cjctan Posted April 3, 2021 Report Share Posted April 3, 2021 Hi, Does anyone knows how to get into the test or service mode? I can't find it in the service manual. Many Thanks! Quote Link to comment Share on other sites More sharing options...
kgallen Posted April 3, 2021 Report Share Posted April 3, 2021 Hi. Sorry I can't help, I find the same as you - no detail about this in the service manual. I had a bit of a google and couldn't find anything. Maybe worth having more of a search around Tascam or Teac's other MD machines (301, 501) to see if any resource details entering service mode then see if a similar key sequence works on the 350. On Sony decks, this usually involves holding a set of front panel keys whilst energising the device, so you might end up at some hit and miss trials on the MD-350. If you find anything, please document here for others! Kevin ETA: This is for the MD-CD1, but this has two Eject buttons for the MD and CD drives, so this won't work on the MD-350. However what it suggests to me is that Tascam don't use an overly complex sequence. Sony decks often require 3 buttons to be pressed whilst turning on, which can be a challenge! Quote Link to comment Share on other sites More sharing options...
kgallen Posted April 3, 2021 Report Share Posted April 3, 2021 Well I've been playing about with my MD-350 for a while now. Of the very many I've tried, I can’t seem to find any sort of button combination that gets me in to any Service Mode (holding buttons in whilst turning on with the power switch[*] and continue to hold buttons for a while longer). I now seem to have got a little distracted with playing with SP/LP2/LP4... so that's today gone! [*] The MD-350 has a "proper" clunky on/off switch, not a standby/on like the domestic Sony MDS decks. Quote Link to comment Share on other sites More sharing options...
NGY Posted April 3, 2021 Report Share Posted April 3, 2021 I don't currently have access to an MD-350, therefore cannot try it: would the STOP+PLAY+READY combination (buttons being kept pressed simultaneously while powering up the machine) work on this model? Quote Link to comment Share on other sites More sharing options...
cjctan Posted April 4, 2021 Author Report Share Posted April 4, 2021 Hi Kevin and NGY, Thanks for the replies and suggestions. So far I have tried to look for other service manuals such as the MD-301 but only can find the MD-CD1 that mentioned about the service mode (shown in Kevin's post) I also tried the "Stop+play+ready" as suggested by NGY but failed. I have been in the mood to replace the faulty optical pickup for both my Sony MDS-JB940 and Tascam MD-350. The Sony is much easier to replace and adjust the laser power value in the service mode. I do not have a laser power meter to make accurate adjustments and hence just relying on the setting inside the service mode Quote Link to comment Share on other sites More sharing options...
BearBoy Posted April 4, 2021 Report Share Posted April 4, 2021 16 hours ago, kgallen said: I now seem to have got a little distracted with playing with SP/LP2/LP4... so that's today gone! What were you doing, Kevin? Comparing the sound quality? Quote Link to comment Share on other sites More sharing options...
NGY Posted April 4, 2021 Report Share Posted April 4, 2021 9 hours ago, cjctan said: I do not have a laser power meter to make accurate adjustments and hence just relying on the setting inside the service mode If you replace the OP-s, it is highly recommended to have an LPM as well as a test jig for IOP. What you see inside service mode is not an actual measurement of the laser power. It is rather a "fine pitch scale", along which you can fine tune the laser emission (by about 0,045 mW per step or so on the Sony, not sure about the Tascam), but those are relative steps. You need to adjust your OP to an absolute laser power value, then check IOP against the acceptable range, both as specified in the SM. Quote Link to comment Share on other sites More sharing options...
cjctan Posted April 5, 2021 Author Report Share Posted April 5, 2021 14 hours ago, NGY said: If you replace the OP-s, it is highly recommended to have an LPM as well as a test jig for IOP. What you see inside service mode is not an actual measurement of the laser power. It is rather a "fine pitch scale", along which you can fine tune the laser emission (by about 0,045 mW per step or so on the Sony, not sure about the Tascam), but those are relative steps. You need to adjust your OP to an absolute laser power value, then check IOP against the acceptable range, both as specified in the SM. Understand your advice but getting a LPM is out of my league thats why i have to rely on the ballpark IOP value printed on the pickup. Thanks for your input! Quote Link to comment Share on other sites More sharing options...
NGY Posted April 5, 2021 Report Share Posted April 5, 2021 7 hours ago, cjctan said: i have to rely on the ballpark IOP value printed on the pickup. OK, I trust you know what you are doing, and hopefully you are also aware of what those IOP settings in service mode are meaning/impacting. If you keep the IOP closely around the value on the OP sticker, you certainly cannot go too wrong - your laser might still not be in the needed range (where it is properly operating), but at least excess IOP will not kill it (= will not speed up its ageing). Quote Link to comment Share on other sites More sharing options...
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