Working over my RX5600, a level difference while playing tape turns in a nightmare
Working with BBX electronics is a real pain, when the fix is not as easy as replacing something like a chip amp.
Fault with more than one cause like level difference can locate everywhere.
Talking with another member, gave me an advice about capacitors. He was right. When I started looking inside most were bad like this one



Then I decided to change all of them ...

First I took two photos of the main board.





Then I printed them, as big as I could see each capacitor.

Then I write the value in each one on the paper, to take a safe copy of the design before I started to unsolder all of them

With al capacitor located I make the list of the values I needed counting they from the photos. I checked 2 times with the mainboard, looking for some forgot capacitor.

As a rule, If a have many caps with the same value and different voltage ratings (4.7uF at 6.3V, 10V and 16V) I bought only the large voltage to avoid the mess. Using a 16V in the place of a 6.3V works well, but it's not as cheaper as the first.

With all capacitor at home, I started the work.

I unsolder all capacitor of some value, and the put the new ones in it's place. I used the photo again, so I couldn't get lost.
Before putting each, check that the value is right (some dealers mix values)

I turn one terminal of each to hold they while put the mainboard with the botton side looking me.



Checking 2 times polarity is a good option ... This board from Panasonic has marked the minus terminal of each.
Then, I solder all the capacitor of some value.

After soldering a value I performed a polarity check again.

I did the same with each value until I finish.

Then you need to inspect the board. Soldering, unsoldering and working can shield some shortcircuits. Looking carefully avoid the risk a permanent damage.
I cleaned the board with isoprophiliyc alcohol and a toothbrush before inspection.

I inspected the board 2 times. I found little pieces of solder, that I droped while I was unsoldering.

When you fell tired STOP, and continue later.
I sttoped onece. But twice looked more compresive. Mistakes at long running tasks are easy, and in this case SERIOUS. But as long as I have the photos I can inspect the board if it doesnt work and don't get damaged.

While changing the main capacitor (the big one) it would be great to increase it, to get some more short term power.

The RX5600 took a 3300uF. I put a 4700 uf in it's place. The value of it isn't critical ... so a little big is better. But Much more bigger shields a greater stress to the transformer during the startup. (I wouldn't use a 10000uf).

Good luck !!!!!

Good information with good pix. One comment: when getting replacement capacitors, try to use 105°C, low ESR capacitors, these perform much better than the run-of-the-mill 85°C ones and usually only cost a little more. Other advantages are that they will take more abuse and last longer.

A nice tutorial. Thanks!!

Well the real question is did it fix you problem when you were done?

The only problem with changing to higher voltages is the cap size increases, but your right, no effect on circuit operation if you increase the voltage values.

Photos are a smart, writing down each refdes (C1, C2 etc) its value and voltage is the best way to go.

Good job.

Very nice work and a great tutorial. I have some boxes I'm planning on performing this on so this is a great help. Thanks!

Excellent work Success, thanks for the info.

Outstanding tutorial. Information worth having for sure.

Thank people !!!

Kitt, on that National performance doesn't improve with this work. Hovewer the BBX needed it because about 40% of the caps was lackaged or corroed. Worst is that this National like other Panasonic boxes (I remeber the RX-C45) has many resistors and jumper tracks on the Top layer of the PCB that actually is a single layer to be honest. Some corrosion was quite near of the resistors and tracks . Permanent damage was near. In another cases corrosion went to the pads. The smell while unsoldering was terrible

In another National (my mono 1450) fixed several problems after recaping it.

Yaeh the only problem with higher voltage is the size, but as modern caps are more little than the old ones, even chosing a higher voltage cap is smaller than the original ... No problem, and the list of components is shorter ... I'm not National Panasonic crazy to save 0.00000001 cent using a 10V instead of 16V cap

Thanks leestereo for the tip. I put the first I found . But some little electrolitics (0.1uF and 0.22) were hard to find, believe me !.

hi success thanks for the info it always works out after i did my sanyo 920 the diffence was tremendous
my next one will be the 9994 that is in need to, good work

SUCCESS Thanks for the tutorial.. it gave me many ideas as to tackle this very same project in the near future. Thanks again...

any fix that keeps em going longer is A1 in my book....great job!