Marantz 2270 Low output on Phono and Aux, not on other sources

Put old diode back. It's orientated correctly. Channel (where resistor isn't blown) is still not working properly. More hum, little bursts of power but generally low output and little pops too. New voltages 701 B=1.12 C=1.82 E=0.68 702 B=0.81 C=2.25 E=0.35 703 B=1.82 C=7.8 but doesn't hold steady fluctuates down to 7.56 or so and back up E=1.28 704 B=0.35 C=8.4-9.25 fluctuates up and down E=0.07 705 B=0.22 C=18.8 E=0.85 706 B=0.0 C=34.4 slight fluctuations down and back up E=0.0
 
Thanks. I have all the old transistors I took out so can just swap that back as a temp fix but I don't have a 680K resistor to put in for R725. My question is that H706 is on the same channel with the blown resistor. Why are my voltages still off on the other side and it that side not working? I was hoping to get one side working before ordering the R725 and some other parts.
 
I put back all the original caps, diodes, and transistors on the side without the blown resistor. Still not working. I swapped the contralateral resistor into R725 spot and put in the old H706 transistor. That side is not working. Starting to think there are several components that are blown. I may be better off waiting until I can get a used board on Ebay and swap that in. I must have blown it when I blew the transistors on the PS board or could it have been because I substituted the wrong blob diode?
 
Looks like 2230 2245 and 4430 use same board. There is one on there now from a 2230 that had transistors, diodes, and ecaps replaced but for some reason it has WIMA caps in place of R712 and R713? What's with that? There is also one that is unrestored that I could just buy the parts on Mouser and stick them in.
 
@biggal76, do you want to troubleshoot your P700 board or are you going to buy one? If you are going to buy one, then it's of little value trying to troubleshoot your board. But, if you are serious about finding the problem with YOUR board, then we can proceed with further troubleshooting efforts.

Please list all of the components on the P700 board that you changed (including resistors, capacitors, transistors).
Also, please post a CLEAR photo of the top and bottom side of the P700 board.
To verify, ONLY the phono board does not work... all other inputs AM, FM, Tape, Aux work perfectly?
 
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I'm learning a lot and would have a sense of accomplishment if we can figure this out. I am just concerned that with my limited experience, we may not have success after 1 or 2 Mouser orders and a lot more time on my workbench. Guess I was getting pessimistic. I'm anxious to it fix it but realistically there is no rush, so if you are willing, I would like to try to do this. C713, R705, H709 obviously would effect both sides, but can failed components on one side of the board have any effect on the other side working properly? What would you check next? Also, I am just wondering why would that Ebay board have WIMA caps where resistors go?

Oh, just saw the second paragraph. I put all 6 transistors, all diodes and electrolytics back in the side of the board with odd numbers (H701, 703, 705, C703, H707, and C713) in hopes of getting one side working but it didn't. I then put the original diode back in H706(as voltages indicate that transistor is bad) and swapped R724 to R725 position (as R725 was open) in hopes of that side working-it didn't.
Would having the wrong diode in H709 cause other component failures? Would me slipping and shorting the PS board a while back (and blowing H805 and H806) cause damage on the phono board but no other board?
 
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OK, let's review the current state of the board.
  1. First, you can't properly troubleshoot the board when you keep changing components daily. You need to start with a configuration, then determine what is good and bad.
  2. Did the board ever work, or is this problem the result of updating components? If you replaced components since your last posted voltage readings, you need to do them all again. I would also remove H706 when making the measurements.
  3. Please post the photos of the front and back side of the board so I and others can verify any issues.
  4. Please list whatever test equipment you have.
biggal76 said:
Also, I am just wondering why would that Ebay board have WIMA caps where resistors go?
Click to expand...
I don't know which resistors you are referring to. When discussing a component, you should always refer to the part reference number.
 
dankik said:
OK, let's review the current state of the board.
  1. First, you can't properly troubleshoot the board when you keep changing components daily. You need to start with a configuration, then determine what is good and bad.
  2. Did the board ever work, or is this problem the result of updating components? If you replaced components since your last posted voltage readings, you need to do them all again. I would also remove H706 when making the measurements.
  3. Please post the photos of the front and back side of the board so I and others can verify any issues.
  4. Please list whatever test equipment you have.

I don't know which resistors you are referring to. When discussing a component, you should always refer to the part reference number.
Click to expand...
The board worked prior to me working on the receiver. I was just wondering if me shorting when measuring voltages on the PS board could have caused this and/or if having the wrong diode in H709 would have caused this issue. R712 and 713 spaces had the WIMA caps on the Ebay board. I only have a capacitor tester and multimeter. Will post pics and new voltages when I get some time.
 
I don't know what's going on with the Wima caps replacing resistors?

Are you sure that the P800 PS +35V output is good. It only feeds the P700 Phono board and the P300 FM MPX board. If there is noise on the +35V output, it could be affecting the Phono and FM MPX. Does your FM stereo work OK?

When you get a chance, remove H706 then remeasure the transistor voltages, J706 & both sides of R734.
 
Well, FM did work perfectly. I noticed a loss of reception this weekend. I thought it was weather related because I get poor reception in the basement where my bench is. I just hooked up an antenna and now get no reception. Will remeasure voltages as you instructed when I get home from work. Want me to check anything in particular on PS board? Voltages on H806? I found this post and could measure https://audiokarma.org/forums/index.php?threads/marantz-2270-main-power-board-dc-voltage.1010937/
 
Let's make sure that the voltages are correct first.
Please measure the voltage at J801 & J802 with the DMM (-) lead on J803.
Measure both the DC and AC voltage (use a lower scale on the AC since it will probably be small).

1745935846429.png
Measure the DCV at J753 and J761 with DMM (-) lead on J758.
1745935977531.png
 
dankik said:
Please measure the voltage at J801 & J802 with the DMM (-) lead on J803.
Measure both the DC and AC voltage (use a lower scale on the AC since it will probably be small).
801=.13.4vdc/0.3mvac 802=35vdc/0.3mvac

Measure the DCV at J753= 48.9 and J761=-48.9 with DMM (-) lead on J758.
Click to expand...
Not spot on but both are close. Are these voltages acceptable?
 
dankik said:
When you get a chance, remove H706 then remeasure the transistor voltages, J706 & both sides of R734.
Click to expand...
J706=35.2vdc What's weird is now both sides of R734 measure 35.2vdc. Resistor tests good. How can that be? I took out H706 and H705 for the measurements. Also, the PS voltage doesn't stay constant. Goes from 35.2 down to 32.2 and then back to 35.2 every couple of seconds.
 
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biggal76 said:
What's weird is now both sides of R734 measure 35.2vdc.
Click to expand...
When both sides of a resistor measure the same voltage, it means that there is no voltage drop across the resistor (no current being drawn through the resistor).
biggal76 said:
Also, the PS voltage doesn't stay constant. Goes from 35.2 down to 32.2 and then back to 35.2 every couple of seconds.
Click to expand...
That's not good, it should be a steady voltage.
Try and replace C713, 100uF/50V cap. That is responsible for keeping the 35V supply voltage at a constant voltage value. Also, make sure that it is installed with the correct polarity... (-) lead connected to J702.
 
I replaced the cap. New cap measured steady 97mf. Old cap jumping around between 110 and 120mf. Hooked up my leads to test voltage to J706. When I turned on the receiver, R804 blew-glowed like an orange light bulb. I triple checked no boards were shorted and haven't changed anything else since my last voltage checks so have no idea why that would happen or if other PS components are damaged now. I have some 10 ohm resistors but the original is rated 1/2watt and I'm not sure what mine are rated. Probably less. They were cheap and are small. No point changing it until we know why it blew anyway.
 
Do you have it on a Dim Bulb Tester (DBT). It will help from damaging other components. If you don't have one, then you should construct one before doing any further testing. There are instructions, many places on the internet.
biggal76 said:
R804 blew-glowed like an orange light bulb.
Click to expand...
R804 - This is a good clue as to which voltage is causing a problem.
(This is why it is important to keep your prior history of your repairs. I seem to recall that you shorted out something in the power supply before?)
Here is a link to your old thread:
https://audiokarma.org/forums/index.php?threads/marantz-2270-restoration-issues.1083102/
1746063422886.png

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biggal76 said:
Yes, I have one. Where do I start to get this PS working. What would have blown that resistor?
Click to expand...
Most likely something shorting, or near shorting, the +35V output to ground. That resistor is there to drop some voltage and therefore heat normally from the series pass transistor H805 so it runs less hot. That transistor could've sustained damage so I'd be checking it too. You may want to temporarily wire in a fuse to the +35 output of about a half amp until your unit is working reliably.
 
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