Quadra 840av, SCSI Controller dead?

[chiaki]

My Quadra 840av dont boot from any SCSI-Devices at boot.

When i boot the Mac OS 7.5 floppy, the apple drive setup tool say that the harddisk doesnt contain any valid partitions, and it cant format it. :'(

I test it on the internal and external SCSI-Bus, with ZIP100 and my 2Gb Harddisk from the Quadra 700 (my Quadra 700 can read and boot from the DIsk)

 

[System7]

Check the IC for damage.

 

[trag]

The 53C96 chip is not very difficult to find. However, do you have the ability to desolder and solder a 100 pin QFP or know someone who does?

 

[Bolle]

chiakis board isnt physically damaged as far as i could tell when looking at it

 

[Microns]

Have you reset the logic board? A logic board reset sometimes un-confuses the automatic termination that this model uses for internal SCSI devices. The written reset procedure is worth finding. Look in the 840av owners manual that is available as a pdf on the interweb.

 

[applefreak]

Reset Logic Board - Quadra 840av

Before you begin, remove the following:

•Cover

•Power Cord

•Logic Board

Unplug the computer first.

Using a small flat-blade screwdriver, pry open the latch at the end of the battery holder and lift off the cover.

Grasp the battery and remove it from the holder.

Press the computer’s power-on button. Verify that the power supply cable is disconnected from the logic board.

Wait 5—10 minutes and then

•Replace the battery

•Reassemble the computer

Note:

Make sure the battery in installed in the correct +/- direction.

Note:

This procedure resets PRAM. Be sure to check the computer’s time/date and other system parameter settings.