Atari 1050 - No Power

[Bazil]

Hi all

 

Wondered if someone could help me?

 

I have an Atari 1050 floppy disk drive that won't turn on.

 

I've done the following:

 

1. Power pack tested and giving 9v ac (also tested the drive with another power pack and still no luck)

2. Checked the output on Q7. Getting ~9v on input but 0v on output.

3. replaced CR17-CR20 still nothing

 

Any help, i would be very grateful

 

Thanks

[marcokitt2000]

Hello Bazel,

 

Oke Q7 has no 5v thats meaning Q8 must have 12v please check that.

Is the Q7 getting very hot?  But if you download the 1050 field service that will help many problems.

Replace Q7 if you have spare parts old 1050 pcb or order from electroshop.

1 question is the Q7 en Q8 on the back side where the heatsink is?

I have self a 1050 that power on leds ok but no motor and the stepping motor.

And the problem was Q8 no 12 volt and it gets very hot.

 

Gr.

Marco

 

atari-1050-field-service-manual.pdf

[+kheller2]

A slightly cleaner version, with a few of the missing pages returned to their proper location:

https://archive.org/details/1050FSMRebuiltAKH/

This is based on R3.  I've not seen any newer/revised versions (and I have a pile of them on the floor!) ?

 

[+bob1200xl]

If Q7 has 9v at the input and zero volts at the output, you either have a short on the output or Q7 is bad. Measure the resistance to ground at the output of Q7 (power off, please). If it is close to zero ohms, you have a short/failure somewhere in the output circuit of Q7. If not, try replacing Q7.

 

Bob

 

[_The Doctor__]

check the caps before and after the regulators, and the diodes... finally the regulators themselves..