Most definitely NOT. This cap problem goes across the entire Aiwa range, even those that do not use Lead Acid Batteries. And to top it off, few Sony machines tend to suffer from cap problems.

While it is possible that the Lead acid batteries may contribute, so far I have yet to see a leaky one personally.

I'm guessing, either Aiwa purchased lower quality caps or perhaps used a technique that used too much heat in their wave or reflow soldering and affected the seals of the caps.

(BTW, if you still have that white crust on your 505, I'd clean it asap.)

One of my RX610 (628) machines had really bad yellow/white crusting as well.

You did a good job there, nice work!

That was some seriously bad corrosion. I can see why you did not bother to rescue the resistors. I had similar corrosion on a number of resistors on one of my RL50s, but after a good clean and a drenching in flux I was able to get them in a state where I was able to use them again. Your JX505 has all cleaned up very well. How does it play now?

Interesting proposal regarding fumes from lead acid battery. Any gas venting from the battery would have been hydrogen given off during charging, but I doubt this is the cause of the white crusting seen. This problem is not limited to lead acid battery models, as the PX410 is a non-lead acid battery model and I have one that has leaked electrolyte on the to do list for repair.

The white crusting is more likely salt deposition - a by-product of electrolysis occuring due to the nice pool of fluid leaked from the capacitors in close proximity to a strong steady voltage. Bear in mind that although the internal battery may not have been present, there is still ~2v at the positive terminal sourced from the AAA battery pack. I have seen the same white crusting on other AIWA models around the internal battery terminals in varying degrees. In the case of the JX505, it is coincidence that there is alot more extensive corrosion because of the higher concentration of capacitors in this part of the circuit board.

Refering back to the same RL50 I mentioned earlier, the worst corrosion it suffered incidentally was where electrolyte had leaked from caps nearer to the battery pack terminals. The damage was extensive, completely corroding through the positive power line, there was also heavy corrosion on the gold contacts and the gold pins of the AAA battery pack are now next to useless.

With regards to whether the battery compartment capacitors leak, I can testify that they also leak. I have a couple battery packs with leaky caps. I also had two 220uF caps leak in the speaker battery compartment on the F505 model. The pictures are in that thread for all to see.

I would concur with bub to say as much that in all likelihood AIWA either had been ordering badly made caps or there was some part of their manufacturing process that was affecting the lifespan of the rubber seals.

Yes there is a rechargeable battery in the door, plop has a thread on it.

After reading up on capacitors, I feel that the most likely explanation is that Aiwa may have used too much heat and affected the seals, as they seem to may have used more than one brand /series of caps. Maybe a cost cutting measure in the wave/reflow process?

Comparing some of my Japan made and Singapore made Aiwas from the 90s, the Singapore made ones tended to have caps that did not leak out. Unfortunately I do not have enough units to prove this statistic, so it is just a wild guess that the Singapore made ones may have a different manufacturing process.