M1JWR

Havent used the 980 for a while, no sound out of left analogue outputs, we all know whats wrong there, cracked joints, i used qed cables on it, they are a tight fit i know, been on and off a couple of times over the last 12-15 years, so its board out and reflow, cured of that now, the interesting little fact on this is that the main board clearly says mds je780 on the underside, ahh well, sony cost cutting !! so the 980 is basically a 780 with 940 chassis, front panel etc its a cross breed, we were conned !!!! update on 940, all spotty dog, i'll keep this one qed cables retired to the bin.

wonder if kevin had pressed the trigger on that cheap 920 a couple of days ago on for 40 quid with best offer needed work to drive unit, it had a remote aswell which was for a 480/980 maybe offered 30 or less, for educational experimental purposes of course !!!!

all i ever did in the past was have a bookmark on the firefox or whatever from ebay "sony mds" or sony mds-jb940 if you prefer, and every few days have a look see what crops up, looked in past listings and somebody bought a spares or repair one for 47 quid a week or 3 back, so they do crop up, but yes usually over 200 quid for a full working one, me and bear boy are waiting with bated breath on when you increase your vast collection, and i am sure you will have a deck with an mdm7a that you are willing to sacrifice if in the rare situation that somebody has been inside and knackered it, that does happen, owh is first to die, 930's are worth a bash aswell, i got one about 4 years ago, seller said no sound output,, figured he was using mdlp discs and was correct, exellent nick and nowt wrong with it 35 quid, 980's will go over a ton spares or repair, and what i call a sleeper, the 920, exellent quality machine, not big money, and if spares or repair a lot less and a 330/520 drive goes stright in. me, i am still whittling down my once vast collection of 440 and 470's

went for a ratch found the ex 470 power board and the s50 board, there are subtle differences, transformer is identical almost off s50 and the 470 one is a tad bigger, more unused points on secondary side, only differences with s50 one is that two of the part numbers are opposite way round and the windings are covered in lacquer or whatever and 940 one is wrapped with red tape the relay on the 470 board is identical to that of the 940, s50 one different make but would say the same, checked those diodes one way on all reads around 190 and the other is very high 1600 ++ replaced the transformer with one out of s50 and for good measure replaced the relay itself as further checks on both transformers were the same, primary side no contact between pins, no contact between pins from primary to secondary side, but there was contact between the two pins on secondary side, which was confusing because i knew the s50 one worked and because of that i think its the relay itself that was shot. youve probably gussed by now its all up and running, will keep an eye on that transformer for a while to see if the lacquer stuff bubbles up with heat, seen that with stressed parts in radios years ago. thanks kevin, ive learned a bit about transformers, because i knew little about those, and now others with the same problem with 940's etc will be rushing out and paying top dollar for s50's, now where did i put the other one !!!

my bad memory there is no continuity between pins 1,2,3,4 there is continuity between 6 and 8 my mistake sorry kevin so from that we can deduce its gone to another planet these others i have i think are same fitment, mds s50 one looks identical different part number and no red tape will be back if ive found others 3 years ago i bought a mdm7a off a guy ex 470 he also sent me the main board(now robbed) and a broken power board and i bought a 520 that was smashed for its drive unit and broke it for spares, thats the one you ended up with parts, ill go and have a ratch for those, the s50 one is handy, i know where that is and i know its ok. can only but try

yes there is no continuity between any pin in the transformer, will get to the diodes later originally when i did electronics so to speak it was with radios, cb's years ago 99% of them used a seperate power supply, so therefore little knowledge about them, all i ever knew was that they dropped the 240v to say 30v for example and then on to the regulators which dropped it further say 5v for the circuits that need that, on an now old cb the 240 came in via a protection diode and ash filter then to the vol/on/off pot and through cb/pa switch to a avr which was usually 8v output there would be others 5v etc for various circuits that needed whatever, remember the last one was a tristar 777, but thats now in another galaxy far far away

did do one or two simple things last night, diddent find any shorts on the to220 trannies i diddent find any short/connection between any pin on the transformer i am no expert on transformers but from a unknolwedgable point of view i would think there should be a connection through it eg from the 4 pins on one side to the two pins on the other one thing, it dosent smell right this board, especially in that area. wonder if somebody has wrong wired plug at mains and burnt it out, it dosent have the original plug, the same wd40 guy, simplistic i know but you never know ive got to go and look at a car, so will be around later on usually ok with psu's, but in the past i would have a suspect and swap it out, process of elimination, sometimes a good way, if you catch it early, and not if you dont, we've all done that

Hi kevin havent gone deep into this board yet, was busy with drive unit ive nicked a pic off this site from an older post, hope thats ok firstly i will tell you what i have that is the same or similar to whats on here the white filter, the transformer, which looks the same but different part number and the relay itself plus various other generic bits like caps etc, the only bit i dont have for certain is the ic on the heatsink. later i will check the two trannies for shorts as the board is out of the deck, dont see q902 as such, q906 is connected directly to it, easy spot on this pic i might even have those trannies if it comes to that i will have to check against s50/520/470 part lists saw another 940 go on fleabay last week spares or repair around 90 quid seems the going rate these days, 3 years ago they were 60 quid'ish was suspecting the 5v because of a marantz cd player that did the same a few years ago, and thats what was shot

cheers gents, hope you are all well. i have made some progress, as you may remember there is another 940 here so thats handy, took a shortcut and put its relay board into this player, its a non uk one and the boot sale one is a uk one but as we know apart from the two obvious bits, internally there is no difference. plugged it in and you hear the satisfying click of the relay and the red light and it switches on with good display. its not a minter this 940 there some scratches and marks on it. now to the drive unit, closer look revieled lots of dust, crap and hair and somebody thought, its not working dear ill put some wd40 on it that'll sort it, took some time to get rid of as much as possible of that lot, then cleaned the laser, put a bit of lube on the sled, i use that stuff thats used on hornby trains, its very fine, just put a little on a cotton bud, then a bit of switch cleaner on that switch sensor for eject etc, remenents of the old belt were lying in the bottom below where belt goes, removed whats left of that and put a new one in, stuck it all back together and switched it on, and..... it works, plays no probs, sound no probs, now as we all know the biggie, record, i usually go via optical and rec, i mean stream off a well known platform, mustve done a good job on the drive as it records and writes toc with no fault. so defenetly a duff component on its own relay board, my money is on the 5v regulator, dont think ive got one of those, they are a 4 pin jobbie, this time fleabay is your friend about 5 quid for one on there from the uk will post a pic of offending board later

found a 940 at a boot sale, how rare is that, cumbria was never a minidisc paradise in the first place so peoples interest in them here is not great. guy said it dosent come on, thats ok, so took it home, when i checked, he's dead right, its dead jim ! good project i think, power supply problem, thats a new one, no light no click of relay no nowt. main fuse and power cable ok. got what i will call the relay board out now so going to check over that first, got some elna caps on there, they are not good, could be anything though. drive looks ok and owh looks ok, will get to that later at some point, no belt though, no suprise there, can easy service that up and stick it in another deck, to check that, still have a couple of 470's around. have parts off decks i have broken for spares in the past for psu parts, eg psu's out of an s50/520 and 470, so as long as its not the toroidal all is not lost.

can only compair just now between 930 and 980, 980 is a tad slicker than the 930, always was, i just put it down to the mdm 7 with its simple belt set up and not much holding back the 2 sliders, well, once its lifted into eject position sort of thing, one slider, and with the mdm 5's ive had anything to do with a much more complex gear driven set up and i just accepted that was normal, any other deck i have or have had was just the same, maybe some parts dry out over the years, that would be the only thing i could think of otherwise, dont think md decks are at the cracked gear with age point ...yet. buys, i bought a 470 before christmas, usual issues shot belt and this time a sticky sensor where disc would come out and would go stright back in again, sorted that and turned it round fairly quick, sold on a couple of 440/470's since then, i had quite a lot of those, at the end of the day one will have to remain as a player only as it has a dicky owh, can be a pain in the arse those, hope you are all well

been using a 930 as a dac for yonks on a marantz cd63ki, via rca coaxial, improves the sound quite a lot

cant remember reading this in any of these posts and rather simplistic suggestion but has anybody tried switch cleaner and exersised the micro switch at the front of the drive, ive had issues with those before, as it can be of the stay in standby symptoms.

all sorted, somebody had criss crossed the old belt which was shot, so replaced it and got at micro switch with switch cleaner, because of that, had to go in from the top,which i dont like to do, usually install belts through the front whilst holding the drive, less risky, whenever ive unlatched the top cradle and taken it off in the past i always miss the metal tab in the middle, no different this time, not tested record yet, but otherwise all good bye the way here is a risk it for a biscuit, anybody up for a dare if cheap enough https://www.ebay.co.uk/itm/134464198556

yes it was 480 in ad, and clearly 470 in pic, spares or repair though.