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MDS-B6P eject problem

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I bought an MDS-B6P off ebay that wasn't powering on. I got the power problem fixed (the person who fixed it for me said something about standby mode and a bad transistor). The deck seems to be working ok apart from the fact it won't eject discs. It displays "Impossible" when the eject button is pressed, and just stops playing the disc. I can still get the discs out by rotating the wheel at the back of the loading mechanism (I have the cover off). The stop and eject buttons also have to be pressed fairly hard to get a response, I suppose I could use some contact cleaner on them.

Can anyone help me? Thanks.

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Well upon examining it more I have some information:

 

If using a prerecorded disc and pressing eject, the display first says "Premastered" before "Impossible". If using a recordable with the write protection tab in, it says "Write-protected". It seems the machine thinks the eject button is some edit command (Even though this is a playback only deck, I suppose it has much the same software as the MDS-B5). 

 

If I continue to press the button, I can get the display to read "Eject" and "No disc" but it never ejects, instead it reads the TOC as if I have just put in the disc.

 

 

Thanks.

 

edit: quick video, this is a recordable MD without write-protection enabled

 

 

And one with a prerecorded MD:

 

 

BTW I didn't find the service manual or user manual helpful (no troubleshooting guide).

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Very strange.

It's like if the eject button is interpreted by the software like a REC button. It can arrive if the switch is bad because it can make some electrical glitches on signal. Or a resistor.

But as you bought the unit from eBay you didn't know anything about the past of this device ?

Possible that some parts like microprocessors had been mixed with a B5 ?

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Very interesting you should mention these things...

 

I had noticed one of the white ribbon cables was cut a little on one side, but I didn't think it completely severed the conductor. When I looked around, I noticed that another ribbon - the one coming from the front panel - had been compressed. It was squeezed together between the edge of the board and the top cover support - exactly what would happen if someone pressed too hard on top of the player, and it does seem the top cover has some depression to it. 

 

Looking around a bit more, I found that one chip - on the right side upright board - indeed says MDS-B5! It remains to be seen if this was changed or the two machines use the same component. Tonight I will start looking over the service manual to see what those ribbon cables do, and what components are listed.

 

Thank you for pointing me in the right direction... those ribbon cables seem to carry the eject button signal judging by their placement.

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I wasn't sure how to check the cables (I have a multimeter but I'm more experienced with cars) but I found a replacement cable on ebay for only $15. Should be here by Tuesday. I did check the version before I took it apart... maybe 1.4? Can't really remember so I will check that again.

 

This is the best picture I could get of the damaged area. It is the display board cable.

 

KIMG0132.jpg

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I wasn't sure how to check the cables (I have a multimeter but I'm more experienced with cars) but I found a replacement cable on ebay for only $15. Should be here by Tuesday.

 

 

If it's a digital multimeter : put your multimeter in diode mode function.

 

Make touching the two probes to have contact and you should here a bip or buzzer and read 0 on LCD display when contact.

Put probes on both side of the ribbon cable and test each pin to check if continuity between each side.

 

fig9_multimeter-continuity-test-beep.jpg

 

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