andy29 Posted December 27, 2015 Report Share Posted December 27, 2015 Hello, carrying on from my post a while ago - thanks for your help - I now have an MZ-R30. Everything appears to be working fine, except that the pause button is very hit and miss, and the display and mode buttons only work some of the time, too. Occasionally the pause button will work with a light press, but most of the time it only works when pressed quite hard (which I obviously don't keep doing). I see that this kind of thing is mentioned in the Minidisc.org FAQ: "My portable MZ-R35 Minidisc player/recorder is 2 years old and works very well, except for the display and mode buttons." "The problem you mentioned is very common with the MZ-R35 and with the MZ-R30. In most cases it is not because of direct damage to the 2 keys you mentioned. It is related to the 3 keys mounted on the right side of the recording switch (the red one). In some cases the only problem is with the display and mode keys." Does anybody know what that actually means - what is usually wrong with the pause/vol-/vol+ buttons? I have opened the recorder and had a look, and at a glance everything looks okay. If I press the pause button directly with my finger it works better but still not perfectly, and if I short the button's pins where they're soldered to the board, it is still only works sometimes. The volume ones work easily and consistently if I do the same thing with them. That makes me wonder if it's more to do with the solder connections either on the button or the side of the board, or something worse. I thought it would be a good idea to ask here first before I do anything, since you guys know what you're doing. Quote Link to comment Share on other sites More sharing options...
sfbp Posted December 27, 2015 Report Share Posted December 27, 2015 More likely a power adjustment needs to be made. You will need a regulated powersupply on your lab bench to do this. Quote Link to comment Share on other sites More sharing options...
andy29 Posted December 28, 2015 Author Report Share Posted December 28, 2015 Thanks... I see you've recently been talking about power supply adjustments in the N510 thread below this one... is that the kind of thing you mean? I guess that might actually be easier to do than replacing parts, as long as it doesn't need special discs, etc. I do have a proper bench power supply. Looking at the R30 service manual it doesn't seem to have as many settings available as the N510 - just a 'power supply discrimination test' and a 'charge test' unless I've missed something. Are they what I want or am I going in the wrong direction entirely? Quote Link to comment Share on other sites More sharing options...
sfbp Posted December 28, 2015 Report Share Posted December 28, 2015 Exactly. Unlike later models (I have never worked on an R30) there's nothing saying exactly what you should be adjusting and what levels to expect. This may take some poking around in earlier and later models' service manuals (Sony often omitted to repeat stuff that was the same between upgrades). I note that there's no "key check" which is a semi-automated way to make sure every button works. Doesn't mean it's not there, though. Quote Link to comment Share on other sites More sharing options...
andy29 Posted December 28, 2015 Author Report Share Posted December 28, 2015 It is 'feeling' more like some kind of voltage problem, because I tried running it with the lithium cell inside (I hadn't bothered before - it is 0.8v (!) and it was otherwise working fine with the AA holder on its own) and the keys feel about 75% reliable rather than about 25% without it. It certainly seems to make a difference when it's in. I had a look at the service menu and it ties up with the service manual like it should. I didn't see any settings it didn't mention, though I was of course being ultra careful and not pressing anything unless I was completely confident about what it would do, so it's possible that I missed things. It's almost like you can't adjust the voltage settings using the menu like you can on the later models? Mine only seems to have the power supply discrimination test and charge test in the power supply mode, where the later manuals show many more values which can be set. I can't see any 'manual' and 'overall' modes like the later ones either, just servo/audia/mecha/power/assy. I can go back in and note down what I do have in the power mode, if that might help, and in case there are more values there than I thought. But even then, is it possible to work out what should be what, what test points to use and so on? I'm starting to wonder if the lack of instructions from Sony might ruin the whole thing. Sorry if I start to be awkward, I wish I understood this more. Quote Link to comment Share on other sites More sharing options...
sfbp Posted December 28, 2015 Report Share Posted December 28, 2015 You're doing fine. I double-checked a couple of hours ago and came to roughly the same conclusions. Sony does helpfully put a lot of "expected" voltages on the Schematics. You're going to have to become familiar with them, starting with the one for the power board. I can't help since I don't have an R30 to compare, but the diagrams should be a pretty good reference. Quote Link to comment Share on other sites More sharing options...
andy29 Posted December 29, 2015 Author Report Share Posted December 29, 2015 Heh, thanks, well I am possibly getting close to the limit of my abilities now, but I'll take my time with it. Looks like you need to de-solder the power board from the battery connections to get to the test points on the other side. But maybe it's not so bad. I suppose I just need to check voltages until I find that some are wrong, and move onto the main board if I don't find any... or is there something more specific I should aim for? I see the voltages on the schematic now, thanks for pointing that out. Quote Link to comment Share on other sites More sharing options...
sfbp Posted December 29, 2015 Report Share Posted December 29, 2015 Don't worry about things that are plain WRONG... eg 0 instead of +3 or whatever. What you're looking for is voltages that are more than a couple of percent BELOW what they should be when the bare minimum is supplied to the power terminals. It needs to work even with the battery almost exhausted, see? That's why the bench PS is so useful. But again, I cannot be sure of the relevance to this model. It may be that all was much simpler back then. The other thing is to try to clean any contacts for buttons, although the press-bubble type probably cannot be fixed by doing this... should be sealed and stay sealed. Quote Link to comment Share on other sites More sharing options...
andy29 Posted December 29, 2015 Author Report Share Posted December 29, 2015 Ah ok. I figured that not all of them would be there since you don't have either type of battery connected, if that's the reason why. Yes, I can see that you need to try it with a low voltage - if only my 3.6v lithium cell was working, I wonder if that would take the voltages away from their limits where they get flaky and show that it can work as it should. Maybe that's why even a dead cell sometimes helps it a little. So what happens if I find a low voltage, is it then a case of looking for bad components or joints, or will there be places to make adjustments? I appreciate you don't know everything about the R30, I will have to have a look at the schematics again, I guess something should say. I did try cleaning the buttons as the first thing I did, but yes, they look like they're sealed and it didn't help at all. I am still wondering if I should reflow the solder joints between the switch board and the power board. I will have to have another look but if I put some small pressure on it, the pause/vol-/vol+ buttons do seem to work better. Maybe the lithium cell was pressing against the spring, pushing the board slightly, and creating a red herring... Quote Link to comment Share on other sites More sharing options...
sfbp Posted December 29, 2015 Report Share Posted December 29, 2015 Is this the right battery? (sorry in a rush, if its the same as R50 then you could try that one....) http://www.powerexpert.co.uk/digital-camera-battery/Sony/LIP-8.html Quote Link to comment Share on other sites More sharing options...
andy29 Posted December 29, 2015 Author Report Share Posted December 29, 2015 No problem It needs a LIP-12, but that site has one of those too. I think the battery connections were part of what had to be desoldered to remove the power board (I will check), and if they were, I wonder if I could use the bench supply to give it a nice stable 3.6v DC. Unless it would kill the charging function, or the connection isn't quite so straightforward. Edit: Yep, there are connections for Li+ and Li-. They're marked as test points in the schematic, straight through to the battery, unless they miss out details. Quote Link to comment Share on other sites More sharing options...
andy29 Posted January 7, 2016 Author Report Share Posted January 7, 2016 It was the solder joints! The pause/vol-/vol+ switches are on a board which slots into the power board at a right angle, and there are three solder connections which connect them together. They were cracked. Redid them and it works great. Thanks for your help sfbp... even sat here looking at them they didn't really look too bad so there's no way you could have known. I wonder if you have any thoughts about another small problem though (I hadn't really used it other than a quick test of everything, so I didn't see it). Sometimes if I press lightly on the front (as you do when you push the record button), the whole thing will turn off and I need to remove power to get it going again. Sometimes when inserting a disc it says 'no disc', shutting the door a little more firmly stops that. I think I've narrowed it down to what appears to be the 'disc inserted' switch. In the recorder, it's in the front left corner, next to the write protect detection switch. It keeps working if I fix it down with some tape, or put a ~1mm pile of tape on the disc, so maybe it's not quite getting pushed down enough. Attempting to clean the switch didn't do anything and the metal which holds the disc doesn't look bent upwards so I'm not really sure what else to try. I wanted to check the switch more closely, but I cannot make the mainboard's screws move, so I can't get to the other side. I don't know if you think it's best to use a bit of tape to hold it down and just leave it at that? Quote Link to comment Share on other sites More sharing options...
sfbp Posted January 7, 2016 Report Share Posted January 7, 2016 I wouldn't tape it. Well done on the button by the way - those models were rather simpler in design, and you know what they say.... and there's less to go wrong. The microswitches can jam.However the whole system for keeping your MDs intact depends on it knowing when/when not inserted.You can try an air can, or conceivably some contact cleaner if you are careful and get rid of everything afterwards. Jim would know, but (sad refrain) he has not been heard of in months. Quote Link to comment Share on other sites More sharing options...
andy29 Posted January 8, 2016 Author Report Share Posted January 8, 2016 Thanks, I was lucky that was the problem really. It could have been a lot worse. I'm glad it was something that was even repairable. I tried the air but unfortunately nothing has changed, sadly. I suppose the switches are pretty much sealed up. I have taken the tape off. I was worried about getting sticky gunk into the switch or anywhere else too so there's another reason for leaving it off. Yes, I've looked at this forum a lot and I noticed about Jim. I don't have many discs in use - 4 plain black TDK MD-RXGs; a couple of other, coloured TDKs; a couple of 'HiSpace' ones; one pre-recorded disc. All working fine in my two other recorders. After swapping discs way more than I would like to in such an old machine, I've come to the conclusion that it doesn't like the RXGs. No idea why... they're just minidiscs... nothing is bent, nothing looks unusual or wrong. It's not like it's reading them and rejecting them, unless it does it extremely fast and I'm mistaken? It's something to do with that switch. I can make it go off with the others very, very occasionally, but it is consistent with the RXGs. But again I'm glad it works as much as it does. Quote Link to comment Share on other sites More sharing options...
sfbp Posted January 8, 2016 Report Share Posted January 8, 2016 RXG is one of the only disks I have consistently noticed problems with. Most of TDK's are brilliant. Maybe it's something to do with the transparent top. Quote Link to comment Share on other sites More sharing options...
andy29 Posted January 19, 2016 Author Report Share Posted January 19, 2016 Edit: For the answer to the original purpose of this thread, the problem for me was bad solder joints. The pause/vol-/vol+ switches are on a board which slots into the power board at a right angle, and after reflowing the solder that joins them (I think it was three connections), the problem went away. After some use I still don't know what it is... I can literally brush lightly on the front and it'll go off. It's just those black RXGs - I know what you said, but in my case it's the clear coloured ones which work okay! Time after time. So strange. Anyway, I am pleased with this old R30... after seeing its insides, I am amazed that all of the fragile parts still work fine after all this time, especially on a portable. And in some ways it's better than my NF-610, having a microphone socket and timestamp recording, for example. Even the disc usage display is useful. Quote Link to comment Share on other sites More sharing options...
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