Sanyo M9998 (LU) Restoration and Bluetoothing

[H3NK3L]

Been a hell of a nigthtmare, especially the rebelting part...
but finally succeeded to restore and add bluetooth to this non AUX-in device.

Step 1 :
removing the back cover, taking care not to forget to photograph every and all cable that needs to be detached before detaching it (there are a lot of those !),
Step 2 :
removing the black frame, held by different sorts of screws, it holds the tuner/deck/... be careful to photograph each and every screw and cable holder (black thing), because they are there for a reason... and to remove the microphone cable and plug and the 3 pins for the amss indicator leds - pink blue white on the bottom , and a a 5 pin plug that s on the bottom right hand side (and photogaph everything before removing). Dont forget to pull up the power and dial light button and turn them to keep them up !
Step 3 : rebelting..........a living nightmare...
On the backside : remove the 2 screws that hold the tape deck switches (white knobs visible), remove the back pcb (with a lot of flat cables and a few pins - again you ll have to undo some cable holders so be mindful to photograph ANYTHING you undo before undoing it and to photograph where cables pass - they are a very tight fit.
Uncut some cable holders so you flip the pcb 45 degrees and more to access the back of the tapedeck
Remove 3 screws holding a plate to get access to the belts.

Step 3 bis : clean any black detoriated sticky gelified belt residue (in my case it was allover the place) with alcohol

Step 4 : put in new belts (I use a "manicure" set, it has some accessories that help to hold belts in place and help tu pull them over the axes

Step 5 : reverse the operation, dont forget to re-attach any cables that were previously attached so they dont get in the way of the mechanisme and cant touch any belts or parts of the deck

Step 6 : while at it, I removed the front panel (first remove the 2 screws that hold the AMSS led pcb, to give it thourough clean

IMPORTANT : DO NOT press REW for some reason it blocks when everything isnt in place, can lead to breaking the REW button lever , same for the other buttons, so when the deck is out and nothing is powered on : when you feel resistance on a deck button : do not insist.

Step 7 : while at it, I replaced the lightbulb (that was still working but was permanently on) with 2 green leds (and their appropriate resistors), and slipped 2 3mm leds iinto the space between the Stereo/power/dolby leds to light the VU-meters. and added a button to permanently light the dial. I used a simple on/off button. The dial light cable is a red + white cable that is "stuck" right above where the tuner dial wire goes. I left that in place and took the blue wire (With a pin on the tuner pcb where it plugs into), that goes from tuner pcb to power switch (from where it goes to the dial light switch), thus putting the button in "paraellel" with the original dial light /battery check button. This way the original button stil works, and lights up the dial light and indicates battery level , the button I added only lights up the dial light (without battery check being activated).

Step 8 with all being back in place, after putting back all screws, re-attaching all cables,... and putting back frontplate and the all the other parts... I only needed the back cover to install a bluetooth module and its power adapter in it. I removed the pcb for phono / din / ... (this is the LU version so it has din and not AUX ), found the "line in" on the din and used to to solder the bluetooth line out to it. The DIN connector (on the internal pcb) had 2 copper contactors that permanently connect and are disconnected when a din plug is plugged in. In order to be able to record to tape and since I m not using a DIN plug plugged in but only its connections on the pcb, I put a slice of elctricians tape on the larger one of the connectors so they dont make contact).

Step 9 : Prepping bluetooth module : I use a basic bluetooth 5.0 usb bluetooth module with only a "status / answer call / on off" mulitonction button on it. I only use its pcb and not the entire black box thing it comes in. It has status micro leds to wihich i soldered new leds in parallelm, and then i burn through and remove the original microleds, thus giving me 2 leds, 1 for status and 1 for battery charging (module comes with an internal rechargeable battery). Parellel wired the only multifonvtion button so i can wire a momentaneous external button instead.

Step 10 : bluetooth power : I parelled a basic 220v to usb adaptor to the 220v power inlet (In my experience this avoids interference), opened a bluetooth cable and cut the +5v cable, which I have pass through an on/off (12V 2A) button to have a power on/off button for charging bluetooth battery and or have it run on ac power instead of its internal battery.

Step 11 : drilling holes....to put my buttons and leds. Since I use 12mm buttons and 3mm leds, I use a wood dril of 12mm and 4mm (I like to put in led holders, so need the extra mm), in my experience these allow to drill quite accurately and mildly withouth melting of cracking the plastic, and since they have a "pin" in the center they allow accuracy. I tape both sides before drilling though, makes for a nice and clean drillhole.

Step 12 : Put it all in place : soldered wires to the buttons and leds before fixing them in place, addes some hotglue on the backside so nothing can move afterwards. Put some rubber doublesided tape on the small battery (bluetooth) and stuck it to the back cover (minding it has airflow), and aluminum taped it for heat dissipation, glued the bluetooth module to a 2 mm rubber pad and then to the back cover, plug everything in (usb / jack for audio that was soldered priorly to the DIN IN and DIN GND).

Step 13 : guide all cables, plug everything into the back cover (this is where the photos comme in handy), re-attach the back cover, try everything out and here s the result :

 

[goodman]

Congratulations on the tremendous work you have done restoring and modernizing this box.
I also watched the video.

 

[H3NK3L]

Thank you very much ! (I m not good at videos lol)
(found your channel a while back )

 

[Tinman]

I think every Aiwa 950 (2) and 955 (2) I've owned had the cassette belt goo in it.
I bought my current 950 from a guy in England and didn't realize until after I bought it that it had the DIN instead of RCA connectors.
I found the L, R and ground on the DIN board and wired those to a phono attenuator then drilled two holes for RCA jacks and wired it to those.
If I knew then what I know now, I would've just done a bluetooth connection to the attenuator instead of installing the RCA jacks.
Cell phone makers are slowly doing away with the 3.5mm jacks so adding bluetooth is not only a convenience but becoming more of a necessity to connecting to these old boxes.

Nice clean work on this 9998 (I like the labeling).

 

[H3NK3L]

I think every Aiwa 950 (2) and 955 (2) I've owned had the cassette belt goo in it.
I bought my current 950 from a guy in England and didn't realize until after I bought it that it had the DIN instead of RCA connectors.
I found the L, R and ground on the DIN board and wired those to a phono attenuator then drilled two holes for RCA jacks and wired it to those.
If I knew then what I know now, I would've just done a bluetooth connection to the attenuator instead of installing the RCA jacks.
Cell phone makers are slowly doing away with the 3.5mm jacks so adding bluetooth is not only a convenience but becoming more of a necessity to connecting to these old boxes.

Nice clean work on this 9998 (I like the labeling).

Thanks
I like labelling so it looks a bit more coherent
Yes, goo is always a mess to get rid of, but I must admit that on the M9998...with its total lack of ease of access...if there is a worldshortage in long, short, twisted,... cotton swabs and isopropanol, that will be on me lol. Dont know about AIWA, my main experiences are with JVC 1 piecers, Sony, philips, panasonic, crown, which are usually great and easy to access. I hope AIWA isnt like SANYO for that !

I understand you, my first go-to (years back) was trying to turn DIN into RCA IN as well, until I came to the conclusion that most people actually just use it for bluetooth, and it s just as much, if not less, work to just get bluetooth in there from the start and not have the hastle of putting in RCA. Side-advantage : when I sell them, 99pct of buyers dont even have DIN so they re not even going to use it, and I often get asked if I can ship a DIN to rca or DIN to jack cable with the device so they can use it for their bluetooth adaptor, hence why not bluetooth it from the start, no externals needed. PHONO though seems to make a comeback. The days of Minidisc players, CD-players, external tape deck, reel to reel deck,... seem to be behind us. Anyways for practical reasons I therefore prefer using DIN for bluetooth and not touching PHONO , chances PHONO are used being way higher than having double input on DIN.

PS : DIN are odd birds.... I usually look at the service manual first...they very often, if not always, expect LINE IN levels ...which makes things a bit easier , often suffises to find the L R GND on the DIN pcb and just solder your bluetooth output onto those. Backdraws with DIN : often there is a pin that gets pushed when the DIN plug gets pushed in, and that releases a contact (like a permanent ON switch that goes OFF when DIN is plugged in) - most of the time they require REC to be pushed in. Other major backdraw : DIN often seems to supercede any other input, meaning when DIN gets input no matter what input is selected, you get what you put into DIN (except if you need tu press REC). Meaning on some devices : when bluetooth is on DIN, you HAVE TO make sure it can be switched of easely otherwise it will run even when set tu tape radio or phono. DIN is sometimes just getting to the amp through REC, sometimes it gets directly into AMP,... HEnce : DIN are odd birds / service manuals are treasures. I hope some day people selling these will understand European versions with DIN are not the same as the "normal" versions, and stop selling them after having messed with them to try and turn them into devices with LINE IN. Only this year I came accross 2 devices that had been messed with, with bridging the solderpoints of the rec bar, replaced resistors with off the scale values,... so I ve become quite careful when it comes to buying DIN versions now.

But then again I dont like touching original pcbs and even less modifying them, but thats just me lol. Side advantage of adding a seperate bluetooth ac to usb adaptor, and adding a bluetooth module seperately, only connecting the LR GND wires to the original pcb instead of going through a plug : if bluetooth evolves into something different... all I have to do is unplug (i keep the usb plugs and rca or jack plugs on the module and use a cable i solder to the audio in) the bluetooth module, take it out and put in the new one, plug in usb and audio and job done. Did my first ones back when we had bluetooth 3.0... upgraded some to 5.0 that way. Most of the job is taking off the back cover.

What do you mean by attenuator ? (reverse RIAA (LINE IN to PHONO) ?)
As far as my experience goes, a basic attenuator that doesnt modify the signal and just lowers the level, when put to phono gave very distorted sound. Reverse RIAA didnt, but gave lower signal.

 

[Tinman]

I'm not an expert and only used one the one time.
It basically takes out the garbled sound when connecting a line in into a phono connection.
As far as the Aiwas are concerned, they're not the easiest boxes to work on.
They don't have many plugs so you either have to unsolder or cut wires to gain access to certain parts.
Here's a thread of mine from a few years ago 955.
Once serviced, the TPR-950 and 955 are one of my favorite boxes for sound quality.
I'd definitely recommend picking one up if you can find one at a decent price, you won't be disappointed.

 

[H3NK3L]

Hello Tinman, I ll put Aiwai TPR on my " I wonnit" list then!

From what I gather AIWA seems to have had the same philosophy SANYO had, put everything in the center of the box, even if that means putting pcb over pcb and keep all space behind the speakers free)

(the insides of this Sanyo, some pictures I kept in case I go full masochist and restore another one of these - also a picture of the "kit" to light dial lights, vu meters, bluetooth it, button it).

 

[SGrant]

If you want to add Bluetooth a less elegant way, you can buy Bluetooth transmitters and receivers, such as on eBay, and arrange cables to plug them into the box's input or output terminals. But these adaptors would have to be recharged after a few hours use.

 

[H3NK3L]

thats why I prefer internalising them - that takes away the hassle of recharging and of carrying them around when its used nomadically. Often add a ground loop filter though, since I use AC to usb power to power up the bluetooth module...and I m European so I most often have to deal with DIN or PHONO... which in my experience are very prone to ground loop issues even with bluetooth receiver not installed inside but used wired to one of its entries.