NGY Posted February 19, 2016 Report Share Posted February 19, 2016 Greetings to everyone - I am a newbie here, though not new to Minidisc. I entered the MD world in about '96-97, when I bought my MZ-R3 in a Duty-Free shop at London Heathrow, while waiting for connection. It was an amazing piece of kit that time, and I must say, the MD technology is still a fantastic engineering achievement in my eyes. I have been reading the forums since about two months now, mostly seeking for repair tips - having a couple units I bought recently second hand (mostly fairly cheap), with the intention of bringing them back to life and preserve. And, already a big "thank you" for the forum - I already managed to fix my MDS-JE510 unit, that did not accept discs, ejecting all with C13 error. Following Jim Hoggarth's instructions, I turned it back to fully functional, and it still holds since then. Now, I am in a project of repairing the unit in the subject. I tried a couple of things but still not yet there. This 530 arrived with a broken OWH (Overwrite head), that had clear signs of previous failed repair attempts, thus the machine was play only, but otherwise working OK. As a first step, I took a 100% OK OWH from a fully functional 520 unit, built it into the 530, but then the 530 still did not record, i.e., when ejecting after a record session, the disc remained blank. Testing the same OWH back in the 520: all OK. (BTW, I finally fixed that broken OWH from the 530, tried also in the 520, and the 520 just can record properly with this repaired one.) Error history in Error Display Mode shows E04 and E09 alternating ("Address cannot be read" and "Playback retry error" respectively). Then I took the service manual and began performing the checks (except for laser power and traverse signal, as my old oscilloscope gave up recently), and the only error I could find is a "7350" error in self-recording (and focus bias) check, obviously, as no data was written to the disc. Apart from that, the deck seems all fine, functioning as it has to. Having the idea the focus could be out of range, first I created a continuously recorded test disc in a spotless 330 unit, then put it back to the 530, and checked the focus bias with that. It went all OK, continuous play test showed all error rates below factory specs. Repeating the same procedure with a continuously recorded disc made with the 530, I got back to the "7350" error - as nothing was written on the disc. I am stuck here, I have no idea, why the unit is not recording, as everything seems OK. This particular deck run only 38 hours of recording, and 418 hours of playback, and looks like new - would be great to have it fully functional again, especially for the Type-R ATRAC. The schematics of the OWH drive circuit is fairly simple, pairs of diodes and transistors, plus a capacitive coupling to the writing coil - all these parts look robust on the BD board, I cannot even imagine they blew (or the IC driving the transistors?). I could only check the diodes, they seem to be OK, however, I have no means to check these special transistors. As soon as I can get my hands on another oscilloscope, will check the writing signals on a good unit, and compare with the 530, to see ho far the signal gets, and when it stops. But before that, if anybody with some experience can give me their view, whether I am going the right direction, or something else needs to be checked/adjusted. I am aware, that the time I will probably spend on fixing this may not worth it, and I may buy another unit at a lesser cost, but hey, this is a hobby, and I looked for some challenge :-) . Should I not succeed, I will put up the unit for parts, if it can help others to fix theirs. Thank you in advance and apologies for the fairly long post. Quote Link to comment Share on other sites More sharing options...
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