Common Issues & Repairs
Most MD equipment was well made and still works to this day. But there are some common (and not so common) issues that may need fixing.
Corroded battery terminals
The Ni-MH and disposable cells used in most MD portables are prone to leaking after time. This means that many used devices have corrosion on their battery terminals that will make the device fail to work or work unreliably (power loss while writing or moving the device, constant low battery warnings)
The best way to clean corrosion is a mild acid - lemon juice or white vinegar is the best. Dip a cotton swab in the acid and wipe the corroded metal. Then wait a few minutes and clean up any residue with a swab dipped in isopropyl alcohol.
This will not restore any “eaten” metal, but it will remove the gunk that may be interfering with the connection. If hardly any metal remains, try a small piece of aluminium foil between the contacts and the battery terminal. If that works, then you may be able to find a more permanent piece of metal to use instead.
Deck not ejecting discs
Unlike tape formats, (most) MD equipment does not use a belt to spin the disc. Many decks do have a belt for the eject mechanism, though, and this can fail as all belts do.
We have a guide for replacing the belt in a Sony MDM-7 drive mechanism used in the MDS-E12 pro deck.
Number of belts in Sony MDM drive:
- MDM-1 x1
- MDM-2 x1 (Sony 4-967-656-01)
- MDM-3 x1?
- MDM-4 ?? (JA30ES)
- MDM-5 None
- MDM-6 ?? (JA20ES)
- MDM-7 x1 (17mm x 0.8mm square)
Sony MDS-JE500 and MDS-JE510 Eject Issues
https://www.digikey.com/en/products/detail/c-k/SDS004/1949299 Sony decks MDS-JE500 and MDS-JE510 can have issues with automatically powering on and continuously attempting to eject the disk. This is caused by corroded contacts inside of a microswitch used to detect if the carrier is in the fully unloaded position. This guide describes the process of tearing down the unit to get at the switch to replace it.
Decks - tarnished ribbon cables
In Sony decks (at least models from around 1996 onwards), there are two FFC (flat flexible cables) from the MD drive to the main PCB. These can become tarnished (oxidised) and prevent the machine working properly. If you are having issues with your machine reading discs then it can be worth withdrawing and reinserting these FFCs a couple of times. The act of doing this “wipes” the exposed ends of the FFC on the spring loaded terminals and usually cuts through the oxidation. In some cases it can be worth replacing these FFCs, they are usually only a couple of dollars/pounds/euros from an eBay retailer.
Decks - won't come out of standby
This is the single most common issue that causes owners to start ripping the guts out of their machines. This invariably ends badly with a completely wrecked machine.
STOP
Check the MD drive is in its “home” position as it would be if the disc was ejected fully and properly. On later MDM7 drives (x40 and later machines), ensure the white slider that sticks out the rear of the drive is fully “in”. Push gently if required. Also ensure the load/eject belt is good and replace if suspect. You don't need to mess with the position of the laser sled, the deck will “home” it when it initialises.