Marantz 2240 almost successful restoration

[stefhelm]

Hi,
I've been absorbing lots of advice but haven't posted anything here before. I just finished restoring a Marantz 2240 with the Marblehead Audio "ultimate" kit found on eBay. It actually seems to have gone mostly ok. For me, it's a large soldering task. Learning as I go.

I think I have an issue on the phono board but I'm not sure how to pin it down. I have a white noise/static that is fairly loud. All other inputs as well and AM/FM sound great. There is nothing connected to the phono inputs. The static is equal on left and right channel.

Voltage in on j406 and j408 is a stable 36v. Electrolytic capacitors are all swapped. 7 total. All 6 transistors swapped. I checked manual diagrams to confirm they are in the right way (transistors and caps). Most advice suggests it would likely not be equal on both sides of it were a failure on one side or the other of the board. Nevertheless, tried to check what I know, and check solders. The h409 component is mentioned a few times. I swapped it with a pair of diodes in series but it made no difference. The kit did not come with c401 and c402 so in ordered those caps and swapped. Again, no difference. The selector knob is mentioned in threads so I clear that with deoxit but heard no difference.

I do think it is just the phono board. I know it is amplified a bit more that other inputs, but I can crank other inputs all the way with very little noise.

Here is the sound:

Here is the phono board in case someone can eyeball the issue and call me out as an idiot.



It seems like a very common noise, and I have overlooked something basic here.

I did damage a tracer on one channel but I repaired that. I don't think I damaged much else. Clearly I did something!

Any advice is much appreciated. I was feeling pretty good about getting it all done and this last issue is really bothering me.

Thanks,
-Stefan

 

[rBuckner]

Well, one thing I see is what looks like 1uF caps at C405 and C406 that should be 40pF. The white rectangular ones that say 1J63 on top.

 

[stefhelm]

Hmm, I think you are correct. My parts list from my kit has nothing for C405 and C405 and I for sure put those 1J63 is. I only had parts for 401,2,3,4 and 413.
I may have to shove the old ones back and order something.

I will start there! Thanks so much for taking a look.

 

[stefhelm]

Thanks rBuckner!
Obvious in hindsight, I suppose. It was the first board I tackled (ever) and I misread the diagram.
I even remember wondering why I was removing C405 when it was not an electrolytic can, but figured I read things correctly so I carried on.

I think this is more like it:


Of note - there was nothing wrong with the Marblehead kit. It was excellent. This was just user misinterpretation.

Thanks again!
-Stefan

 

[rBuckner]

Sooooo..... is it now working?

 

[stefhelm]

Yes! All functions work as they should now.