Thanks for the news Plop !   Within my holiday last weeks i changed some more caps(not yet replaced all) and it seems some motor hum it had went away.I also noticed that the tape function were not locked when no tape in the player , i will have to check something like the tape detectors or something else , i did not noticed this before and i can't recall if i had pushed any buttons with no tape inside , may be this occured after bathing the mother board. I'll be happy to read your future thread about restoring your 303. Don't know if it's the best ever made in the JX series , 505 is a solid challenger with BBE , and i still find the frequency response improved from the 505 ,but i'll come back on this when my 303 will be fully recaped.

I don't know if you're talking specifically about the 303 , but my european 303 has the step switch for FM tuning located below the door , same for all models i own , even my japanese JX707 has the step switch.

@Minty I don't know what model of AIWA you are referring to, but the JX30 has a tuner that is better than the JX303. The JX303 has a FM frequency range of 88 - 108 MHz whereas the JX30 has a frequency range of 76 - 108 MHz PLUS the TV band with channels 1 - 12.

If anything I find the Sony models the most frustrating as their FM bands are Japan only unlike the AIWA ones that are true worldwide compatible tuners.

Unlikely it is the JX50 either, as it too has a world-wide synthsized tuner, or even the JX70 nor the JX929. All these Japanese models feature digital tuners with FM tuning from 76 to 108 MHz.

Even AIWA's non-digital tuners found on the JL30, JL50, and RL50 also include tuning from 76 to 108 MHz.

It must have been a very old Japan only model, or another manufacturer.

JX303 & JX505 owners , could you please check if yours feature(or not) a lock function when no tape is inserted ? I thought my 303 was faulty but i just figure out my 505 does the same(no lock),just try play or any key related to tape function.

@plop: what kind of battery did you discovered in your JX303 ?

No operation with door open. The tape does not function unless the door is closed. There is a micro switch at the hinge nearest to the battery inside the tape compartment. If it is possible to operate motor without closing the door, then this switch is faulty or something on your PCB circuit is shorted out.

The memory battery on the JX30/303 is the same as the JX70/707 - a CL1220. I replaced with a ML1220, since the CL1220 is no longer in production.

You misunderstood , i was talking door closed and no tape !

So it's a rechearchable too ,thanks for the info Plop.

Yes, the alpha transport will work with the door closed and no tape inside. The micro switch only detects for the door position. Later transport such as the 0ZM transport detect on presence of tape and not door position.

Thanks !

Hello friends and happy new year !

So i've received all my stuff from digi-key now. While i was finishing recapping my 303 ,something wrong appeared , take a look at the pcb , see the two 47uf 4v smd caps , polarity is on the same side for both BUT once i took them off , the pcb shows oposite polarity for one of them !! What's wrong here ?? I will do a test following the pcb marks to see...

edit: well at first glance there seems to be no incidence , i've just listened to the radio fir now. New discover while i was going to change the rechargeable battery in the door , a cap is hidden there and what a cap ! A 220 uf 4v radial (on holes) yes but with a very specific shape ! It's not mounted on the pcb , but inside !! The radial we know are too large ,we must forget those ones , our chance would be the smallest smd possible ,only one of this kind could fit well , all i actually have are too large (4v and 6,3v) , i should check at digi-key if they have something that could fit. I n fact that particular cap is thin but long. I'll show some pictures later , now i must change that battery... Size of that cap : must not exeed 4 mm in diameter and 12,5 mm lenght.

edit2: now tell me why things are never made like we would like... You have to work the pins to fit ! In fact things are reversed here...

edit3: oh surprise! Not powered yet anyway and i can see a nice switched on display ! ^^

edit4: oh no! The power off switch is loose... must open again !

edit5:now changing the cap in the battery pack , very light corrosion here but i can even see some traces on the motherboard ,even if very light i will change it , very easy to do.

Please JX303 owners , would you check your motherboard about the 47uf 4v caps ? I couldn't find any incidence in playback , recording , DSL ... it seems they are related to DSL but DSL is OK , i've read that polarity should absolutely be followed or they could leak or explose so i just don't understand...

edit6: how are you doing Cosmos ? I'm fine thank you !

Well well well , with full recaping it now sounds very close to the JX505(talking radio not yet tested tapes),that meran sweet sound ! That's a good thing. Now , is that the left few caps i needed to change (the 3 smd) or that cap with reversed polarity ?? I know it was serviced back in the days but really in the early 90's , i don't know what they did but the caps semt they were original, soldered buy a machine not a human and they were stinking ! I think i will keep the new one like i soldered it ,according to the motherboard specification. Well that thing finally sounds great !! The three smd caps had leaked of course , now my 303 is like new , there's still that tuner cap that i'll change in the future , got to find one that fit , many thanks for help everyone here !  And stay tuned for pictures coming soon.

Finally those three last caps that were replaced improved the frequency response , so finally not a bad idea to replace them all even if you think there's no trouble here !

Time for some photos.

All caps replaced:

Note that one of the 47uf 4v has since been replaced like it was originally.

Old cap from the battery pack.

I changed it even if there were no trace of leakage but i always found some corosive white traces inside the JX303 near the connectors...

The tuner with it's old recheargeable battery and the last cap that wasn't replaced.

Other side:

There is something i still need to restore , the volume pot... It was fine but it seems it didn't loved to be washed , it was fine after i washed the board but time later troubles appeared , i desoldered it to clean the board under , the familiar smelt was here in the solder... i used my spray on it(the pot) , spray that's made for that purpose but this time it didn't worked ! Still a lot of crackling , the best would be to open the pot but is that even possible ? Any solution Plop ?

I use Caig DeoxIT D5 spray. Cleans volume potentiometers up nicely Of course you need to have carbon on the trace for the wipers to ride on. If the carbon traces have completely worn out then, short of a miracle, no spray is going to prevent crackling.

I normailly remove the volume pot when I wash the PCB to avoid situations like this. If you are getting crackly sound from the pot since washing, then it is likely that some of the sodium bicarbonate may have gotten inside where the traces run. I suggest you carefully remove the pot and rinse through with warm water whilst working the switch, let it dry and then generously lube with the Deoxit whilst working the switch before attaching back to the main PCB. Or if you want to cheat, just swap it out for one that is not crackling. These potentiometers are quite common throughout the AIWA models, and if you have a scrap unit it can be donated from it for use in your JX303.

D5 deoxit has solvents to allow a flushing action. D100 deoxit is pure contact cleaner.

Thank you Plop ! You're surely right , i didn't turned the pot while washing the board , i will give it a try. I'm using an equivalent of D100 , didn't know there was stronger chimical.

I removed the volume pot again today , washed it this time ,turning it a lot , then i used my spray again whan dry of course(a lot more!). I still have some crackling yet a bit less , i will wait a few days to see how it will behave , next time i change it if really damaged !

Well from what you describe, it is improving. Although do bear in mind that sometimes the carbon tracks do wear out unfortunately and when they do, no amount of cleaning and lubricating will solve the crackling.

No, it's just back to the same point as it dries ! Strangely only one channel has the issue and i can tell you the pot was fine before i decided to clean the board so my advice would be not to clean it if fully functionnal but remove it since it's very easy , use only the deoxyder ,no water , no baking soda ! I sometimes wonder if it is really the pot but i'll be sure once i 'll find another one.

If it starts to crackle as it dries, then that suggests whatever you are using to lubricate it is evaporating and not actually protecting the carbon trace. Perhaps it only cleans the trace?

The washing action may well have accelerated the wear rate of a weakened carbon trace on that channel.

I don't generally 'clean' the potentiometers. Although I use the DeOxit D5 product claims it has a flushing action it does leave behind a non-evaporating residue of DeOxit to coat the switch. Repeated applications of DeOxit serve to coat the switch where it may be insufficient.

The spray i use (sorry there's no english on it so here's a translation:TOP CONTACT by TECHNITOP/FAREPRO(the only english on it..) cleans , lubricates , contacts deoxyder. I won't translate it all but this "removes potentiometer cracklings". As i said , it was successfully used on other hi-fi component pots , the difference here is pots were never dish-washed or in contact with sodium bicarbonate ! I suppose this is the thing not to do with pots.But you'll say why not both channel in that case.... I had improvement yes at the beginning each time but not completely so i don't know if i should buy the same spray you use unless it's cheap wich i doubt or change the pot ? If you're aware of wich cheap models use the same pot just let me know , i know the J303 has the same but better look at some cheaper player only.

I have never heard of this Top Contact product. Since it is licenced for sale in EU then you should be able to obtain a copy of the MSDS (Material Safety Data Sheet) produced by the manufacturer. This will give you an idea as to what may be in the can. You should expect to see volatile solvent, propellant, and the active ingredients. The first two would evaporate leaving just the active ingredient as a residue.

As to the sodium bicarbonate. It is a very effective cleaner, and will strip oils grease etc. Washing in dish water will not help either as detergents will also strip any oils or grease from switches.

From memory the volume pot for the JX303 is located on the edge and has the numbers on the side of the dial and not on the top like say on the JX505. There are a wide range of AIWA models that use this pot, from memory some that come to mind are J101, PL303, PL505, JX707.

Ok, I think I found the MSDS for this chemical spray

http://www.fareprodirect.com/s...s/TDS-TOPCONTACT.pdf

My french is not that great, but from what I can gather this is a very crude switch contact cleaner. It would probably be fine for metal to metal contact switches eg door bell switch, not so sure of its effectiveness for carbon based switches.

This is made too for electronics , it's written on it ,it's a big spray for proffessional use ,i'm sure it's good but as you said some carbons traces have surely gone , when and why i couldn't tell but not due to the spray since it began before i used it. I guess it's rust inside du to contact with water , don't know if that's possible but could be a clue.

Sorry , forgot to tell , yes it is the pot with marks on the thin wheel, not on the side(like large wheels) , but you can look at your own JX303.

I certainly can look at my JX30 when I am at home, but not when I am in the office which was where I was when replied to you earlier.

Back home those days , i've tried my 303 with the remote and there was no issue with crackling sound so this confirm it is only the pot , i've found C:FR:3160" target="_blank">this on ebay and it should be fine.

I have a J505. Nice mid-budget, non-logic controlled AIWA walkman with HX head. It is a nightmare to get inside, as there are many screws and complex interlinking pieces of plastic. Once inside, it has a very high surface mount electrolytic capacitor count.

I have received today the J505 , you're right , nice little unit , similar to the J303 with a better design ,there is still life in this little unit , i'm sure just a cap problem ,now i will need another one for parts to try this one... As you said , not easy to get inside but not yet fully opened , i think i will have to remove the door to get inside access without desoldering , board is clean outside , just some rust here and there on the metal body , will check this later. The issue with it is that it powers but the sound is weak , if you turn the volume pot ,you can hear a noise in the headphones telling you(i suppose) the caps are weak or dead , nothing like crackling(nothing to do with the volume pot) , but i'd be curious to hear how that thing sounds.

edit: there seems to be a problem now , i've exchanged the volume pots in my 303 and there are no more cracklings but... it acts as a balance pot.... so i suppose it is is not the same board ! Yet they look identical ,may be should i try to rewire it properly on the 303 board but how...? How could i figure out what the pot board looks like ? Any idea ?

Ok from what all look like , pots , walkman boards , all is inverted ! On the walkman boards , there's always a big soldering pad for the largest track on the volume pot , to the right on the 303 and to the left on the 505 , that should be a good clue to know wich pot should work on a given walkman , i will check if i can find a picture of a J303 opened... I really wonder why Aiwa did such a thing ??? They are physically identical but board is reversed , just crazy !!

edit 2: answer should be here :

http://v-96.blog.163.com/blog/...6415201061391930850/

edit 3: and answer is.... not good...

edit 4: hey Cosmos! Look at this picture from the 707 :

http://media.photobucket.com/i...djrivera680/aiwa.jpg

seems to match ! See , there's even marks on the board to help you ! See how completely reversed it is ,now you should be able to rewire this with success , hey! Almost two soldering points are matching ,good !

edit: No , i'm wrong , if it's reversed ,only the center pin will match.

Gotta try this. Oh thanks Cosmos for great help you provided. Where's our friend Plop ??

I finally made it ! First i've left the four pins exepted the center one on the volume pot, soldered 4 little wires ,protected the board with some tape , rewired properly , soldered the center pin and against all odds the little mess fits well inside ! Here is so a good way to re-use those volume pots from cheaper models. Now i can use my perfectly working JX303 while waiting to put my hands on a cheap matching model.

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Good job there

Who would have thought it? So a J505 has a volume pot that is actually a balance pot for a JX505.

Thanks Plop ! But do not mistake , if it acts as a balance pot , the center position will blow away your eardrums....

Hello Vrai and welcome to the forum.

How badly leaked on was the circuit board? Some JX303s can be quite badly affected.

What you are describing is very common when trying to replace capacitors on AIWAs of this particular vintage.

The fact that the unit does a mechanical reset sequence is quite positive. From what you describe, part of the problem lies in the remote circuitry as all control is diverted to the remote controller when the switch is set to remote and in your particular case it is stuck in "remote mode". Trace the circuitry from the remote switch for corrosion/contamination.

The erratic logic control is something I see very often on AIWAs with leaked capacitor acid. To remedy this you will need to carefully clean the board again as it would appear that there may still be contamination on the board. Moisture from even just breathing on the contamination can short out the PCB. Check also for dry solder joints too, once you've cleaned the board. These will need to be corrected. Also check for oxidised solder joints. These solder joints will look much darker than the dry joints almost Lead(Pb) like in colour, and will be very difficult to melt at first they may also be corroded in state as well. These will need to be corrected also. Be careful when re-melting badly oxidised joints as there is potential to lift traces or burn out components and their connectors with too much heat.

Basically the unit thinks it can only select either 'REMOTE' or 'HOLD'. I have found that alcohol is not effective for cleaning the capacitor acid. You will need to neutralise with sodium bicarbonate (bicarb of soda). All the alcohol seems to do with it is spread a thin layer of it about.

I have a circuit diagram somewhere, but I am at work at the moment and it is at home.

I found a local copy of the circuit diagram and posted it into the service manual thread here -> index.php?board_oid=193392314111653483&content_oid=263906035089896803

Hi vrai-lxi ,

if you decide to clean the board with baking soda (sodium bicarbonate) you MUST ABSOLUTELY remove the volume pot or you'll destroy it like i did ! Only deoxyder spray on this nothing else ! I've you checked the flat flex cable to the door ?

No worries, let us all know on the forum how you get on.

I had a slightly different power issue on a RL50. Cleaned it all up. Applied power and ... nothing! I didn't have a circuit diagram, but I had a second RL50 generously gifted to me. It was from that second one I was able to trace back every point of the board to a part of the +2VDC line that went under the reverse switch at the bottom where the battery pack clips on. When I removed the switch I found capacitor acid had completely eaten away the copper trace.

If a via is broken, then you could either flood the via with solder or pass a thin piece of wire either side to bridge the open line.

I finally got time to get inside my J505 , it was all recapped , board was seriously damaged yet behind some caps ,i even broke traces but i could get loud sound again from it , unfortunatelly could'n get any sound back from the FM mode ,i've checked and checked again the flex cables but they were fine , i suspect some broken traces behind the caps , or may be the use of larger capacitors when smaller 2 volts are unavailable , i will have to work more on this one. I made re-use of the JX303 volume pot with the same trick because the original is in my JX303...  So i could hear what the unit had to give. Very good unit indeed.In fact it has been my guinea pig to train myself desoldering the flex cables....

If you are not getting sound from FM mode, do you get sound from AM?

If you get no sound from either radio modes, then it is likely an issue with the audio from the radio board getting to the the pre-amp on the main board. Trace the lines from the radio board all the way through to the pre-amp ensuring that there are no breaks in the traces. It is possible that acid may have corroded them.

If you get sound from AM but not FM, then it is probably an issue with the FM circuitry on the radio board. Probably a cold solder joint somewhere on the radio board.

Basically i had FM sound before i put my fingers inside.Weak but there.After works, this is the only missing thing , AM sound is alright. Surely a broken trace. It's not easy to follow traces on the boad with their paintings on it but i will try nex time. The flex cables beeing checked.The display shows that it searching for radio station but no sound at all , i was not in town so couldn't tell if it would tune something or not but manually tuning i couldn't hear any radio stations when they are available(tested fine with my 707) ,just a very weak noise when volume pot is to the max,but the beep-beep sound is here and strong.

I just had a thought. It could be a problem I've seen before... but this was for a manual tuner whereas yours is a digital tuner and could be muting out the white noise thereby causing you to think that there is no sound.

On the main PCB, there should a tightly coiled copper wire. This is a designed to allow radio waves through, but nothing else. It is connected at one end to the headphone socket ground pin and at the other end the FM tuner. It effectively is the bridge to the antenna for the radio via the headphone cable.

I have seen a few of these develop dry joints, especially where a lot of capacitor acid is concerned. Check the connections are good on yours.

Thanks , i'll check that , if you could point me where to check ,that would be nice.