How do I erase tape on sony microcassett

It sounds to me that you might have a mechanical problem in the machine. I am not familiar with this machine, but I have worked on lots of tape machines. The belts and rubber pieces can get slick or stretched causing problems.

Probably has a bad sensor belt (small belt attached to silver and black reflective wheel).

Head unit needs azimuth adjusted

check the headset and or the headset connection.

here's the manual of this recorder. You can take a look at it to see if there are any explanations regarding the error:
http://ec1.images-amazon.com/media/i3d/01/A/man-migrate/MANUAL000033419.pdf

Hello,

This unit does not have erase. You can use a microcassette tape eraser which you slide the tape thru.

Hello sorry the M-2000 don't have the ERASE feature but your only option is to get a tape eraser you can get one at http://www.tvps.com/Products/ECS-ME20-Mini--Micro-Cassette-Eraser---New__VE-ME-20.aspx just think positive your unit will last longer the eraser prolong the life of units just pass the microcassete once on the eraser and is done full erase :)

Hello unfortunately this unit don't have a erase function the only thing you can get a Microcassette eraser this eraser will help even if you decide to buy any micro or mini cassette transcriber when you used the erase function on the unit the life on the head, rewind, gears and motors get reduced by using this method if you used and eraser it erase the tape Magnets are on top and bottom eliminating the need to flip the tape allowing complete erasure on one second heare is a eraser you can buy and it is cheaper than buying other unit. http://www.tvps.com/Products/ECS-ME20-Mini--Micro-Cassette-Eraser---New__VE-ME-20.aspx

use a bulk magnetic tape eraser from radio shack. the eraser head in your machine is mal-adjusted and, would be too difficult to fix

I have a Soney Transcriber BM-840. 'When I press the erase/rewinder buttons, the tape IS NOT erased. What am I doing wrong?