Marantz 2220 No sound at all - P800?

ZeroG

Super Member
You know how it's said that no good deed goes unpunished? This is one of those stories.

I was updating a Marantz 2220 for a friend, new lamps, cleaned it up, the usual DeOxit treatment. It was working fine and I decided to take it a step further and recapped the P800 power board, as I had all the caps on hand already. Before I did that I checked the main filter and the two channel power caps. The main filter was reading 3230 uF on my ESR meter (should be rated at 4700), and I figured I would get to that after the power board.

After recapping the power board, there's no sound. Very slight power on thump. Unit powers up and all lamps work. Tuner meter moves when it reads a station. No sound out of the headphone jack.

I checked my work as I went, marked all the caps before removal, and they match the board polarity as shown by the old caps and also by the markings on the P800 board. Nothing appears to be backwards and no bang.

I reflowed the solder on the board, no diff.

Suggestions would be very helpful at this time. Anyone? TIA for reading this and and much obliged for any assistance.
 
Roger that. There is what I'm guessing is an unused pad under R803. Btw, this was not a virgin unit. I was not the first under the hood, FWIW,
IMG_3866.JPG
 

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I don't see anything obvious. I would check all the power wire going to the other board to make sure one didn't come loose.

Tony
 
Top of pic.3 img3871 looks like solder connection i would re-flow that one
Previously checked and reflowed that one. The solder joint is fine, it's the pic that makes it seem like there's not enough solder on the lead, but it's there.
 
If there is indeed 35V at J808 (measured 34V), does that mean that the board is functioning properly?

Also - I probed a bit with a home-made signal detector, tracing from the aux input (using phone) to the selector switch and the balance and volume pots. I found signal at the selector and at the volume and balance pots, but none on the P800 board or the P700 board.

Suggestions, please?
 
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If there is indeed 35V at J808 (measured 34V), does that mean that the board is functioning properly?

Also - I probed s bit with a home-made signal detector, tracing from the aux input (using phone) to the selector switch and the balance and volume pots. I found signal at the selector and at the volume and balance pots, but none on the P800 board.

Suggestions, please?
You should also have +12 volts at J809 and +14.6 volts at J810. Also check for any wires that may have broken while you were working in there.
 
You should also have +12 volts at J809 and +14.6 volts at J810. Also check for any wires that may have broken while you were working in there.
Thanks!
Got 12.3 at J809 and 14.5 at J810. All the new caps seem to be correctly installed. Would these voltages still be there if there was a bad diode, transistor or resistor?

I don't see any loose wires, but will do the magnifying glass thing again.

If all the voltages on the 800 board are there, could the issue be somewhere else, and if so, where should I look?
 
Thanks!
Got 12.3 at J809 and 14.5 at J810. All the new caps seem to be correctly installed. Would these voltages still be there if there was a bad diode, transistor or resistor?

I don't see any loose wires, but will do the magnifying glass thing again.

If all the voltages on the 800 board are there, could the issue be somewhere else, and if so, where should I look?
It must be elsewhere, as those and the +35 volts that Steven Tate pointed out are all the voltages that the P800 board puts out.

Do you get anything through the headphone jack? And try working the tape monitor button a few times.

Do you have an oscilloscope and signal generator? It's starting to look like it's time for some good old fashioned troubleshooting. :)
 
For what it is worth I would take my meter and check continuity between the cap solder points that were replaced to the trace that it feeds and see if it rings out at the next component. More than once I have had a problem with a channel dropping out with a solder joint that looks good but was not passing on the signal and found it doing this.

Worth a try anyway. Good luck.
 
When you checked the big caps, did you test them in circuit or did you remove them? Just looking for any chance of a polarity problem.
 
For what it is worth I would take my meter and check continuity between the cap solder points that were replaced to the trace that it feeds and see if it rings out at the next component. More than once I have had a problem with a channel dropping out with a solder joint that looks good but was not passing on the signal and found it doing this.

Worth a try anyway. Good luck.
Actually a good idea! I've already done that, though, and checked for continuity between the case and the neg side. It all seems in order. Must be something small I disturbed during the recap?
 
When you checked the big caps, did you test them in circuit or did you remove them? Just looking for any chance of a polarity problem.
Thanks also for this but I tested them in circuit with my ESR meter.
I would guess that a polarity issue with the main filter would have made itself known very quickly and very loudly.
 
Actually a good idea! I've already done that, though, and checked for continuity between the case and the neg side of all the caps. It all seems in order, BUT there seems to be an excess of ESR meter readings that say low impedance or leaky circuit. I've re-flowed them all and scrutinized them. Might be something small I disturbed during the recap?
 
It must be elsewhere, as those and the +35 volts that Steven Tate pointed out are all the voltages that the P800 board puts out.

Do you get anything through the headphone jack? And try working the tape monitor button a few times.

Do you have an oscilloscope and signal generator? It's starting to look like it's time for some good old fashioned troubleshooting. :)

Nothing through the headphone jack. (so does that mean the problem is in PS or Amp?)

The Tape Monitor switch occasionally feels a little click-ier /crunchier that it normally does. But I've worked it a few times and get nothing from either channel. IIRC all the signal goes thru it. I'll check it again.

I DO have a scope, Unfortunately I DON'T know how to use it. Is there a quick tutorial we could do? I'd like to know practical use, not theory if possible in this case.
 
Thanks! Here you go. I do have the probe, just not shown in the pics.
 

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