jim.hoggarth

I will try to remember to foolow up here. If not, give me a nudge. Jim

I am absolutely astonished that the unit I mentioned yesterday has just sold for 82.00 GBP, considering that it is faulty. I just hope the buyer does not contact me to have it repaired! To repeat, I am absolutely gob-smacked. Perhaps I ought to dig out all my non-working E10s and sell them off now while folk still have money to waste? Jim

Yes I would Rob. I will reply to your email soon - I am way behind with emails due to bad health (again!) and will get to yours eventually. Jim

I have just had a thought. If by chance it is just the OP or motors at fault, it's an easy job to swap the plastic sub-chassis over. I have lots in stock, some labelled as good workers. I have no immediate use for them, so it may be worth just sending one over to you. In my experience most players don't need much in the way of aligning anyway. And if it does the job, all well and good. Otherwise you are no worse off other than the postage cost from UK to AUS. If you want to discuss email me at jim.hoggarth@blueyonder.co.uk Jim

Sorry, bad news. I actually no longer take MZ-E10s in for repair. In the last few years I have bought many, and attempted to repair a number too. Apart from two good workers I have since sold on, every one has had the same basic fault. Here's the problem: The E10 has just five major parts, excluding the battery. Upper case, disc slot, motor/optical chassis, circuit board, and the lower casing. The motors and laser very rarely fail, at least in relation to the number of these units they sold originally. Unfortunately Sony decided it was sufficient to just screw the circuit board directly onto the lower casing, with no form of cushioning at all. If the unit is flexed, as it obviously will through 'normal' use (ie not superglued to a massive steel block), all that movement is transmitted to the circuit board. It has no option but to flex too, as it is securely fastened to the alloy casing. That's all fine for the actual circuit board which has a degree of flexibility, indeed even small components with just two or three leads will stand some movement. But there are a number of highly miniaturised integrated circuits on the board which are basically a (relatively) large slab of immobile plastic with *lots* of delicate connections. So inevitably the soldered joints start to crack (in two instances I have seen a major chip actually totally disconnected from the board and rattling around). This not a too major problem as some can be very delicately resoldered. But not those beneath the largest chip, which does all the processing, decoding, etc etc. This has so many connections to the outside world they will not physically fit on the outer edges of the IC, and must be underneath. In this case standard soldering is impossible. I am guessing an infra-red oven of the type used to manufacture the boards would be needed, after removing any components made of plastic which would melt of course. Consequently the E10 is as good as unrepairable. I admit, sometimes the problem may just be the remote control socket which has suffered broken joints, but usually also with the associated copper tracking being ripped. In this case I have tried using mod wire to patch up the circuitry, but found that the wires will not physically fit in the meagre space available, never mind trying to solder wires on to minute component solder lands. I know I am sounding negative, but you may be better getting rid now while there is still a market for non-working E10s. Take this one for example - do a search on ebay (any country) for item number 400452265048. As I write this has less than 24 hours to go, and may well get more than its current 54.00 GBP. And the seller openly admits that the unit gives read errors. I have seen a similar unit sell recently, again said to be faulty, which I seem to recall reached 80 GBP?? Absolutely ridiculous, to my thinking, as I know they are probably unrepairable. I have been caught this way myself! Hope I have not ruined your day. Jim

Hi macbob. It is highly unlikely to be the write head or its cable at fault. In my experience faults such as this are caused by the optical pickup assembly on Hi-MD recorders. And replacement is a very delicate job. The disc may or may not play back on another unit - it depends on the nature of the problem. But it is certainly worth trying before reformatting it. Jim

I have never had such a problem with the MDM-5A drive as used in the JB920. One of the links you include reads like advertising blurb to me, with no basis in fact. And I have never come across any reference to a redesign for the MDM-5A chassis or slot mechanism. Indeed, I actually regard this drive unit as the most reliable Sony ever made. It seems to me you just have a ;aser unit that is 'fading' and needs replacing. That would account for a 'weak' track on recording, or an inability to read that track back without so many errors that the error-recovery coding cannot reconstruct the signal. Jim

Can you confirm your faulty unit is the MZ-E10? Jim

I am pretty sure it's not a light - just a red button that looks like a 5mm red LED. EDIT: Yes, that's correct. I just rembered where I had one and took the display board apart to check. Just a button. Jim

The E25 is a dual-battery model, and will take gumstick batteries or AA rechargeables, so there's no need to buy expensive gumsticks as AA NiCD and NiMH can bought very cheap these days. And whilst on the subject of the E25 (and some other early 'E' models): PLEASE CHECK THE ADAPTER VOLTAGE !!!! If you insert a 3v adapter into the power socket of a player that is designed to use the 1.5v mains charger, and both use the same size socket for some stupid reason, you will DEFINITELY destroy the DC/DC converter chip on the main circuit board. I see lots of these units that are dead, where the owner has plugged in the 3v adpater they use for their more recent Sony gear. And these power converter chips can only be got from other Sony players that I am aware of. The full list is: MZ-E25, E30, E32, E33, E44, E45, E55, E75, E80, EP11. You have been warned! Jim

The format used to record tracks is incidental. As far as the hardware is concerned, the signal going to the write head is just a sequence of pulses. The material being recorded or the format has no bearing on the hardware apart from when reading back, as obviously less lossy formats need to be read more often. The whining noise could be caused by an off-centre or bad disc, and using a different disc will often get rid of this kind of noise. Usually this is a high-pitched whistle. Lower frequency noises are usually caused by the tracking and focus servos working overtime, so that the laser object lens oscillates at a near constant audio frequency. This is probably a sign that the laser is in need of a clean, or the laser unit or servo electronics on the main circuit board are on the way out. Another cause of noise is dirt in the optical carriage driving rack and gears. In the case of some models, noticably the MZ-N910, it is caused by the sled drive reduction gear actually jittering as it spins. A characteristic of this sort of noise is that it only screeches when the laser moves in one direction, either outbound away from the spindle motor or inbound toward 'home' position. In your case, the NH700 does not normally suffer from the latter. I would bet a good service and perhaps a part swap would sort it out - could be the spindle motor, sled motor or laser unit at fault, or even the main board - I would have to hear the noise and/or get it on the workbench to be sure. Jim

I can confirm I no longer have any working RH10 OLED display boards in stock. Just fit the last one to a machine here in Blighty. Getting hold of replacments is now an almost impossible task. And I reckon the RH1 is going to go the same way. I have already seen two RH1 display units where one out of the two display sections have failed totally or is very dim. Jim

A laser cleaning disc or even a swab with alcohol does not always do the trick. If the optics are 'open', as is usually the case on minidisc pickups, the tarnish which covers the objective lens will also adhere to the light bending prism and laser diode window. As these cannot easily be accessed, once bunged up with tar and nicotine the laser is just about useless. But if the optics are fully or even partially sealed, just cleaning the objective lens can work a treat. The answer, of course, is to not smoke in the first place. As an ex-smoker (13 years and counting) I can tell you I now hate opening up a unit from a smoker. In the worst of cases you can actually feel the sticky residue on the cases. Yuck! Jim

New batteries are available - I purchased one myself recently from a company in Germany. http://www.ebay.co.uk/itm/BATTERY-FOR-SHARP-AD-S30BT-S31BT-T50BT-T51BT-/360623523173?pt=UK_Camera_Batteries&hash=item53f6d64565 Jim

Ho hum! That day I was working on an MDS-DR1E, which has the same drive unit as the MDS-JA3ES. I got horribly confused. It is of course nothing like the drive in the original posters question! Jim

The KMK-260AAB refers to the complete drive unit, and it is not Sony. It probably uses the KMS-260x laser unit, but the rest I recognise but not as a unit used in Sony gear. It is probably for a Denon. I am sure it is not Goodmans or Grundig, perhaps it may be Pioneer or Sharp. I have to ferret about in the loft later today for a particular part. At the same time I will search through the decks I have up there. There is a distinct possibilty I have a complete boxed JA3ES that I stored many years ago but forgot I had. If I have, I will partially dismantle it to examine the overwrite head and compare with others. Hopefully I am not dreaming and one does really exist up there. I will let you know one way or the other shortly. Jim

From a technical viewpoint, they are somewhat similar but still different enough to notice. They both use the MDM-5x drive unit which got rid of the load/unload oscillations that the MDM-3 family suffered. I actually like this drive, as it is plastic enough to be light but with enough metal to be robust. The '530 has a slightly improved optical pickup then the '520 - from the KMS-260A to the 260B variant. I believe the only difference is the error rate figure. And somehow the overall power consumption is improved by a couple of watts (from 18W to 16W). It is not apparent from the circuitry how this has been done, probably changes in the ICs used. The major changes are the remote control, and the master chip (including the ATRAC encoder/decoder): the '520 is the CXD2654R and the '530 uses the CXD2656R, and the ADC/DAC. One obvious result is that the JE530 has the Type R DSP. And the digital-analogue conversion is much improved using an 'AK' brand chip rather than Sony's. I believe this gives more bit resolution here. So given the choice, always plump for the later model. I am sure Stephen will add to this, as he knows the firmware side better than I. I just fix 'em - he actually listens to them! Jim

Oops! Rare faux-pas from Stephen here. MO means Magneto-Optical, not Metal-Oxide. And the CD discs do have pits (and lands) - that is how CDs work, as Jimma points out. The laser is focussed on the track and is reflected back - the lands are very high brightness as they are like a mirror. The pits ensure that the reflection is exactly 180 degrees out of phase due to the extra distance travelled before returning - hence the reflected signal is low intensity, and that is how the data stream is read (very reliably, and much easier to read then the MO data. Jim

The reason is simple - you are erasing the disc, but not re-recording. More specifically you are erasing the TOC, or table of contents, when the edit is written back to disc. The laser does the erasing, the write head the recording. So if the head is bust, the laser just melts your data away... (past the Curie point if you want to be specific). The data is still on the disc, at least the bits you have not erased by overwriting. So if you replace the TOC on another deck (can't be done easily on a portable), you can get the original disc back albeit as one long track. Jim In my experience write heads do not fail electrically. They are damaged physically, as oroville is pointing out. Usually by ramming a disc in the wrong way, or some other mechanical tragedy. Incidentally, the JE320 is not a cut-down sibling of the JE330 as is often assumed. It has more in common with the MDS-JE510 as they share the same drive unit. As in the all-metal one which does the 'eject-shudder' so famous of the JE510. Jim

Simply the part number. There may be subtle differences, I couldn't say until seeing one and physically comparing. Usually it is not the head and arm, but the plastic back-piece - more specifically, the part which lifts the head away from the disc when in playback mode (the heads are of course designed to be in the loaded position, as you know). I have seen several designs across lots of units, whether Sony branded or otherwise (but using the Sony KMS-2xx optical pickup unit). It could indeed be that another head would fit, but I can't say as I have never seen this particular drive unit. And there's no way I will drop myself in it by saying otherwise. In my experience if parts are identical, so are the Sony part numbers. Otherwise there is a definite difference, however slight. It may just be the cable, which of course could be swapped over to 'make' an original replacement part. I just can't say 100%. Jim PS - been off line for several days, sorry for not replying sooner.

The write head on this unit is not the same part number as any I have in stock - it is shared between this and the JA20ES onyl I think. So I doubt any I have would actually fit, at least not without modification. The important thing to note is that the top-end decks have disc drawers more liek a CD unit, which must mean the write head is substantially different. Although it looks about the same on the exploded diagrams. Replacement of a head is easy. You really only need to unscrew the original damaged part and screw the replacement onto the optical pickup block. It is advised that a screw sealant is used. If you have none, nail varnish is a good alternative. Just a tiny amount is needed on the thread. Sorry I can't help with the part - I am a poor peasant engineer who cannot afford these posh up-market items! Jim

Using the 500mA charger rather than the 1A that comes with the unit, you can get away with it. I wouldn't try recording in Hi-MD mode with the AC-ES305 (AC-MZR55?) that came with the MZ-N1 though, especially if the internal battery is also flat. You may get record errors, which could ultimately lead to making a nice expensive 1GB disc into a coaster. But that does beg the question, why is it allowable to power the unit off the USB line when the theoretical maximum current down that is also 500mA? In fact I have come across USB sockets that purport to provide full spec power on the 5v USB line but fail miserably. Personally I never rely on USB outputs for power, always prefering separate supplies. Jim (must update by listening list at some point !!) V V V V V

I doubt the charging protection circuitry in the Li-Ion battery would even wake up, on the other hand - BANG!! :bomb:

Having taken a closer look at the RH10's service manual, it appears the chrging circuitry in this model is a lot more sophisticated than the N710. Indeed it has to be, as charging can be done from 3v power supply or 5v USB supply. The same suspect resistor does not exist. What is very surprising to me is that according to the schematic, the external AA battery is, literally, just strapped across the internal gumstick. That seems a bit odd, with one being 1.5v and the latter 1.2v, so maybe there is something in what both Sean and Stephen suggest - that inserting a good quality AA 'Duracell' will kick a recalcitrant gumstick into life. Another oddity - the SM gives the gumstick as the NH-14WM (black/orange). But I was sure Hi-MD units were only ever shipped with the NH-10WM (grey/orange)? One hour later - done a round of service manual checks and it seems the charging circuit I am describing only exists in the N510/520, N710/NF810 and N910 (interesting as I have seen an N910 having exact same problems). So I was jumping the gun to think the N710 tests I had been performing applied here. So yes - Sean's observations are true - probably. Jim

I'm not too sure about this. I have been giving the MZ-N710 charging problem a lot of thought recently, and come up with a possible chink of light. If you recall, we discussed N710's tending to dislike charging gumsticks. We had several thoughts, the most obvious being that the battery contacts *must* be clean and free of corrosion or tarnish. That doesn't solve all problems though. Then the idea was that leaving it in a charging cradle for a while helped, especially if connected to a high-current bench prower supply. Also there was the voltage settings too low, as in the difference between Malay/Japan factories. Each little thing seemed to cure some units, but not others. Plus there was the idea, as above, that boosting it with an AA add-on case would help. Recently I have been experimenting again, specifically with the N710, as there are some units that just will not cooperate (initially) even when several of these 'tricks' are performed. So I sat down with the circuit diagram and had a real good look. I now have a suspicion that all - or most - of these solutions may have been a sheer fluke, and the actual problem is the charge current detection circuitry. This idea came to me after a particularly bad example starting working fine after having the back case removed. Previously it would either not charge at all (nothing appeared on the screen), started charging and stopped again within seconds, or simply charged the battery to an early stop, perhaps just a third of the potential battery capacity. I believe it to be caused by the charge current detect resistor. This has to be a small value, otherwise it would drop too much voltage and consume a lot of power, turning it into heat. The resistor within the N710 is 0.022 ohms. Yes - just one fiftieth of an ohm, not much higher then the resistance in a short length of wire! I suspect that a bad joint, perhaps just a hairline crack in the soldering, is increasing the ohmic value and thus dropping a greater voltage than it should. The result could be that internal battery resistance is misread, or current miscalculated, or the final battery voltage detected too early. Now the resistor is found on the lower edge of the circuit board, where a lot of flexing is possibly going to occur due to power plugs being inserted/removed, being placed on a charging and stand and - possibly - when an add-on battery box is screwed on to the unit. To be honest, I have not proved this to my satisfaction yet. I am still waiting on finding units with the same problem, and going straight to this resistor and resoldering the pads. If this cures it instantly, for several machines consecutively, (and taking into account that some units may have other problems besides), I may be willing to claim success. But the jury is still out. Jim