Teac FD-55B Floppy Oddity

From: John Chris Wren <jcwren_at_jcwren.com>
Date: Wed Feb 27 15:45:23 2002

        Indeed, my boards are P/N 15532001-01. Mine doesn't have a 7556-00, but a
7358-00. The 48 pin ASIC is the same. U8 is a 6-Unit 320mA Transistor
Array with Clamp Diode and Strobe, and probably most of it is used in the
stepper motor driver. They're probably using 1 of the channels to pull down
the head solenoid because of it's current capability. The silly
Mitsubishians have a dimensional drawing of the part, but no actual
datasheet.

        Would it be possible to get a copy of the schematics? Either a high
quality Xerox, or scan to PDF or something?

        --John

> -----Original Message-----
> From: owner-classiccmp_at_classiccmp.org
> [mailto:owner-classiccmp_at_classiccmp.org]On Behalf Of Tony Duell
> Sent: Wednesday, February 27, 2002 15:40 PM
> To: classiccmp_at_classiccmp.org
> Subject: Re: Teac FD-55B Floppy Oddity
>
>
> >
> > Thanks! Perhaps this will be a start towards debugging it.
> I do know that
> > the head load solenoid is on a 2x3 connector, and uses the two end pins.
> > Three of the remaining 4 pins go to the home position opto
> sensor, and the 4
>
> Sounds like it might be the same drive. It was late when I posted last
> night, and I didn't notice that the track 00 sensor uses pins 4,5,6 of J4
> also. Pins 1 and 2 of J4 go to the load solenoid.
>
> The schematic has 'P/N 15532001-XX' printed on it. Can you find that
> number on the PCB? It uses 2 ASICs, 1922-00 (mostly digital circuitry,
> looks to have about 48 pins) and 7556-00 (analoge read/write circuitry,
> looks to have 30 pins).
>
> -tony
>
>
Received on Wed Feb 27 2002 - 15:45:23 GMT

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