It is pretty much given that with AIWA personal stereos as they age they will very likely suffer from failing capacitors.

Failed capacitors can adversely affect the sound quality and performance of a player and at the other extreme cause phyiscal internal damage or worse still short out and cause another circuit to malfunction or fail. The most obvious indication of such a problem is a reduced output from the power amplifier. Other effects can be reduction in bass, noise, or erratic performance from logic controls or signs of rust in the case. Opening the case to examine the main PCB can reveal clues as to failed capacitors with leaked electrolyte on the traces and nearby components as well as corrosion on metal parts. This does depend on how the unit was stored as to the extent of the damage if any on the main PCB. ESR meters can be bought or built to test capacitors in situ on a clean PCB.

Generally if one component is failing the rest are probably not far behind. A few cents / pence saved from not changing them all at once could lead to PCB damage later on as the problem goes un-noticed. Also for some models there are additonal stresses to the PCB where points need to be desoldered and resoldered to gain access. These solder points could get weakened or damaged in subsequent repair attempts.

I have a number of AIWA models and have found that replacing the failing capacitors usually brings a poorly performing unit back to the way AIWA intended them to perform. Locating parts has been a real headache but fortunately to repair AIWA models it is relatively straightforward to swap out as they stick to a common set of capacitance values, so it should be possible to build up a generic stock capacitors to fix most of them that are out there.

However it isn't as easy as that, the most problematic of values to source are 2V rated capacitors. I do not know of any manufacturer that still sells electrolytic cans with this rating. The nearest rating with a range values in the surface mount form factor is 2.5V by Nichicon, but even then the 100uF 2.5V is too big, in order to replace these a 100uF 2.5V tantalum is required. For through hole capacitors it is possible where space permits to replace with for example a 100uF 4v for through hole locations or failing that to substitute those for a tantalum surface mount.

Power amplification circuits used by AIWA generally use through hole capacitors for DC voltage blocking (presumably these were better spec at the time?), there are exceptions to this rule such as the P50 and PL50 where the entire inventory of capacitors is surface mount based. Replacing these can improve the low volume issues. Values for DC blocking capacitors in power amplification circuits in AIWA that I have found are 220uF, 330uF, and 470uF. The bass profile can effectively be tuned depending on the value selected, with the higher the value the lower the bass roll off from the frequency range. It is my experience that if you are getting a quiet output from your AIWA it is more likely the smaller values on the pre-amplifier circuit that have failed, but do also check the DC blocking caps too. I have a PX10 which had a failed DC blocking cap preventing any audio on the right channel. Ultimately test equipment such as a capacitance and ESR meter will confirm their health. If you are stuck between choosing one to buy of the two, I'd highly recommend the ESR meter.

This is a list of AIWA models with the capacitance values and quanties located on the main PCB along with some repair notes.

PX10/101

No desoldering required to gain access. Note the two 220uF 2V between the headphone and remote jacks will need to be replaced with something of equal or smaller physical size owing to the chassis design. Tantalums are probably not an option as both capacitors are on the audio path. A long thin shaped 220uF 4V is required in one location

(Through hole)

47uF 2V       - 2

100uF 2V     - 1

220uF 2V     - 4

47uF 4V       - 2

220uF 4V     - 2 (+1 long shaped)

PC20/202/202MII/202MIII/203/204

No desoldering required to gain access. 100uF and 220uF 2V values can be easily substituted for larger 4V ones. Watch out for a couple odd ball values used in this model.

(Through hole)

100uF 2V     - 2

220uF 2V     - 2

47uF 4V       - 2

220uF 4V     - 2

22uF 6.3V    - 1

4.7uF 16V    - 1

JL30/303

No desoldering required to gain access. One capacitors is horizontally mounted.

(Through hole)

47uF 2V       - 1 (horizontally mounted)

220uF 2V     - 2

47uF 4V       - 2

220uF 4V     - 1

Surface mount

47uF 4V       - 1

220uF 4V     - 2

JX30/303

No desoldering required to gain access. Two capacitors are horizontally mounted.

(Through hole)

47uF 2V       - 1 (horizontally mounted)

220uF 2V     - 2

47uF 4V       - 1

220uF 4V     - 3 (one horizontally mounted)

(Surface mount)
47uF 4V       - 2

100uF 4V     - 1

PL30/303

No desoldering required to gain access. Watch out for the two 10uF 16V capacitors.

(Surface mount)
100uF 2V    - 1
330uF 2V    - 2
47uF 4V      - 4
220uF 4V    - 4

10uF 16V    - 2

PX30/303

No desoldering required to gain access. This model uses also 22uF 6.3V, for which there is a modern day direct replacement available. Replacement through hole 470uF 2.5V will just about fit without bulging the PC Board if vertically mounted

(Through hole)
470uF 2V     - 2

(Surface mount)
100uF 2V     - 4
220uF 4v     - 4
22uF 6.3V    - 2

PX410

Two solder points for the solenoid required to be desoldered in order to gain access. 100uF 2V are very tightly packed together, therefore may need to be substitued with tantalums.

(Through hole)
100uF 2V    - 4
220uF 4V    - 5

(Surface Mount)
220uF 2V    - 2

F50/505

No desoldering required to gain access. One 10uF 16V surface mount capacitor. Optional external speaker also requires two 220uF 4V surface mount capacitors.

(Through hole)
220uF 2V    - 2
220uF 4V    - 1

(Surface Mount)
47uF 4V     - 4

100uF 4V   - 1

220uF 4V   - 2 (+2 for speaker)

10uF 16V   - 1

P50/505/505MKII

Two solder points for the solenoid required to be desoldered in order to gain access. 100uF 2V surface mounts will need to be substitued with tantalums. Tricky plastics to remove when disassembling.

(Surface mount)
100uF 2V    - 3
220uF 2V    - 2
220uF 4V    - 4

JL50/505

No desoldering required to gain access. 100uF 2v and 220uF 2v can be substituted for 4V values.

(Through hole)
100uF 2V    - 2
220uF 2V    - 2
47uF 4V      - 2
100uF 4V    - 1
220uF 4V    - 3

PL50/505

No desoldering required to gain access.

(Surface mount)
100uF 2V    - 1
330uF 2V    - 2
47uF 4V      - 3
220uF 4V    - 5

RL50

No desoldering required to gain access.

(Surface mount)
330uF 2V    - 2
47uF 4V      - 5
220uF 4V    - 6

EX50 JX50/505/2000

No desoldering required to gain access. 100uF 2v and 220uF 2v can be easily substituted for 4V values.

(Through hole)
100uF 2V    - 2
220uF 2V    - 2
47uF 4V      - 2
100uF 4V    - 1
220uF 4V    - 3

PX50/505

No desoldering required to gain access. Replacement through hole 470uF 2.5V will just about fit without bulging the PC Board if vertically mounted. Contaminated PC board can cause logic control malfunction, if this is the case it will require meticulous cleaning.

(Through hole)
100uF 2V    - 3
470uF 2V    - 2

(Surface mount)
100uF 2V    - 1
47uF 4V      - 1
220uF 4V    - 4

J55/505/505MKII

If you like 3D jigsaw puzzles and undoing screws in a certain order you will love servicing the J505. Otherwise, this is a nightmare unit to get into with at least six different types of screw you will encounter.  Remove the two screws holding down the main PCB and lift the main PCB free from the chassis first before attempting to remove the middle plastic outer cover. Watch out for a small plastic washer that fits directly below the screw nearest to the headphone socket when lifting the main PCB. Remove also the two screws holding the cassette door and the screw holding on the hinge lock plate to enable the cassette holder to be released from the chassis so that the main PCB can be opened.

No desoldering thankfully required to get into the unit - So get screwing!

(Through hole)
220uF 4V    - 1

(Surface mount)
100uF 2V    - 1

220uF 2V    - 2
47uF 4V      - 2

100uF 4V    - 2
220uF 4V    - 7

22uF 6.3V   - 1

JX70/707/909/929/3000

Probably one of the most difficult and delicate AIWA to service internally. Eight solder points to be desoldered. Two solenoids with two points each and also four points on the motor. Playback solenoid is easily deformed/damaged by heat. It is highly advisable to change the belt at the same time to limit the amount of access required to this part of the unit.

(Through hole)
220uF 4V    - 2

(Surface mount)
47uF 4V      - 2
100uF 4V    - 1
220uF 4V    - 3

PL70/707

No desoldering required to gain access. Detach the brown solenoid wire stuck down over the main PCB to free main PCB from tape transport.

(Through hole)
47uF 2V      - 1
100uF 2V    - 1
220uF 2V    - 3
220uF 4V    - 3

JX849

Seventeen solder points to be desoldered. Seven for the motor, three either side on the switch side, two for the playback solenoid and two for the record solenoid.

(Surface Mount)
47uF 4V      - 3
100uF 4V    - 2
220uF 4V    - 3

PX1000

Similar difficulty to JX70 series to dismantle, will require soldering iron for disassembly. Watch out for easy to damage by heat solenoid.

(Through hole)

220uF 4V    - 3

(Surface Mount)

22uF 6.3V   - 2

47uF 4V      - 1
100uF 4V    - 1
220uF 4V    - 1

This is a list of suggested replacement parts (All parts are located from Digi-Key). Of course it is worth double checking with Digi-Key these parts are still current or that the specifications are suitable for your use before you order.

If anyone else knows of somewhere else that has a cheaper range of parts please do shout out so that we can all share in this knowledge. For worldwide orders Digi-Key do not charge for postage once it exceeds a certain value. For UK that happens to be 50GBP. I recommend using FedEx as the preferred courier as you do not get billed the tax for the "free delivery" unlike UPS who not only charges a handling charge, import duty on the items BUT additionally (not mentioned) import duty on the delivery charge. 

100uF 2V surface mount

Substitute with

399-5144-1-ND CAP TANT 100UF 2.5V 20% SMD

220uF 2V surface mount

493-3816-1-ND CAP ALUM POLYMER 220UF 2.5V SMD

or

399-4808-1-ND CAP TANT 220UF 2.5V 20% SMD

330uF 2V surface mount

493-3817-1-ND CAP ALUM POLYMER 330UF 2.5V SMD

100uF 2V through hole

No direct replacement available

Where space permits swap out with 100uF 4V or 100uF 2V SMD

220uF 2V through hole

No direct replacement available

Where space permits swap out with 220uF 4V or 220uF 2V SMD

470uF 2V through hole

I have not been able to source a 470uF 2V in exactly the same dimensions as the original through hole, but these can replaced with a Nichicon 470uF 2.5V and these fit perfectly in the space vacated by the original albeit a touch taller.

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

4V through hole

P952-ND CAP ELECT 47UF 4V KS RADIAL
P953-ND CAP ELECT 100UF 4V KS RADIAL
P954-ND CAP ELECT 220UF 4V KS RADIAL

4V surface mount

These are all 6.3V values, but they are shorter and have higher endurance than the 4V Panasonic previously suggested. Thanks to Bub for suggesting these instead.

565-2056-1-ND CAP ALUM 47UF 6.3V 20% SMD
565-2057-1-ND CAP ALUM 100UF 6.3V 20% SMD
565-2058-1-ND CAP ALUM 220UF 6.3V 20% SMD

6.3V surface mount

493-2083-1-ND CAP 22UF 6.3V ELECT WX SMD

6.3V through hole

P955-ND CAP ALUM 22UF 6.3V 20% RADIAL

16V through hole

P974-ND CAP ALUM 4.7UF 25V 20% RADIAL

16V surface mount

493-2099-1-ND CAP ALUM 10UF 16V 20% SMD

Hi,

Thanks for your detailed description of changing capacitors on AIWA cassette players.
I just purchased an AIWA HS-PC202 MIII player in mint condition. It works, but the sound output is very low. Probably the capacitors of the pre-amp are leaked. Do you have an info, with which capacitors I can replace them?

Thanks and best regards

kerni99

Hi Kerni,

Strangely when I reviewed this thread I had realised that I had omitted the data for the PC20 series, but subsequently forgot about adding that data.

I do have the information at home, and will update it when I get home later now that you have reminded me.

I've added the PC20 series capacitor inventory list as requested. There is no direct replacement for the 16V capacitor, but the 25V is a suitable replacement.

Capacitance substitutions

I previously touched on capacitance values and sometimes where they are no longer available. It is generally possible to substitute one for another, but there are a couple of basic rules that apply.

If a known previous value is no longer available say for example 90uF 2V then we can substitute for a larger voltage rating ie 90uF 4V or we can substitute for a larger capacitance value ie 100uF 2V. A point to note is that in the second case we should not oversize the capacitance value as this may adversely affect the circuit design such as say using a 470uF 2V in the previous example. Swapping in a 100uF 4V would also be acceptable. In any case lesser values should never be substituted as this could have catastrophic results.

Another issue with replacing with larger valued capacitors is that inevitably the physical size will also increase too, and considerations have to be taken to allow for the increase in size and whether it will fit into the space vacated by the previous capacitor. Usually where space is very limited and no alternate small sized aluminium electrolytic capacitors are available the alternative is to use tantalum capacitors. Care must be exercised when installing tantalums as they can be damaged by excess heat and can also explode violently if their polarity is reversed. Another point to consider, is that some circuits are not suited to the characteristics of tantalum capacitors ie audio path may have undesired colouration due to the application of some tantalum capacitors there.

Added capacitor inventory for AIWA HS-F50/505.

ESR Meters

Previously I touched on the use of ESR (Equivalent Series Resistance) Meters in an earlier post. These measure the amount or resistance in a capacitor. They differ greatly in operation from regular Ohm meters found on DMMs (digital multimeters). Without getting too much into the fine detail, you can use them to measure the resistance of an electrolytic capacitor to determine their usability and health. This is despite whether they are bulging or leaking acid.

Electrolytic capacitors in an ideal world should exhibit zero resistance, however in practice this is not always the case. Even capacitors with low ESR values will have <10 milliOhms of resistance. Typically, with aluminium capacitors that are low voltage such as the ones commonly found in walkmans they will not be as low as this. Some tantalum capacitors can be as low as this however. For example a good 220uF 4V Panasonic aluminium capacitor can read as low 0.2 Ohms. Even 20 year old Nichicons with the same values have read as low as around 0.7 Ohms. There is no correct value for what is a good ESR value or bad one as values vary greatly from one manufacturer or variant. More rather it is to do with resistance range. In other words if the values read were more of the range of say 15 Ohms, then it is probably safe to say that the capacitor is suspect.

Getting a good ESR reading can also depend on operating temperature, and to test ESR it is best to do this on a cold component. Warming up components can give a false positive reading. ESR can be determined with capacitors still in the board so long as they are not "wired" in parallel in circuit. In such situations it would be wise to disconnect at least one leg from the circuit and re-test. As a final check, testing the capacitance with a capacitance meter will give an indication of whether the capacitor is still within the stated discharge value. This test usually is best done out of circuit for accuracy.

There are a number of products available for purchase from UK, USA and Portugal. Some of these are also available in kit form. The latter two are based on designs by Bob Parker, an Australian technician who rose to fame in the electronics world in the late 90s for first highlighting issues with ESR in capacitors and also bringing out some of the first self build kits to market. Bob has a much better explanation of how rising ESR in capacitors affects circuits in this construction document he wrote here at http://members.ozemail.com.au/~bobpar/k7214.pdf

The Blue ESR Meter from Anatek Corp. in USA is his latest design and is available direct from Anatek Corp. either pre-built or in kit form at http://www.anatekcorp.com/blueesr.htm

The EVB Meter is based on the original meter that Bob Parker designed and is available from Portugal. This is the cheapest out of the mention three meters. In kit form it also represents very good value for money. I bought this kit form from EVB and it took about one and half hours to construct it. By default two diodes are included in the design to prevent accidental discharge damage of the device, but this feature prevents testing of battery internal resistance, however these diodes can be omitted if the battery testing is required. http://clientes.netvisao.pt/greenpal/evb1.htm

Finally there is the ATLAS ESR60/70. This is widely available from Maplins in the UK and also from the manufacturers Peak Electronic Design direct. This device is able to measure the capacitance as well as the ESR of the capacitor in circuit. However this unit will only measure up to 20 Ohms resistance as opposed to 99 Ohms with the Bob Parker designs and requires 12V over the 9V with the other two. http://www.peakelec.co.uk/acatalog/jz_esr60.html

Update : Added capacitor inventory for PX10/101 and PL30/303 models.

Update on postal charges

Since putting in a very big order to Digi-Key recently I was given the option of being able to select FedEx as an alternative courier. As Digi-key offer free shipping for orders over a certain amount, shipping was free in this case. When my VAT (sales tax) notice arrived from FedEx a week later (Note : UPS took one month ! ), I was NOT billed the tax for shipping (unlike UPS).  As expected I was required to pay for the VAT in UK and also a handling fee of 10GBP, which is comparable to Royal Mail demanding 8GBP for shipments via them. Shipping took only 2 days to complete from USA to UK.

In future I will continue to use FedEX and recommend others to do so too if ordering from Digi-Key.

Hi plop,

Yesterday I finished recapping my PX410. I found that it needs not 4 but 5 pieces of 220µF through hole caps (at least for my device). The 100µF's were really tight. They stand criss-cross, but it could be reassembled. The PX410 sounds good now, but not as good as the JX707.

I just double checked the photo of my PX410 circuit board and can indeed see five 220uF through hole capacitors.

Well spotted you pass the test of paying attention. As a reward, I have corrected the error.

It's strange. The PX410 by all accounts on paper should be a really great sounding walkman, but I find it is slightly above average to listen to. It just doesn't seem to engage me with the excitement like say a PX303 or PX505 nor does it have the transparency of a PC202. I'm not sure what it is that it lacks, but I agree given the choice of the two I'd reach for my JX707 over the PX410.

Updated with details for JX30/303 and JX849.

Thanks to Cosmos99 for the inventory

Update : Added capacitor inventory for RL50 model.

Update : Added capacitor inventory for JL30 model.

Update : Added capacitor inventory for PL70 model.

Updated with details for J55/505/505MKII

Hey Parkashan,

Thanks for the heads up on the J101!

I have a broken J101 somewhere. I bought mine from new when it first came out. It was a great little walkman, but sadly mine spent a lot of time in the workshop for one reason or another and when mine last broke it was replaced by a brand new JX707.

I miss the infos about the battery packs caps ,anyone did checked them ? I'd like to buy some replacement caps just in case.

edit: many units share the same shaped battery pack , we suppose the inside is the same ? Some examples : JX303 and JX505 ; JX849 and PX747

F505 speaker battery pack requires 2x 220uF 4V surface mount

Alpha transport series requires 1x 470uF 4V through hole

OZM transport series requires 1x 220uF 4V through hole (I think, from memory)

Thank you Plop. Any infos related to size ? Alpha for JX505 AND ozm FOR jx707 if i remember well ? What about the JX849 series ?

JX303/505 battery holder(unscrew to open) : 1x through hole capacitor 470 uF 4v height 7 mm diameter 8 mm

seems unavailable at digi-key ,i suppose could be replaced with a surface mount with wires ?

http://search.digikey.com/uk/e...93-3991-1-ND/2327129

there is also this one through hole but 6,3v and 8 mm height ,i can't tell if it would fit or not right now.

http://search.digikey.com/uk/e.../565-3254-ND/1948051

JX849 battery holder clipsed so i won't check.

Warning people ! If you order at Digi-key ,have riched the amount for free shipping AND have backorder parts AND ask for multiple shipment they will charge you twice the expensive shipping ,you will be charged twice the expensive custom taxes ! And they don't tell you...

Luckily i've asked them just after ordering if i wouldn't pay twice the custom taxes and they told me at least they would charge me twice the shipping because each order is less than the free shipping amount.Last time i ordered i paid 18€ shipping + 21 € taxes... crazy.... So i asked for single shipment but i'll have to wait my order till end of december.... Very long but not far from 40€ saved...

RE: Digi-Key

Being another overseas customer, I have to say I find it a real pain to order things from them too sometimes. However, since they are a one stop shop for many hard to find electronic components and allow purchase of these in smaller amounts, they virtually have a monopoly on the market and can pretty much dictate the terms of sale and shipping.

I have found that I have to hold back on performing some repair projects, just so that I can accrue enough parts to order so that I can avoid the shipping charges. Life would be simpler if I knew someone in USA that could receive the parts and forward them on through regular USPS. For the sake of convenience I am "reluctantly willing" to pay more for their extensive parts inventory.

I have found Mouser as an alternative to Digi-Key, but their range is not nearly as extensive as Digi-Key's and some items are not as cheap as Digi-Key either.

Although people are very nice there and reactive(phone or e-mail) the shipping remain expensive yet it's quick , i could have asked a friend in the US to receive my order and resend to France but i needed it quick beeing on a holiday. Plus they told me i had to order again(my long parts list) in $US for that.And finally i'll have my order on the end of december... But you're true ,they have hard to find parts ,that's the positive point.

Updated with details of JL50/505 model.

Updated with inventory for AIWA HS-PX1000. Thanks to S2G member Pawel.

Hi, Plop.

Please update your post.

PX20

No desoldering required to gain access. 

(Through hole)

47uF 2V       - 2 (horizontally mounted)

100uF 2V     - 1 (horizontally mounted)

220uF 2V     - 3

47uF 4V       - 2

220uF 4V     - 3 (+1 long shaped)

One more

JX10/101

No desoldering required to gain access. There are 3 long shaped 220uF 4v. Because of very "tight" PCB almost every cap in horizontal position.

(Through hole)

47uF 2V       - 4 (horizontally mounted)

100uF 2V     - 2 (1 horizontally mounted)

220uF 2V     - 2 (horizontally mounted)

47uF 4V       - 1 (horizontally mounted)

220uF 4V     - 3 (all long shaped)

(Surface Mount)

47uF 4V      - 1