I'd like to get a set of replacement caps for my 303 , i had to change 2 of them in the past because the sound got weak ,fortunately the 2 were near the battery housing , the ones i had found were to tall to fit so i put them horizontally in the battery empty space , i used some 6,3 volts instead of 2 or 4volts(don't remember) but with no incidence to the sound. Now i'd like to replace them with small enough ones since it seems we can find some equivalent on digi-key ! As you can see too , there is some leakage for one , although it still works fine , i should better replace it. My problem is easyly locating the right caps , it seems digi-key is a good shop for that , the problem is you have too search into thousands of caps and you're not even sure of what you order... May be someone has already some references for the caps i should buy please ? Any similitude with another Aiwa walkman ? Look a my photos , thanks for your help !

I also had took measurement of the caps if necessary.

Here they are:

Through holes ones(some through holes - some surface mounted but all "through holes" type):

2x 220 uF 2 v  diam 5 mm  H 6 mm

3x 220 uF 4 v  diam 6 mm H 6 mm

1x 47 uF 4 v  diam 4,5 mm H 6 mm

1x 47 uF 2 v diam 3 mm H 6 mm

metallic(cms) surface mounted:

2x 47 uF 4 v  diam 4 mm  H 6 mm

1x 100 uF 4 v diam 5 mm H 6 mm

This is now all the 10 identified caps for the JX-303.

Cosmos,

For a reference point, please have a look at this thread

index.php?board_oid=193392314111653483&content_oid=217178235650847317

BTW that is some really nasty corrosion on the legs of that horizontal cap.

check out plop's capacitor  thread- yours is similar to a JX505 I believe.

There seems to be alot of leakage on your board- you will need to clean it and replace all the caps. I use sodium bicarbonate (also plop's suggestion).

I also use mild dishwashing detergent. (The stuff works wonders on my boards- especially those with bad leakage.) I then dry them with a hairdryer, resolder, and stuff it in a box of silica gel. I had several "cranky" boards that worked perfectly after this, and so far I'm loving the results.

Thank you ! Had already read the a bit the capacitor listing thread , are they all the same size than originals because i haven't read any measurement indication ? Or are they so recent they would fit even in the latest walkman as well as in an earl'y 90's ?

Bub , have i well understood your meaning ? Cleaning an old cap is that it ? That's was i was thinking about , then "closing" it with some "glue" to avoid future leakage ? No risk of explosion or heat ? 

@Bub:When you said the 303 was similar to the 505 i can only disagree ,i once bought a 505 and it sounded...horrible ! Absolutely flat with no bass ,i even thought this was Aiwa's end in term of quality sound... Going smaller and smaller , i thought this meant going worst , later i bought a jx-849 and sound was way better. The 505 is nothing compared to a 303 !

No, I am referring to cleaning the PCB all the old caps should be replaced with new ones.

The caps listed should fit your unit as they are similar. And yes, the cap listing should fit many walkmans as these are some of the smallest replacement caps found so far.

As for the JX505 sounding worse than your 303, I am willing to bet your 505 had leaky caps or other issues as well.

Surely not leaky caps ! Impossible !!! Because i bought it new in the box at its release ! Did you ever listened to a jx303 ?

The following are close to if not the same size as the original

Radial

47uF 4V

SMD

47uf 4V

100uf 4V

The 220uF 4v through hole radial is slightly taller than the specifications listed, but for the JX303 this will not be an issue, as I have used this same capacitor in a JX505 and F505 without any height issues. I am not sure how much space there is between the 220uF 2V, but if there is enough space then these could be replaced with 220uF 4V. I believe these are the DC blocking capacitors on this model, so would hesitate to replace with ultra low ESR audio grade tantalum capacitors (very expensive). Or you could order the 220uF 2.5V SMD from Digi-Key and trim the legs down to fit as alternative option to using tantalum.

I notice there is a horizontal thin radial that you have not mentioned in your photo.

@Cosmos.

I have a fully restored (replaced all caps) JX505 and I can assure you that without DSL there is adequate bass. With DSL enabled there is truckloads of bass.

The JX505 was the ultimate in terms of features, but it was not the ultimate in terms of sound quality. For that accolade I would give to the PX505.

May be it had troubles ? New but ... this is well the one which does "tee-tee-tee-tee..." when you tune or press a button ? I'm sure it was the 505 , i gave it back to the shop.

Yes the very small horizontal cap is not mentionned because it's unreadable ! But no leaking there. So if those are the smallest caps we can have i'll buy with confidence ! I will read carefully all this , i'm not willing to use tantalum ones.

I think most of the 505 line went beep when you pressed a button of sorts.

Yes i think this was Aiwa latest innovation at the time as BBE sound....

BBE was licensed to AIWA from the early 90s. It was applied to good effect on the 505 line. Later models, well not so good. Strange how it is now coming back into vogue again with MP3 players such as those by Cowon.

OK now , let's go for a new youth my JX303 !

Here are some actual photos , notice the caps change(only 2) and how i managed to fit them inside , hope the future ones will fit better...

So what we have here:

2x 47 uF 4v diam 4 mm surface

1x 100 uF 4v diam 5 mm surface

a very small horizontal... unreadable but seems fine. surface

3x 220 uF 4v diam 6 mm (big horizontal is one of them and is surface!) 2 on holes 1 surface

1x 47 uF 4v diam 4 mm on holes

2x 220 uF 2v diam 5 mm(those i had replaced) on holes

Height for all : 5,5 mm aprox.

I think we have them all this time!

Belt is still fine ! Now i see the real difference with the (old) one in the jx849.

I've checked with 7 mm new caps but it's still too tall ! I think the limit must be 6 mm not more(for the 2 i had changed) , not checked the other ones , do you know the height of new caps please ?

Yup, that is a JX505 mechanism. There seems to be more space on your pcb for caps compared to the 505.

Oh my word, that PC board is a mess! I am in fact referring to the leaked electrolyte all over the circuits. You should really ought to de-solder the PC board from the chassis, remove the capacitors that you intend to replace, then neutralise the acid and clean the PC board; before putting it all back together. If anything it will prevent electrolysis occurring and future component failure or malfunction.

Once the acid gets under the solder mask it can spread very far away from the leaking capacitors as it travels along the copper traces and cause unexplained short outs.

There is plenty of room in this chassis design. I've put 8mm 470uF 2.5V caps vertically mounted into both a PX303 and PX505 and they use the same chassis. The values quoted in the AIWA cap guide that you need are all 5.5mm.

@plop: beleive me , i've tried just now a 7 mm one and it was too tall ! If the new ones are all 5,5 mm height so that's just fine !

I'm not sure what you see is only leakage since it has already got maintenance in the past by AIWA and... me! If you think the PCB is covered by acid where it's dark it may also be just iron ,and it's old yet i don't know if all old pcb should look like this...

I've highlighted the areas of concern in green that look as though they could do with a clean/neutralise. It looks from the photo that the dark crud like substance is either burnt on old flux or dried on crusty electrolyte. The purple ringed area looks like there is wet/sticky electrolyte present.

This part of the circuitry is in close proximity to the audio and remote control lines. Any contamination could cause issues with sound. Perhaps this is why it sounds not as good when you connect the remote controller to your JX303?

The 8mm caps fit exactly leaving a very fine gap, so the next time I get an opportunity to dismantle either the PX303 or PX505 I will take a photo and show you.

You are right , a bit of burn and acid. I remember the Aiwa technician told me the motherboard was very oxydised ,you must be right indeed ,but there's also part of burnt traces. Removing all the MB , may be one day , since it still works well i won't,lots of work...

Here are larger photos(why the site reduces the size?):

http://imageshack.us/photo/my-...s/5/jx303inside.jpg/

http://imageshack.us/photo/my-...09/jx303inside3.jpg/

The black traces around the cms capacitors are acid you think ?

Again i repeat ,the unlikely sound from the remotes is not only with that old Aiwa ,but all devices i had even when they were new ,i've always heard a difference and i dislike it.

Finally you may be right , i think i will clean the whole pcb before soldering new caps.May be i'll try without desoldering the flat cables , i t may be hard but i'll give a try why not. Of course no dish washer in this case...

My idea: closing hermetically the body into a plastic bag so i could bath the board,good idea or not ? .

no you should desolder the flex cables off the board and remove the board from the rest of the unit. I mean dishwashing soap, not a dishwasher (although apparantly some people use one). This is so that you can clean it properly and also not damage the flex.

I do not bathe the board, just let the sodium bicarbonate (baking soda) paste stand on the board for a few minutes, then scrub off, then the dishwashing soap. Then rinse with lots of water. Boards come out sparkly clean after this.

Thanks for your precious advices ! Since only half the board seems damaged by acid , i think i will just try cleaning the bad side ,this is very delicate to unsolder/solder the flex cable ,if ever i damage it ,i can say bye bye to my walkman.

@Cosmos : Removing and fitting the flat cable is not generally that difficult if you are well used to using a soldering iron. The trick is not to apply too much heat as the traces can come away from the flexible cable. I find using something like masking tape helps with positioning the contacts up before applying the solder bridges when re-fitting.

De-soldering the flat cables serves a number of purposes :

The main one is it allows you greater freedom to work with the PC board - removing capacitors, cleaning the PC board etc.

Secondly some of the flat cables can tear or crease/crack very easily. If so, then you will have a lot of trouble repairing them.

Thirdly, without the rest of the walkman tethered to the PC board you are able clean and rinse the PC board without risk of getting the tape transport and other mechanical parts wet.

Fourthly, it is easier to dry a damp PC board on its own without the rest of the walkman still attached.

If you do not feel confident taking on such a task, then perhaps it would be to entrust this to someone who knows what they are doing. It is possible to screw this up if you are not entirely sure of what you are doing. On the other hand, if you have nothing to lose then you can only learn by trying, and this would be a perfect tool to learn with. Either way, judging from the photos the PC board needs cleaning up if only to preserve the traces.

Yes, electrolyte from an electrolytic capacitor contains amongst other things salts and a very weak boric acid. Plus electricity and a salty solution will cause electrolysis to occur on metal such as the copper in the electrical traces on a circuit board. If left long enough the copper will become so thin or come away from the PC board itself.

I've given a serious look to the board(on the photo) and it seems you're right ,i'm afraid a lot of acid has migrate along the board ,i suppose the big vertical has completely leaked all over,we can still see it around it , strange that it still works fine... I promise to clean all this ,i MUST.

Why do electrolytic capacitors that have leaked still work? Well in simplest terms it is because the plates are still being coated with whatever little liquid is still left inside the capacitor. If you get a capacitance meter and measure a good and bad (but working) capacitor and both probably will read close their rated capacitances. Seems ok, yes? However, get an ESR meter and measure them again at cold and the good one will have ESR close to the manufacturer's rated values, whereas the bad one will have a much, much higher ESR reading. When all the liquid drains out the plates inside will dry out and the ESR will go off the scale. All the AIWA walkman I have restored recently which had failed capacitors that I removed; I later tested and all have ESR values beyond the scale readable by the meter.

a bit of cleaning later...

http://imageshack.us/photo/my-...1/jx303aftclean.jpg/

http://imageshack.us/photo/my-...jx303aftclean2h.jpg/

I can definitely see an improvement especially in the areas previously noted to be very bad. For those areas, I can even make out the individual traces now.

If you have horizontal and vertical mounted capacitors, it can be difficult to decide the best position for long term storage of walkman. Personally I favor storing mine door side down, the majority of capacitors are vertically mounted and in this orientation if the rubber seal was to shrink the electrolyte would hopefully still stay in the can or evaporate in that position. Storing them door side up or vertically upright over time could cause more damage as the electrolyte leaks everywhere.

That's a nice idea ! See first post , all 10 caps now fully identified and measured.

Well, I had a spare moment today so I've taken apart my PX505 to expose the two 8mm high Nichicon 470uF 2.5V capacitors which fit comfortably inside.

Thank you ! What are those kind of caps ? Through holes ? I can't see any writings on them ! Believe me those i've tried in the 303 woudn't fit at all ,i'm not sure the space is the same... By the way i've read the 505 had amorphous HX head , i'm not sure it is the case for the 303 yet it has HX head for sure ,that's strange i've heard a so bad sound from it ??? May be it was because i just stepped from an HS-J08 to that 505 ? The J08 was very good ,a colleague had one and i was lurking at it but not enough money at the time... Then one day he sold it to me because... it had troubles ,sadly i never managed too repair it fully but it would work a bit yet , the head alignment gave me a headache ,i now understand why Aiwa would develop the auto azimuth system !!! I will try to catch a 505 one day because it has a nice design. Then i gone to a 303 and was happy with it , the guy who sold it showed me a test : you see that tape deck ? You know what it is ? It's a SONY high end ES. Now listen to both ,amazing ain't it ? Hey ! No difference ! Then i bought it !

I bought these through hole radial capacitors from digi-key. Writing is all on the top. Check out the PX303 bad caps thread and you will a photo of them before they are installed.

493-3806-1-ND CAP ALUM POLYMER 470UF 2.5V RAD

PX303 has amorphous hx head, but the JX303 only has permalloy HX head. Then later, PX505 and also JX505 both have amorphous hx head.

Which rechargeable battery?

There is one in each tuner since the JX303(i presume) ,it's here to keep clock and your presets while you change batteries or charge. There is one thread here about it , the guy changed for a new one and it would now keep datas for a more long time(in weeks!!!) instead of a few minutes or seconds.

You can see it on the JX303(a little bit) , i'll show you a close photo later.

That guy was me and it was a JX707. The battery used in that model is a button cell type and not known for leaking.

Oh that was you ! You're right , i've read the documentation , this is lithium battery not rechageable...

Lithium batteries can be rechargeable or single use depending on their chemistry inside.

So in our case ,no matter if it's recheargeable or not ? Is it recheargeable or not ?

Just have received my caps ! Happy and unhappy too... 18€ shipping and 21€ taxes....+

In the early AIWAs where there is no obvious easy method of removal (for example, soldered to the PC board and hidden away), you can be confident that it would have been a rechargeable battery. Some of the later models AIWA/Sony produced did have a panel for you to remove the single use battery.

Shipping charges are high from Dig-Key, which is why I max out my order to get free shipping. Taxes - well no avoiding that one.

I seemed to have no (free) shipping and about $1 tax from the local element 14, even though some of my caps came from the US/UK...

Next time i'll find a good soul in the US to order for me and resend to my country, even with a little com. for him it wouldn't be that high ,yet i'm happy , those seems very tiny ,i'm sure those will fit perfectly this time.

Is Singapore not still a free port? ie you don't pay tax for a lot of things? This would probably account for the lower tax you'd have to pay.

First part of the job is done ! I have changed that big 220 daddy that emergently needed to be changed(surely the one that had repaint my board...) ,great ,exactly same size ! Replaced those 220 2v with those 220 4v (same as old dad) ,a bit bigger than original 2v but those would fit very well. Now what i get ? I think an increase in basses ,a better sound i'm sure.I'll see later for the others.May be the cleaning also did improved things.Some photos later...

We get 7% tax on everything here except for parallel imported stuff, But I guess since I bought around 80 capacitors the whole bunch cost slightly less than $20. But I'm still curious as to why the local element 14 does free shipping.

It's a great feeling to fix something and make it better isn't it? You are quite lucky as Caps are harder to fit in on some units like the JX 505, of which I had to move a coil and bend some capacitor legs slightly to get everything as flat as possible, because of a lack of space.

Oh yes what a joy ! I suppose you're talking about those 2 volts through holes ? I will try to show some comparison between the originals and what we can get today ,sure those 2 volts are smaller , the 220 4 v is same size and from what i've quickly see the others seems also the same size ,but i'll get a closer look later. I'll can never thank you enough for having pointing me those tiny caps , i've searched for them so many years ,yet i knew we could find them but only in large quantities ,so not affordable for me...

There are even smaller still that will be perfect for Walkman use, plop discovered that Chemicon made a series of shorter caps called the MVS series. Sadly we cannot seem to find any in small quantities online.

Of course smaller sizes exist since a long time , you can easily see them on lots of thing related to PC (dvd burner,PCI boards...) , yet i've never seen such small values as 2 or 4v , i don't know if it has any incidence on sound ? I'm not an electronician but i've always supposed such small values are for lower consumption,what do you think about it ? I asked a technician once but he couldn't answered in terms of sound quality.