kgallen

Yep. Extraction and reinsertion a couple of times will cause the contacts in the PCB socket to scrape the fingers on the FFC ribbon enough to cut through any tarnish and reestablish a connection. The FFC fingers are tin plated so relatively soft.

Guys this is fantastic stuff. I’m learning too! Keep up the great work and voyage of discovery! @NGY you are a gem beyond words. However for now the lid stays on my 530 as it’s working beautifully :-D Maybe I do some of these measurements on one of my 4xx decks...

Higher the number the more current is required to drive the laser to achieve the required light output. This is not a good thing. The higher current will likely result in more heating which is what degrades the lasers faster. However there is manufacturing spread in characteristics (as with any manufactured object). This means some laser diodes will need more drive current from new. Similarly some will require less. However as the manufacturing process will be tightly controlled the current spreads seen across laser diodes (at new) should be relatively small. Needing to increase the drive current as the laser ages is a downward slope to an expired laser.

Ah right I see... Just looked at the schematics. So there is already a 1 ohm resistor in the circuit, R169 (1 ohm 1%) that is between the +3V terminal and Iop terminal of the jig board. So yes, Iop (in mA) is equal to the DVM voltage reading (in mV). Carry on Sergeant!!

I'm not really comprehending these measurements :-( So you're measuring Iop using a digital voltmeter attached to your jig board? The DVM is on a voltage mode (not on a current mode). It's not clear to me from the SM how the DVM voltage reading relates to the actual Iop current. Page 37 does say the Iop in milli-amps is equal to the DVM voltage reading in milli-volts when measuring across 1 ohm. Well you're not going to put a 1 ohm load across the Iop terminals, that's a recipe for blowing up the driver chip. Maybe NGY knows how the setup works...

Its unlikely you need to replace them. Generally the exposed fingers at the end gather some tarnish/oxidation. All that is required is to pull the ribbon from the socket both at the MD drive end and the main PCB end and reinsert. Maybe twice. They aren’t desperately fragile but you need to keep them square in and out of the sockets and avoid putting a crease in them. Actually I found they are pretty much a standard electronics item off the shelf. I have a thread on here on just this topic (I’ll add when on a proper computer). They are 1.00mm FFC cables. You need the right length/width/number of cores and Forward/Reverse contacts (all Sony MD I’ve looked at needed Forward). On my thread I haven’t documented the 520 requirements as I haven’t ever had the lid off mine :-) Kevin ETA: Here is the FFC cable thread: (23/Oct/2020 I've updated the eBay UK links):

Oh dear. I wonder if I should replay my tired old record again that all educated and sensible people here are sick of me wheeling out. Maybe we need to check your ribbon cables for oxidation... :-D

Laser life and mechanical damage probably the only ones in practice. NGY will know better but unless you're into thousands of hours of laser use, particularly in record mode, then unless your machine has been abused then I'm not sure how many true laser failures are actually seen. We blame the laser a lot, mostly unjustly from what I've seen. When my newly acquired 530 gave C13's I looked to the laser for months. It wasn't, it was the ribbon cables (but everyone here is bored of that story, sorry [*]). Sure, audio performance can deteriorate when electrolytic caps dry out and if you're unlucky similar in the power supply section can result in noisy power supplies which can unsettle the digital logic. But we're talking Sony Japan here and they don't build their machines with junk components. My 520 is from 98/99 and is like new. Did you ever read the odo counters in your 520s? (Need to enter Service Mode - warnings per NGY from earlier in the thread). Kevin [*] It's where it all started for me on this forum

This seems too perverse to be true (note: I'm not disbelieving your analysis!). There must be some bizarre explanation! Whilst I've had similar with my Tascam MD-CD1 [*] (not actually the new track issue though), I've never had this with any of my Sony decks, not least my beloved 520. Let us think a while... [*] This deck has more firmware bugs than you can shake a stick at. Admittedly many are related to titling.

On the skips issue via TOSLINK I would also be interested in your answers to: - Have you tried a number of different CDs - Do you notice any difference in the skip issue between early tracks on the CD (inner radii) and later tracks on the CD (outer radii). - (I've read the thread and I think this is already in the pipeline) Is there any chance we can do an MD to MD TOSLINK copy - make an analogue CD recording on the "best" MD machine to get a first gen disc then TOSLINK that across to the second MD deck. I'd like to factor out an issue with the CD machine. - Another random idea is to test and be consistent with which way round the TOSLINK cable is used. Mark one end with some insulation tape. Try one way round then the other (in terms of which end is in the CD and which in the MD). Note if this makes any difference to skips or not. TOSLINK cables are not the most high-spec products and it's possible one end or the other doesn't mate so well with the connector in the CD or MD decks. This could cause significant transfer attenuation or light scatter which the receiver might not be able to handle. The receiver is trying to recover a clock signal as well as data from the optical stream. Jitter due to marginal receive power (light intensity) or multi-path effects can blur the interpretation at the receive end. This can cause the receiver to "slip" a bit of the data. Maybe I'm getting too deep here...! - Maybe I've missed it - do we know the make/model of the CD player? NGY - it's a bit of a long shot but I'm musing about bit slips on the digital transfer from the CD. Possible the CD XOSC is drifting out of spec? Just a wildas* thought out of the blue.

On the 520 (like the one in front of me now), if the unit is turned on, then moving the input selector switch between the three settings should result in an appropriate input message on the display: Optical In, Coaxial In, Analog In. Moving that switch carefully between the options a few times should help clean the contacts. Sorry for the lack of input from me, NGY's comments are far superior to any from me, but I will chip in if I have any thoughts to add, I am following! Kevin

Looks good! That's all you need! I must make one too some day...!

Can you play a disc recorded on another machine in the 470? Can you record to this machine (from say a CD player)? Will that then play back on this or another machine? Try SP and LP2 modes. Have you tried more than one disc? The symptoms you report usually occur when trying to play an MDLP track/disc on an SP-only machine but this isn’t the case here with the 470.

I can’t add to perfection! :-D The only thing I can reiterate is ESD precautions for both the laser and PCBs. When handling an unmourned OP it is paramount that the ESD link on the laser is bridged and removed in accordance with the Service Manual. Also when replacing such, the SM does detail the procedure and subsequent calibration. Test equipment in absentia, NGY has documented the pragmatic steps.

I usually use Sony minidisc blanks. But I’ve recently opened for use a couple of JVCs I’ve had in stock. I think they are quite attractive looking (in a minidisc kind of way you do understand!). I think they look better in real life than in this photo:

I found only one seller of the Sanwa LP1 in the EU in the Republic of Ireland. Rest were outside of EU so VAT and import duty would have been costly. The sale nearly went bad as they ended up not shipping the unit they had as they said it was a demo model and not fit for sale. They offered to order another from Japan for the original price but I had to wait about 4 months for it. Fortunately the seller came good in the end but I was nervous! It was the best part of 200GBP/Euro.

Yes my 530 is now perfect!

Yes, left and right << >> (might need to be in the Service menu). But the OWH will move with the OP rather than separately so this won’t gain you clearer access to the laser.

The Sanwa LP1 fits and works fine. I was able to check and set my MDS-JE530. Although it turns out the laser wasn’t the problem just oxidised ribbon cables!

I ended up buying the LP1 after spending over 100GBP on a good quality second hand Ophir LPM but the head just didn’t fit...

If this is for an MD machine, getting that head near the laser will be a real challenge. I’ve made the same mistake myself...

DIN UNLOCK only refers to the digital inputs - TOSLINK (optical) or coax. Recording using phono analogue inputs with no source will just give you recorded quietness. Note however that a single RCA/phono plug is used for coax digital - but of course using the single orange-ringed digital port rather than one of the red/black ringed analogue ports! Can you clarify? DIN UNLOCK means the deck can't 'lock' onto the data stream seen on a digital input. The deck is looking for a very specific format of data called S/PDIF which is a protocol to carry digital music data from one machine to another. In the case of CD/MD this would be two channels of uncompressed audio data. That two MD decks give you the same DIN UNLOCK message suggests, much as the original thread, that the source device is either not sending anything, sending stuff in a format that can't be understood by the MD deck or there is some interconnect issue - broken cable, incorrect interconnection or incorrect input selection. If the CD is connected to the MD via 2x RCA/phono then this is an analogue transfer and the MD input selector switch should be set as such. It is then impossible to get DIN UNLOCK - such a message makes no sense for an analogue input and suggests the MD input selector is in the wrong position. First thing is to go back to your TOSLINK cable, plugged into the CD output. Ensure you can see a red spot in the end you are about to plug into the MD deck. Then ensure you plug this into an optical INPUT on your MD deck. Your MD deck might have optical in and out, and the connector is the same, so check. Then ensure you configure the MD to look at the input you've used. Again your MD deck might have multiple digital inputs, e.g OPT1, OPT2, COAX, so make sure you select the correct one. For TOSLINK this would be OPT1 or OPT2. If you've connected with an RCA/phono coax cable in the orange-ringed ports then of course COAX is the appropriate selection. As you now have two MD decks, you could try linking those with your TOSLINK cable and see if you can record from one to the other. You could try this both ways round. This allows you to confirm the MD decks are ok in this respect, that you know how to set the input source and that your TOSLINK cable works. Combinations of this should allow you to isolate if the problem is with any of these pieces of kit. When experimenting, change one thing at a time and write down which combinations work and which don't. And let us know here what models of CD and MD machines you're using then we can be more specific on machine settings. Kevin

if you’re interested in the software side of things have you seen this recent thread?

From what I can discern from the Service Manual, one of them is the "main" one, with support for vari-speed and the other (or maybe the two together) is to support the 4x high-speed dubbing function. The DSP is the CXD2536 and is ATRAC1 v3.5 according to the minidisc.org page for this unit. Enjoy - certainly plenty of toys to play with on that deck!

Another "random" picture on SCMS copy bit values, this time from the Sony MDS-B5 Service Manual (click thumbnail):