Atari SH204 hard disk

[robbo007]

Hi guys,

I've sourced an Atari SH204 external harddisk. Troubleshooting I've found that if the actual Tandon hard disk is connected to the case power it seems to short the PSU. Makes a ticking sound on the PSU and the fan does not spin. When I disconnect the hard disk the case turns on and LED lights up and fan spins. What could be causing the soft? Is the hard disk stuffed?

 

Regards,

Rob

[Jfcatari]

The HD is probably toast.   Is the drive SCSI or MFM?  

 

If it is SCSI you can look at one of the Zulu SCSI devices or a Blue SCSI / Blue SCSI V2 project.  All of these use SD card for storage.

[robbo007]

Hi, its the MFM Tandon Tm362 21mb.. Its gotta be something on the hard disk board. As it only seems to "short" when the hard disk is plugged in. I need a schematic I think of the hard disk board so I can see where the power is going. Would be nice to fix it as the owner said it did work a few years back but when he took it out of storage it did not work. hmmmm

 

Edited Monday at 08:31 PM by robbo007

[macsonny]

14 hours ago, robbo007 said:

Hi guys,

I've sourced an Atari SH204 external harddisk. Troubleshooting I've found that if the actual Tandon hard disk is connected to the case power it seems to short the PSU. Makes a ticking sound on the PSU and the fan does not spin. When I disconnect the hard disk the case turns on and LED lights up and fan spins. What could be causing the soft? Is the hard disk stuffed?

 

Regards,

Rob

I had the exact same problem. Ended up being a blown capacitor on the hard drive mother board. It was a 20 cent part to replace. Suggest you have a look at the main board of the hard drive and see if you can see any failed/burnt components.

 

Good luck!

[robbo007]

Thanks. Yeah I will remove and test each ceramic cap one at a time until I find it. A visual inspection shows now blown caps. Regards.

[macsonny]

33 minutes ago, robbo007 said:

Thanks. Yeah I will remove and test each ceramic cap one at a time until I find it. A visual inspection shows now blown caps. Regards.

It was actually a tantalum cap that blew in my unit.

 

I forgot to mention I gave the drive a couple of good "thumps" as I suspected there was head "stuction" causing the drive not to spin and hence burning out the capacitor. I was 100% right as drive spun up fine after a few good thumps and replacing the cap.

[robbo007]

Hi, Well its seems to be Capacitor C5. I removed C1 C2 and C51 tested and then C5. They are all the same type "106 +25 K" What are these? Polarized Tantalum? Would they be 10uF 25v ?What I can't see it the indication on the motherboard for negative if they are polarized. Did not take note in which way they were facing. 

Thanks,

Rob

[TGB1718]

Usually they will be connected between some +VE voltage and the 0V line, use a meter and look for

which pad is connected to the 0V line