Aiwa HS-PX310 Restoration

I want to get my old Aiwa HS-PX310 workign again. The original issue back in 1994 was that the play / stop buttons stopped working - it worked by opening up the back and flicking the elctromagnetic switch bit.

Recently I've been thinking it would be good to fix it, now it also hums! In fact they all hum.

I've collected three other units, been reading this and other forums and have ordered caps, belts etc. I also ordered some hot tweezers after struggling to remove the old SMCs with a normal iron.

Progress reports to follow...advice greatfully recieved!

 

Also - I’m after the service manual for this - does anyone have a pdf of it or know where one is? Thanks

 

I've started work on one of the practice machines. It's actually the one in best condition but the play and stop buttons don't work - I'd love to know why this is as this seems to be a common fault. The issue can be overcome by flicking the actuator inside instead of the electromagnetic switch which is meant to do this.

Because my magnifier hasn't arrived I only replaced the larger capacitors which are fixed through the board - I have exact replacements for these. I think most of the problems are with the plastic based SMCs which I can see some have leaked.

I left the battery plugged in overnight and they have been drained flat even though the motor is not going etc - why would this happen?

I could really do with the service manual - does anyone have one for the HS-PX310 / 510?

 

I can't find a service manual anywhere - not even to buy... But I have found one here to download, but I can't speak or read Russian - would someone who can understand Russian be kind enough to download this for me? I think it involves answering some simple electronic questions for verification... Thanks!

https://remont-aud.net/load/audio/aiwa/aiwa_hs_px310_hs_px510/42-1-0-66698

 

Thanks Mister X - had a looks at My Mate Vince chanel - some really amazing stuff!

 

Today I tried to get the two remaining good 310's (ones where the play buttons function) working. They both buzz and have very faint music when turned to max. I ordered new belts from Germany, they are tiny in section and cost quite a lot. The bigger cheapo ones actually work quite well, but I wonder if there's a downside to using them?

I've always used an Antex soldering iron but bought a soldering station off eBay with hot tweezers - it cost about £90 and works very well - epsecially for removing SMCs. I also bought a lense with led light around it (this was excellent) and a tin of flux.

With the first machine (photo'd below) I replaced each set of like capacitors and then tested the player to see which was causing the issue. To remove the circuit board you have to desolder the two solenoid points (see red arrows below) and also remove the retaining screws.

The sequence was as follows;

1. I removed the easy capacitors first, these are near the motor and are through fixed - I have exact new parts for these. Result - Buzz remains, no change.
2. I then repaced the the two largested SMCs - the originals were 4v 220uf, the new ones are the same. Result - Buzz remains, no change.
3. I replaced the three small SMCs - the originals were 2v 100uf, the new ones 4v 100uf through fixed but I cut the legs to SM them. Result - the hum disappeared, music plays with good sound but about 25% the volume it should be.

A largely sucessful repair, but I woud love to know why the low volume? Could it be the 4v 100uf caps which fixed the problem - but what's the alternative as 2v are NLA?

The last photo shows the before and after caps replacement...

I did the same repair with the second machine, but it still buzzes as before.

 

Marian, who is a member here is the best place to get fine belts https://fixyouraudio.com/
I have bought a few off him.

There should be no problem in using 4V capacitors instead of two.
Have you fitted them all the right way round ?
It would be worth replacing the last two.

Other than that, if you have access to an oscilloscope try tracing along the signal path from the heads to the headphone socket.
You don't need a fancy one for audio work.

 

Thanks for the reply - I like 'fix your audio' but funnily enough the 310 / 327 / 510 have no belts listed - also very difficult to get a service manual for them as well!

I will replace the last two caps, shame it will be with 4v bigger caps.

I do have an oscilloscope but I'm not 100% surre how to use it, but I'm willing to learn.

Using wireless headphones the volume is fine as they have their own amp - sounds quality, speed and functionality are all spot on. You do have to pull the headphone jack out slightly to get stereo - with the jack fully pushed in you lose a channel. Likewise when pulled out slightly and you select 'metal' you lose a channel...

 

Success! It's fixed - I am so pleased! Often things are not as good as you remember them, but these Aiwa's really are, the sound, the quality of the machine - really fantastic.

Although I had it working pretty well, the lack of volume was a bit dis-satisfactory so I went back in to replace the last two caps - I swapped the 220uf 2v SMCs for larger sized 220uf 4v SMC's, but removed the plastic base to allow them to fit.

I also swapped over the mechanism from one of the machines where the play button had stopped working - it was in almost new condition as it had obviously been used up to the point that the solenoid (I assume) went wrong, but before the caps failed.

Looking at the other thread about the P50 restoration I notice that Aiwa used the same basic mechanism and circuitry for many of their mid-80s to mid-90s higher end models.

The only slight issue I now have is the auto reverse doesn't work (which it did), I think I've misaligned a lever or something so will have to sort this out – hopefully not a big deal.

Anyhow, these little machine are worth persevering with - a massive amount of work, money and time, but actually very rewarding to do.

Next project - get a second one working – new tread to follow!

 

Congratulations! You must get a Star from The Community for reviving such a beautiful baby!!!
AIWA’s are my favorite Walkmans but being a wimp I stay away from them because of those rechargeable batteries. I managed to figure how to rejuvenate Sony Discmans batteries, but those in AIWAs are beyond my skills
Do post some photos of your baby!!!

 

Thanks for the encouraging words!

Unfortunately it’s not quite over yet. After half an hours faultless listening yesterday, today I find ff/rw makes it play (but not ff/rw), stop doesn’t work (opening the case stops it), play does make it auto reverse but not play to begin with, sound is only out of the left channel. What has happened to cause all of this, and why no problem yesterday?

I will not let you beat me hs-xp310!

 

I think the loss of a channel is a capacitor playing up.

The bigger problem I have is that the machine constantly autoreverses - is this likely to be mechanical or electrical?

Is this because I swapped the circuit board into another machine?

 

Do you still need the 310 SM?
The belts for the 410 are the same.

 

Hi yes - I very much need the service manual - I have ordered one online but they say it'll take 5 days to find it?

 

Here you go:

 

I made significant progress with both machines this evening - I worked out why the play and stop buttons often don't work. Where the solenoid is soldered to the board on the rear is a small track link which enables the play and stop buttons to active the solenoid - corrosion / oxidisation can break the link meaning that the play and stop buttons not longer work. I tested all the solenoids on all four of my machines by connecting them to a battery and all work.

On one machine I damaged the contact and this lead me to make this finding when I soldered a wire in place to remake the link. So I cleaned the connection on the rear of this machine and it worked again...though only on one channel and after 5 minutes the sound fizzles out - but it's much better than it was!

So both machines are heading in the right direction but both fizzle out after 5 - 10 minutes - I have obviously duplicated a problem - the wrong type of capacitor perhaps?

 

HWTest - you have made my day - thank you! This will help me so much to track down some of the issues.

 

I'll be watching your progress closely because my two 410s and one 310 are waiting, I'm fighting the transport in my AIWA AD-S950 tape deck now ...