
 
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I agree with Bob's suspicions that something was/is amiss on the power supply board with that zener being the #1 suspect. That or there's a cracked or crystallized solder joint that is temporarily connecting due to things being flexed and wiggled around. If it fails again at least you have knowledge of where to look!
 
Today was a good day. Managed to blow the 5A fuse after replacing the Filter Caps. Was ready to check the rectifier, but looked at the diagram first. I noticed that I used the word NEGATIVE on the old caps as my Negative mark, rather than reading that the black dot marks Negative :no:. All is good now.
Also replaced the lights with LEDs. What a pain to do the selector lights...

Going to grab lunch and then closing. I'll post final pictures when I'm done.

2275_PS_Caps.jpg LED.JPG Filter Front.JPG Filter Back.JPG
 
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