Repairing a Aiwa XR-M500 micro HiFi, need help in stripping it down - Page 1
Forum section: electronics / repair

author: Specmaster
author_rank: Super Contributor
timestamp: November 10, 2018, 08:57:59 pm
content: I have this unit on my bench for repairs with the following issues, no tape activity at all and CD cannot play track 1 it struggles to track or even start on track 1. Track 2 it will play but sometimes will skip a bit from there on it is fine. Now I have come across before on other CD players and can fix it if I can get access to it. This is typically caused by dirt and dust on the gears and in particular the tracking gears.I have removed the back, top and sides of the case which provided easy access to the tape drive, Got this out and the problem with that is the 2 drive belts have become basically sticky goo and fell apart, this is horrible sticky stuff like tar (quite possibly some has fallen into the CD drive which is below. Drive belts I think I can overcome as there is a company that supplies drive belts for tape drives etc.Problem is I cannot see how to gain access to the CD drive which sits right on the bottom with the main amplifier board (looking at the unit from the rear) vertically on the right that on the right that plugs onto the control panel at the front. Plugged horizontally onto the amp board is the tuner, vertically at the rear is the power supply, on the left side, again vertically is the CD control board.I'll post some photos to further update this thread shortly to show the layout and the issues that I'm struggling with. I have removed the tuner and removed any screws that are holding down the heat sink, removed all ribbon cables and other ancillary leads that can get access to. Removed the volume knob and likewise all the screws that appear to be retaining the front panel to the chassis but cannot remove the front panel.Has anyone attempted this type of repair before or does anyone have any knowledge of this particular unit at all, if so then I'd love to hear your thoughts and ideas etc on how I can get access to the CD drive, please.Edit. I do have a copy of the service manual, but it makes zero mention of how to dismantle the thing, seems to make the assumption that everyone knows what to remove and in what order etcEDIT:Here are the photos to help jog memories etc.

author: commongrounder
author_rank: Frequent Contributor
timestamp: November 10, 2018, 09:54:07 pm
content: Many of these Sony/Aiwa/Panasonic mini-stereo units have a sub-chassis for the CD mechanism that is essentially the bottom of the main chassis. Remove both sides, top, and possibly the rear panel. Release the one or two ribbon cables that run from the main circuit board to the CD chassis, then remove the screws that hold the CD chassis to the front panel and other mounting points. You should be able to remove and then gain access to the actual CD transport. With luck, a cleaning will clear up the problem, but a weak laser is not uncommon. Good luck!

author: Specmaster
author_rank: Super Contributor
timestamp: November 11, 2018, 09:11:06 am
content: Quote from: commongrounder on November 10, 2018, 09:54:07 pmYes I agree that is how it ought to be but as you can see from the photos, the case has been removed and tape deck. However the PCB's are not cooperating. Tuner is removed, next is the amp board, that's the large one on the right with large heat sink. I can get the top plug / socket undone but it still seems to be connected at the bottom. It looks like the front cover needs come off but it won't move. All external screws and volume knob removed but I can't move it. There are plenty of screws holding the PCB to it inside but access to them is not possible till the amp board is out of the way.

author: commongrounder
author_rank: Frequent Contributor
timestamp: November 11, 2018, 05:31:01 pm
content: The additional pics help. Is it not possible to detach the bottom plate from the front panel? Maybe some hidden snap latches holding it in. If the bottom plate can angle down, even with power supply/amp attached, the CD chassis should be accessible. On virtually every one of these I’ve worked on, the access to the CD section has been through the bottom. You shouldn’t have to pull circuit boards. Also, can you see hooks from the CD chassis engaged in slots on the bottom plate? There has to be a way that doesn’t require extreme disassembly.

author: Specmaster
author_rank: Super Contributor
timestamp: November 11, 2018, 06:33:23 pm
content: Finally solved the riddle, there is well hidden plastic latch in the front that locks the bottom of the amp board so although it was unplugged at the top it was still being held by the latch. Amp board, CD control board have to be removed, then there is a plastic bridge that has to be removed and then you have access to the 4 screws holding cd drive in place.Once out I thought I saw the cause of the problem, a piece of the tape drive belt had dropped and dissolved into a sticky black mess and the laser ribbon cable was stuck in this. Cleaned it all up with Isopropanol and, checked the gear mechanism for any signs of dust etc that might cause problems with travel for the laser, none seen. Reassembled powered up and the problem is still there on tracks 1 and 2 on some discs. The further the laser travels out towards the outer edge of the discs it is perfectly OK.If I lay the unit on its side it works perfectly, as it does if I tilt the unit by approx 10 degrees to the left or right but upright, track 1 will attempt to play after a struggle but is unable to track correctly and track to I only have to touch the unit and it starts to skip parts of the track, and once on to tracks 3 and higher, problems?After dinner I extract it again and have another look, maybe lube the travel system at the track 1 location and see if that helps.

author: commongrounder
author_rank: Frequent Contributor
timestamp: November 11, 2018, 10:07:54 pm
content: Also, check the spindle motor bearing for excess play. Resulting disc wobble can cause skipping due to the disc surface moving out of the laser focus range.

author: Specmaster
author_rank: Super Contributor
timestamp: November 12, 2018, 08:27:22 am
content: Quote from: commongrounder on November 11, 2018, 10:07:54 pmSurely that would be more noticeable at the end of CD rather than the start at the centre?I think I have located a possible donor unit that has the same deck in it. The rest of the unit is vastly inferior so I don't mind gutting it for parts.

author: commongrounder
author_rank: Frequent Contributor
timestamp: November 12, 2018, 01:53:16 pm
content: A donor chassis would render moot this discussion, but wobble can be worse in spots other than the end because CDs track at Constant Linear Velocity, which means the speed varies as the playback progresses. There can be “resonant” RPMs that accentuate the wobble in certain portions of the disc. Where would depend on the condition of the motor bearing. Best of luck with your repair.

author: mnementh
author_rank: Super Contributor
timestamp: November 12, 2018, 05:22:31 pm
content: Oh, hey Spec - I must've missed where you said you'd started a thread on this unit.Here's a service manual if you don't have it:https://www.manualslib.com/download/970141/Aiwa-Xr-M500.htmlI'll move my other posts over here later; looking the manual over right now.Oh jeez... is this that goofy one where the control panel rolls around so you actually have different buttons depending on what you want to play? Wow... that's a blast from the past...mnemBBIAB...

author: mnementh
author_rank: Super Contributor
timestamp: November 12, 2018, 07:06:03 pm
content: Okay... looks like this model uses the sony KSS-213F/KSM2131FAM mechanism... there areclone models on AliEx for ~US$18-25but the genuine Sony part appears to be unobtanium.There are lots of the cousin KSS-213C/KMS213CM assembly, it appears both genuine Sony and clone (or clone mechanism with Sony laser pickup) on fleabay now.In some cases, these can be dropped in place of other revisions, others they won't work but can be robbed for wear parts or your head and/or motors transferred over. If you have to transfer spindle motor over to new mechanism, be very careful measuring old spindle platter height so you can get it just right. This is something I try to NOT due except as last resort; the platter can be hard to remove from the spindle motor without ruining it.Common headaches include: differing motor voltage, CW vs CCW rotation, PCB may need to be unsoldered from motors and swapped over.https://www.ebay.com/sch/i.html?_from=R40&_nkw=KSM213&_sop=15https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20181112103715&SearchText=kss213Fhttps://www.aliexpress.com/wholesale?catId=0&initiative_id=AS_20181112103819&SearchText=KSM2131FAMhttps://www.donberg.co.uk/search?query=KSM213*https://www.aliexpress.com/item/KSS-213F-Optical-Pickup-KSS213C-CD-Laser-Len-Lasereinheit-KSS213D-KSS-213D-For-AIWA-CXNSZ50K-NSX/32855649327.htmlThe real suck part is I could not find anywhere that had the bobbins with the assembly.And I know from experience that they are a complete charlie-foxtrot to find separately. Like I said, I suspect it is deliberate.If you need belts for your cassette player, this is not a bad deal:Assortment from 24-80mm; maybe you can find the equivalent on your side of the pond.Cheers,mnem*Back to the grind*

author: Specmaster
author_rank: Super Contributor
timestamp: November 12, 2018, 07:20:13 pm
content: @mnementh, Yes that is the one and I must say that with some decent speakers it sounds reasonable considering its not what I call proper hi-fi.Thanks for the link to the manual, which I already have and I'm sure I've already mentioned the manual in previous posts, maybe the coffee hadn't kicked in when you was reading the posts eh?.I now have the donor machine and have tested it out and it works OK and after I've had my curry, I'll be tearing it down and checking the CD and tape drives, but looking at the 2 manuals side by side they do appear to be identical, I attach exploded views of the drives in the M150.Although the pages are prefixed XRM100, it does in fact cover the 150 as well, cover attached shows the range the manual covers.Now, its nosh timeEDIT:It seems that the pages have come out as blanks so heres the linkhttps://www.electronica-pt.com/esquema/audio/aiwa-audio/aiwa-xr-m100.-xr-m150-31967/view,article/

author: Specmaster
author_rank: Super Contributor
timestamp: November 12, 2018, 07:37:40 pm
content: The first drive shown on this link is the one fitted I think, it has the fixings in the right location for shock bobbins and it has the shutter to cover the lens when no CD is in the drive.https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20181112103715&SearchText=kss213F

author: mnementh
author_rank: Super Contributor
timestamp: November 12, 2018, 08:15:55 pm
content: Sorry... I'm in the middle of some hardcore hoeing out of the house; stuff leaving by the carload. FINALLY. I'm a little distracted.Yup... some of the older Aiwa bookshelf units were pretty amazing; I have one Karaoke model unit my wife uses as a PA system in her school now that we've had for over 15 years. The speakers are BI-AMPED in that thing! Every few years I go through the CD and cassette decks to make sure they're functional, like it really matters... all she ever plays through it is her 180GB iPod for the music class.Just be mindful that is a Hekesaya clone assembly; while the laser assembly appears might be genuine Sony, the gears, motors etc are clone parts.mnemTote that barge... lift that Perego Gator quad-wheeler!

author: Specmaster
author_rank: Super Contributor
timestamp: November 12, 2018, 08:32:12 pm
content: Tear down of the XR-M150 complete loads of bits are identical at least at first glance, heat sinks, transformers, CD and tape deck really do appear to be same but with different lengths of ribbon cable obviously but this one has a way smaller amp board than the M500 does. It was extremely easy tear down, unlike its bigger brother, that was a real pig to do the first time, hence this thread, once you clock the hidden catch on the amp board and taken a brave pill (in the total absence of any guidance in the SMM), and removed the CD board in order to reach with, a bloody long cross point driver, the last 2 screws that retain the front panel to the thing. You then realise that the rotating control is not going to self destruct as it breaks into 2 parts, as I first thought it would, oh life would so much easier if the manuals up correctlyNow to tear down the M500 again and extract the drives and examine before beginning the transplants.

author: Specmaster
author_rank: Super Contributor
timestamp: November 12, 2018, 10:01:15 pm
content: Update:Cd drive swapped over, ribbon cables also swapped in order to connect to the same points, drawer front swapped to match the front panel, powered up and bingo performs flawlessly so that was money well spent on the donor stereo, now to reassemble the M500 upto the point of the tape drive and then I'm going to transplant the drive belts over and then hopefully that will be a wrap on this unit and will be restored to full operation once again.If it all works OK, the unit that I picked tonight for a just £10 will have been a bargain even if I just junk it in the bin, it will have yielded up a CD drive, Tape belts and a pair of useable speakers and spare tuner (FM/AM) as it is the same unit. Having said that I could just make it into a radio with a CD drive that plays from track 3 onwardsand if I order some belts, a working cassette deck.

author: mnementh
author_rank: Super Contributor
timestamp: November 12, 2018, 10:33:00 pm
content: Put it out for 5 clams in your next yard sale; somebody will buy it to plug an old phone into for streaming music as a garage beater. Or just donate it to the local thrift store and cultivate some good karma.mnemKarma: It's what's for dinner!

author: Specmaster
author_rank: Super Contributor
timestamp: November 12, 2018, 11:05:07 pm
content: Now thats a good idea, tape belts fitted and all is well, forward and reverse perfectly, just need to find a blank tape and see if it records OK.EDIT:Recording perfectly so this started out as a £20 punt, mainly because I was looking for some small speakers to sit behind the TV and connect upto a Teac CR-H240 CD/FM/AM/DAB receiver that will sit under the TV in the cabinet along with the cable box and wifi repeater so that SWMBO can play all her CD's. She keeps asking people to get them for her as Birthday and Christmas presents and then they never get opened because the hifi that I had was too big and so it had to goSo when I saw this unit on the bench, I was so impressed with its capabilities and looks that I decided it needed another chance of staying out of landfill but it had a CD and Tape issues. Now as a result, since last Friday, I have now sourced a nice small pair of Mission monitor speakers to behind the TV and 2 sets of decent Aiwa small speakers that can go with a further 2 Teac units, now I need at least another set for the M500 and maybe another set for M150 so it can be used by someone as a radio and mp3 speaker system by plugging their phone into the Aux input. I'm being overrun here with loads of TE and Audio gear....I need a bigger house.Tomorrow, I pick up another Aiwa unit, this time its a XR-MD510, same as the M500 but with a built in mini disc deck for playback and recording with another pair of original speakers and a remote control, all for another £20 and so it begins.Thanks to mnementh and commongrounder for their input as well, you've been a big help guys

author: mnementh
author_rank: Super Contributor
timestamp: November 13, 2018, 10:25:13 pm
content: Yeah... this is exactly how I wound up with 17 pairs of speakers (okay, a few of those pairs are a surround speaker set, but still) I just can't bear to part with. AFTER two rounds of triage and "Off to the Goodwill"...I STILL regret selling my Polk M3 Studio Monitors last move... even though I made $100 on the pair.mnemAnd don't even get me started on my subwoofers... *wibble*

author: Specmaster
author_rank: Super Contributor
timestamp: November 14, 2018, 07:58:24 am
content: Quote from: mnementh on November 13, 2018, 10:25:13 pmThey are unusual, not understanding why the are bent that way, have you got them upside down? The tweeter is the one normally that ought to be directional towards your ears for the stereo effect, lower frequencies are less directional.

author: mnementh
author_rank: Super Contributor
timestamp: November 14, 2018, 01:41:29 pm
content: Quote from: Specmaster on November 14, 2018, 07:58:24 amThat's just my pics from the auction. They are studio monitor speakers. They're made to be hung right on the ceiling and wall, or on the floor by the footlights facing up. Primarily intended for vocalists to be able to hear themselves over the instruments, they're really only good down to ~80Hz or so. But pair them up with a good subwoofer(s) and the presence is phenomenal; they are designed to be mounted on bracketry that allows you to place the soundstage exactly where you want it.Cheers,mnem"Bigger, faster, louder... all the good things in life." ~me

author: Specmaster
author_rank: Super Contributor
timestamp: November 14, 2018, 02:04:42 pm
content: Quote from: mnementh on November 14, 2018, 01:41:29 pmI see, they say a picture says a thousand words and yet they failed to tell me that lolNew Aiwa is OK apart disc error on the minidisc player so I expect that is going to be unobtainable

author: mnementh
author_rank: Super Contributor
timestamp: November 14, 2018, 02:34:13 pm
content: Yup. Very often just one pic is just enough information to be dangerous. This is pretty much how every "news cycle" operates anymore.From experience if you hang them from the wall like you're suggesting, the highs tend to bounce off the ceiling and backscatter destroys the imaging unless you hang them pretty low. If you hang them with the tweets low, you can put them a few inches down from the ceiling and no less than 1-2 feet from sidewalls and the image center stage is right about chest height, 8-10 feet from the back wall.I used to run mine Bi-amped with a pair of Boston Sub-Sat 6es in the bedroom; they were. And the wife liked them because they were iColored and matched.Sony MD mechanism, or TEAC?One of the popular ones had a 1mm square belt in the sled motor drive; much hilarity ensued when that turned to marshmallow.Most often, the recurring problem with any of them was the trapdoor mechanism not opening the door correctly and the head being unable to read sector zero to initialize.mnem*Back to the salt mines*

author: Specmaster
author_rank: Super Contributor
timestamp: November 14, 2018, 06:56:19 pm
content: If anyone else is having problems with the disassemble or anyone in the future wanting tear it down, I give this link to the missing information from the freely available service manual for this particular model and others within the family group. The model that this link refers to is the XR-MD510, basically the same model but with a minidisc deck incorporated as well and it also includes some test info / instructions for the CD deck as well, it is written in Japanese and English.https://elektrotanya.com/aiwa_xr-md510_511.pdf/download.htmlEdit.Just stumbled across this info, might useful, data sheet attached.

author: Specmaster
author_rank: Super Contributor
timestamp: November 15, 2018, 12:15:10 am
content: Quote from: mnementh on November 14, 2018, 02:34:13 pmI'm not sure, I did have it all stripped out and open but without the extender ribbons its impossible to run the system when it is stripped out to observe and measure and probe. I operated the MD by hand and the shutter was opening just fine. The only information I could find as to the makers name as the model number AZG-4A but google foh failed to turn up any useful info in that dept or indeed any selling any drives, I drew a blank on Aliex as well.

author: mnementh
author_rank: Super Contributor
timestamp: November 15, 2018, 01:38:58 am
content: Well of course you couldn't get the easy fix.mnem*Home alone widda kidzz*