It's time for another "take apart and fix leaky caps report". This time it's the AIWA HS-F505. It is a unique model as it is a recording walkman that features a digital counter/clock and an external speaker as well as DSL and bi-azimuth HX head. I have a just a few caps left to replace them on this model, so why not. Big Digi-Key order coming up, and more re-capping to follow when it lands.

So this is the back story. I bought this recently from a chap from Germany and it arrived today (why do all the interesting AIWA models come from Germany?) In the words of the seller "leider doch ein fehler ein immer durchlaufendes neben gerÄusch und das laut und sobald dolby eingestellt werden mag ist es noch lauter" which roughly translates as - it sounds bloody awful and even worse when you switch on Dolby.

Anyway, upon opening it's the usual story. sticky corrosive electrolyte everywhere. As you can see below the ground point next to the internal battery terminals has nicely crusted up to a white colour. The mic socket is also covered in a nice dark brown gloop.

This is what it looks like underneath.

Testing the capacitors it is very interesting to reveal that I got >99 Ohms on the ESR meter (ie off the scale) for all the 4V surface mount capacitors. It is a good bet these are all dead. The through hole capacitors all read values that were < 2 Ohms, and for 2-4V caps this is a reasonable ball park to expect.

The surface mount caps are removed and tested again, the ESR readings are still over 99 Ohms. Testing with a regular capacitance meter the 47uF and 100uF caps read zero Farads. The 220uF caps manage a measly 3-4uF. I also remove two of the through hole capacitors to allow better access to the surface mount capacitors. Whilst I have them off board I also test them too. ESR is still < 2 Ohms as before. These read ~20% of their rated capacitance values, in other words within spec and still good. I will keep these to put back later.

The board is cleaned with a thin paste of bicarbonate of soda to neutralise the sticky acid ooze and then rinsed off. I preheat the oven to 100°C and then turn it off. I then pat down and dry off any excess water from the PC board before putting it into the oven to dry off.

Whilst the board is drying it is time to tin off the new caps. Here they are bottom right to the crappy dead ones on the top left.

This is what the bottom of the leaky caps look like - nice.

Now it's time to get the board out and re-tin the contacts for the new caps.

Then fit the new surface mount capacitors and reinstate the good through hole capacitors.

The external speaker has two 220uF 4V surface mount capacitors. These too were of the same brand as the leaky ones in the main unit. They've nicely corroded the tracks underneath the conformal.

These are removed and the board is cleaned. There isn't much I can do about the corrosion under the conformal. It will have be left as is until perhaps another time to remedy.

The contact points are retinned, along with a few components where the points have oxidised badly. The new capacitors are fitted. Along side are the old caps. These tested exactly the same as the 220uF from the main unit.

So the listen test. In a nutshell - it all works! No nasty noise, no louder nasty noise when Dolby is engaged. As to be expected from this early 90s AIWA DSL bass when engaged is stupidly loud and deep in this unit. Volume is very loud on it too. Even the tinny little external speaker manages to chuck out a decent volume for it's small size. It is quite a bright sounding walkman, but not as bright sounding as the PX505.

When I recapped one of my Aiwas the DSL is stupidly loud and overpowering on it too.

I really like your Re-capping guides.

I finally got around to test the board on my JX707 (but with caps too big to fit, so it's only a temp for testing until I can find smaller caps). The result is great (could only test radio as the caps are too big) and the talking voice is amusing. I also have a JX70 (707 with TV radio) but could only get the left channel to work. (I still don't have the battery pack though, which really sucks.)

I have a question to ask. On your JX-707 recap you stated some parts from Digi-Key. I've checked the height values and they all seem to be just slightly too tall for the 707. How did you get yours to fit in eventually? Does the board have a bulge in the end?

Hi Bub,

Thanks for the positive comments on this post. I am never sure whether I should continue doing these posts as so few people comment on them at all. It does take quite a while to complete the whole process, having to stop at each point and then take photos and make notes when I could just get on with the task of just removing the old caps and putting in the new. So thank you again for your words of encouragement.

Regarding replacing caps for the JX70 series, yes it is a real tight squeeze in there. The part numbers I have quoted for the surface mount caps will fit. However owing to the lack of space, you must ensure that when soldering, the surface mounts are flush with the PC board. The tallest components are the two Panasonic through hole 220uF 4V, with persuasion these will fit into their allocated space too. Badly installed and you won't be able to apply solder to the playback solenoid. If installed correctly, there is a very slight bulge from the through hole caps. I quite like the Japanese woman talking English.

Have you ordered any parts from Digi-Key yet? If not, my advice is to bulk up a big order so as to take only one big hit from the couriers over-charging.

I sometimes wonder if headphone technology being what it was in the 80s and 90s that electronics manufacturers had to really pump the bass on their walkman so that it was noticeable. I currently listen using a pair of 21st century MEE M6 IEMs. These are slightly bass heavy, but I have found this to be the case for all the main manufacturers. It is not so bad where you have a middle position on the bass enhance. In fact I find it is quite listenable, but for models that are all or nothing it can be very hard going to listen to them.

I really appreciate your threads and I know there are others out there who do too.  I have a few HS-PX/JX Aiwas like yours that needs this attention.  I will be relying on your guides for the work.

This a very informative thread plop, and the time and effort you put into threads like this are very much appreciated and IMHO feature worthy. 

Thank you everyone for your words of encouragement. I have a stack of non-working AIWAs currently piled up and now after repairing the F505 am fresh out of capacitors to repair them. I have a couple more AIWAs to come (including a PX10) and need to assess their status before I can order make a big Digi-Key order.

When that order arrives and I have some spare time I will put together more walk throughs. I have the PX505 to finish off and also a PX303 and PL50 to start on. I am keen to see how they all perform once repaired.

How much did the couriers overcharge you? Here in Singapore the Digi-Key Delivery is S$30. I too may plan to order parts in excess (especially 220uf caps that can fit in small spaces). Most through hole caps I can get locally from stores, although size is sometimes an issue.

If you order more than 50GBP to the UK, then Digi-Key don't actually charge you for deliveries to the UK. The charges arise from their courier UPS. They add on a handling charge (fair enough, need to pay someone to process the paperwork), import duty on the items (ok, kind of expect that), and this is the part that really grinds my gears - import duty for the delivery fee for the delivery fee that you didn't pay for - remember that was "free" (wtf?).

So, if I were to order less than 50GBP, I'd get stung for the 12GBP delivery charge, plus the UPS courier charges mentioned earlier on top! This is why whenever I order stuff from Digi-key I need to bulk up on the order to take it beyond the 50GBP mark, to at least save on the 12GBP.

I notice when I go through the Singapore portal you also get a free delivery offer, but in your case you need to spend 135SGD. 

If members of S2G were to collectively order from Digi-Key we could at least lessen the amount charged between us.

We do have electrical component suppliers based here in the UK such as RS Components and Farnell, but unfortunately they do not have as comprehensive a range as Digi-Key for parts in the values required for AIWA, so I have to no choice but to use Digi-Key for now.

In searching for alternatives, Farnell singapore (element14) offers free shipping. I've tried to match up the size vs the caps you mentioned in your JX707 thread:

http://sg.element14.com/jsp/se...tail.jsp?sku=1899658

220 uf 4v Nichicon.

http://sg.element14.com/jsp/se...tail.jsp?sku=1698687

220uf 6.3v Chemicon. (slightly shorter)

http://sg.element14.com/jsp/se...tail.jsp?sku=1698403

100uf Chemicon.

http://sg.element14.com/jsp/se...tail.jsp?sku=1698409

47uf Chemicon.

Could you run me a check and see if these caps are suitable for a JX707?

You should be fine with 5.4 mm high capacitors for the JX707. It seems that the Panasonic through hole capacitor although specified 5.0 mm is definitely marginally taller.

I haven't bought any Nichicon or Chemicon brand capacitors so cannot say how close they are to their rated physical specifications, but IMHO if the 6.3V 220uF are cheaper seeing as they are slightly shorter, then get a few of those. Over specifying the voltage won't hurt. Same for the 47uF 6.3V.

The 100uF 6.3V Chemicon are too big diameter size, and therefore will not be possible to fit those. You should be alright with the 47uF and 220uF sizes. The 100uF needs to have a size of 5.00 mm dia X 5.4 mm or less to fit.

Interestingly I just had a look again at the picture of the Chemicon cap on the spec sheet, and it looks like they were Chemicons that were pulled from the F505.

Sorry I just double checked the 100uF sizes.

Actually the Chemicon EMVK6R3ADA101MF55G is too big at 6.3 x 5.2mm, but the Chemicon EMVA6R3ADA101ME55G at 5.0 x 5.2 mm should be alright.

Good to hear. The E55s should be correct then.

I'll most probably try to get both models of the 220uf caps. Sadly element 14 does not seem to have 220uf through holes that will fit. Luckily, I already do have a couple that will. Either that or try to fit an SMD's legs through the holes by trimming the width as I have tried on other machines.

I appreciate your threads also. Although I'm not a big walkman fanatic, I certainly admire the time and effort you put into restoring them. Definitely well above my capabilities.

I thought I was the only one that bother to fix these, at component level very glad to see others fix them, instead of throwing them into the landfill.

Hello retrodos and welcome to the forum!

Please do share your experiences here regarding the repair of walkman, so that we may all learn from each other. How many have you repaired and what problems have you encountered?

Repaired over 200 plus of various models, mostly AIWA with bad caps and Sony's with nylon plastic gears that shrink and crack and also have bad caps, seen some so corroded, due to the electrolytic leaking everywhere, that the capacitors actually fall off and traces are eated up, even after neutralise the acid's, as damage was done, have to jump or repair the traces. Will do video, once I start working on the next batch, right now working on some amplifier's and tv's