imkidd57

I am repairing an MDS-W1 deck, which has quite a few problems including both AMS knobs which will not work properly; there is no spring to the 'push' action and no response from the W1 deck itself to any push/pull movement. One of the knobs won't show a change on the display to rotating it, but you can feel the clicks. Thanks to minidisc.org there is a service manual, and I took off the front panel of the W1 and located the left side panel board with the AMS unit on. The potentiometer-like unit is described in the manual as a 'rotary encoder', and was relatively easy to desolder the pins and lugs and remove it from the board. With the expected lack of a direct Sony spare part, I managed to disassemble the encoder to investigate and found it irrepairable, with some of the internal parts reduced to fragments which explains why it wasn't working! Looking on Farnell's website, I think I've found a possible replacement in terms of the various physical measurements, the right pin positions and is a push-on switch, but being completely new to rotary encoders I would like some advice on the electronic digital aspects of pulses per rotation (PPR) and detente (number of clicks felt when turning the spindle). When disassembled, the original unit had a disc with radial copper stripes, of which there were 20. Can I assume that these were responsible for the pulses, as very small copper pickups - one of which was still in place in the wreckage - would have contacted the stripes and could have generated the pulses. If so, then would this be a 20 PPR rotary encoder? The number of clicks felt on another working MDS-W1 deck that I have is definitely 20 for a whole rotation, so this is should be the detente. The possible replacement from Farnell is 24 PPR (and detente of 24), so would this make any difference to the performance and suitability? I can't see that an extra four clicks would screw things up as it doesn't seem to be doing anything other than change an observable number or menu option on the display. Any advice and opinions gratefully received!

Asivery also mentioned recently that they have got working the upload (PC -> MD) of the .aea files that have been downloaded (MD -> PC) from SP recordings. IIRC that was the only thing missing from the application; apparently soon to be released in a new version.

Another bump to this very useful topic... I had no idea that the R5ST had internal batteries, and this thread was a great alert to investigate! My internal batteries had also leaked and corroded the terminals a bit, but it seemed to be all dry and crusted without obvious spread to circuit boards and components. Was reluctant to use water, which could spread it further but scraping with fine screwdriver, finer cleaning with fibreglass brush whilst holding the unit upside down, seemed to do the trick. As for replacement batteries, I had a few old NiCad and NiMH size AA 1.2V which I had previously revived by charge/discharge. However they were mostly a bit too big in width or length to fit back in the unit; luckily there were 2 NiMH slightly smaller than the rest, which went in without too much force. Let's see what happens... I don't know how to ensure that any replacements ordered on-line would be the exact right size. BTW the power supply is supposed to be 9V 1.2A, not 6V. My R5ST came with an original charger which gives the spec (see picture). Also, before the recent event of swapping out the internal batteries, the unit went dead even with the original charger, and I thought it was toast. However I noticed the <reset> button on the underside of the case, and with the mains power connected, held it down for about 15s. Then the unit magically came back to life and was no trouble since then. No idea why it worked, but may be worth a try if anyone has a unit that seemingly fails.

Welcome to the forums. Are you sure the tracks were transferred from Sonicstage as SP? A legacy deck like the JB920 should play them even though they aren't true SP. Can you check...maybe they were encoded as LP2 or LP4 which it wont play.

As a point of accuracy, most legacy recorders will apply a time-stamp to an MD recording, which will be written to sector 2 in the TOC information. With some decks, this information is accessible via the 'Retry Cause Display Mode'. The minidisc.org archives are a valuable source for this [1, 2]. It' a slightly precarious procedure as you have to pretend to record on a disc, then put the machine into a form of service mode which allows the time-stamp to be displayed for each track by rotating the AMS knob. The process can be exited without actually recording on the minidisc's TOC. *Edit* - Actually after trying out on a JB920, it seems this info can be retrieved from the disc without the process of intending to record. Insert disc into the deck, then when the TOC information appears, press the <stop> button for 10-15 seconds and the display changes. Rotate the AMS knob to get time-stamp info for each track in the format YYMMDD. The examples below show tracks on MDs recorded on: 2003-04-17 (17th April 2003) 2006-09-03 (3rd Sept 2006) Small extra track recorded today (5th Jan 2021) Unfortunately for the OP, I don't think this is possible for portables; it's not mentioned in the service manual for the MZ-N505. Finally, of course the time-stamp will only be accurate if the original recorder had its clock set correctly. 1. How to put the deck unit into 'Super-Undo mode' (Retry Cause Display Mode) -> http://www.minidisc.org/super_undo.html 2. How to display the info (e.g. on an MDS-JE520); second table, top panel -> http://minidisc.org/retry_cause_display_mode.html

Thanks NGY... the width of the shell is 23mm so ordered some 29mm and 32mm diameter material that’s due to arrive in 4-5 days. Film thickness 0.1mm

Thanks NGY - that is a great suggestion. In practice, the critical tolerance for fitting into the MD compartment is the thickness of the LiPo component (the 'front-to-back depth' of the one on your image). It's definitely worth a try though... could you provide a link to the eb@y seller's items?

OK so I made two ;-) Was pretty straightforward from the instructions given on the original site. It's a very well-designed shell for the parts, and my earlier doubts about the battery being loose in the frame were unfounded as I didn't read properly: it is held in place with glue between its 'wings' and the frame. A few minor comments: The areas on a new print that catch inside the MZ-NH1 casing are the '+' and '-' characters, which were printed raised a bit too high. Easily reduced with careful sandpapering. The new LiPo battery's original orange sellotape, that covers the small charge regulator PCB, presents a raised hard edge to the MD battery slot as you slide it in. To fix this I carefully removed the orange stuff and replaced it with Scotch Magic tape, the edges of which were tucked below the height of the main battery and sealed with superglue. A better solution may be to embed the PCB in UV-setting epoxy, but this works well for now and the battery is protected inside the MD case. I charged the new assembly outside the MZ-NH1, just in case something had gone wrong with the circuitry, but it proceeded fine. Currently got two MD units soak-testing with continuous play, but 2 SP MDs into the test there is still full charge indicated on the displays. Now all that's needed is a case to hold a few of these...

How did you get on, Rusty? I printed a shell on a Prusa i3 MK3s+ in PLA, and although a bit rough and ready, it fits inside an MZ-NH1 quite well. A couple of areas needed a touch of sandpaper to stop them catching. Will try soldering the contacts and attaching a LiPo battery in the next couple of days.

FYI... I noticed a post by someone who created a 3D-printed shell for the new LiPo battery type, thus disposing of the need for the original LIP-4WM case with its extra thickness. The shell is printed on an Ultimaker, which is a fairly top-end machine, but some members may have access or could verify the print accuracy on a different unit (the .stl file can be downloaded from that page). It could also be useful to verify whether the new arrangement is a frictionless fit in Sony portables other than the RH1 which use the LIP-4WM, such as the NH1. https://www.hallaminventions.com/projects/minidisc-obsession The only slight drawback I can see is that the new battery is loose within its new shell, and would fall out unless supported when removed. So would need a case to carry around any spares.

OK can you be a bit more specific with your trials; it sounds like you have the outer covers off, but let's not assume. Did you use a charged and verified AA battery, or a 3V power supply? Pressed <Play> button with either blank or recorded disc? Does anything appear on the display, with or without a disc? Which electrical tap points are you measuring at, and what voltages are you expecting to see?

Another confirmed plus for this method; and one suggested slight modification. There seems to be a couple of layers of the orange tape holding the replacement battery's regulation circuit in place, which increases the thickness of the whole assembly. It's possible to take the outermost piece of sticky orange tape off, and 'unroll' the circuit away from the battery itself, reducing the thickness for eventual easier insertion into the MD player. There's still one layer of orange tape remaining to protect the little circuit board. I set the half-assembled new battery to charge in an external charger, which initially metered it at 57%, then rapidly got to the 90% mark and added around 107 mAh in 41 min before declaring it 100% full. Added the new battery assembly to an MD-NH1, and it signalled on the MD's display also as full. Then added the NH1 to the original charging station (with original Sony power supply); the charging light came on and MD displayed it as full with '00' min charging, and switched off as expected. I'll discharge it fully in the player and see what happens... but it looks good even with both protection circuits in place.

Legacy MD and MDLP, yes... Though AFAIK the MZ-RH1 (M200) method would not work for NetMD files, whereas MDTE does.

IIRC, it was included with SS 2.3.

There's a Sharp MD-MT2x0 on the top line, second from right.