My HD needs ground ...

[ptek]

Hello

When I got a 3.5" HD for my A1200 years ago, I took both to a guy at an local Amiga store for him to install it with a 3.5" to 2.5" cable adapter (done by him). Everything worked fine. I got a flatcable extension short enough just to move the damn noisy HD into a box and put the Amiga on top of it.

The HD worked fine for several years. More recently, it stopped booting and it acts like it isn't powered (no spinning, no noise, nothing).

Then I open the Amiga and found this curious fact : the HD power plug doesn't have any ground cable connected! I wonder how did it ever worked. I check from this link http://www.hardwarebook.info/3.5%22_Power that only the pin 1 and 4 are wired. The voltage between them is about 8.6V (close to the theoretic expected 7V)

Anyway, the HD is fine - I plugged it on a PC and it of course sounded alive and I also managed to boot it from WinUAE.

I just need some advice from where to get a ground signal safely (I know the parallel port have ground and some other devices but I wouldn't like to blow up my fully working Amiga)

If you want to look at the place were the 5V and 12V are obtained look at the picture ... the red and black wires that go out of the Amiga go into the HD plug.
http://img164.imageshack.us/img164/9594/amigahd2mn0.jpg

[ptek]

Adding a ground will not hurt, but I surmise your real problem is in the cabling. Attaching an extension, while reducing from 3.5" to 2.5" cabling has got to produce stress. Especially after years of wear, jiggling about, vacuuming, etc.

I think it must be a power issue (maybe ground) since if I turn on the Amiga with the faltcable disconnected the HD still doesn't spin. I think it should spin even there is no flatcable connected. At least, it happens when I power it on a PC without the data flatcable. I also remember I already tried to power the HD from a PC PSU while keeping the data flatcable attached on the Amiga - not a healthy maybe solution but it booted.

I'll try getting the ground as suggested and post the results later.

thanks all

[ptek]

You can use the ground connection at the floppy drive power connector. The two middle pins are ground. The outer pins are +5V and +12V.

I'm going to try that. Must I connect the 2 ground connectors to the respective ground connectors on the HD plug or one one is needed ?

Another question : I will have to cram 2 wires into a single connector (like he did). Will I need any special tool ? I never used a connector like this. Is there any other accessible ground source ?

[ptek]

SteveSMS wrote:

The best would be to get a molex connector from an old PSU, and solder it.

I already have it. Solder it to the floppy connector?!

Make sure you get some heat-shrink tubing

Why the need for heatshink?

If you want i'll post some pics how i did it.

Yes please do
Thanks

[ptek]

I'm just surprised how stupid I was! The data cable was inverted! Not healthy since pin 1 have some voltage, I think.

So everything works again. And "look ma, go ground"

Anyway I guess i'll dig at the forums for a flash disk replacement. 1 Gig will be the double I have on the HD and will fit inside the Amiga and it's quiet. Any suggestions?
I wonder if i'll notice any speed difference in reading operations. I don't pretend to write often at these times.

I use the A1200 normal non-buffered IDE port for the HD.

Thanks

[ptek]

Hmm, yes, you forgot to mention that you had broken it yourself

well, that was implicit It must have happened when I tried to plug the HD to the PC for trying UAE and plugged it wrongly at the Amiga. But it works, nothing was damaged (as it looks).

If the replacement drive takes more current than the present one (It will be written on the label on the drive), then I would advise you to do the molex modification mentioned earlier.

I'll go for a flash drive. I guess (hope) it uses less current. Anyway I'm using an old brick PSU of 60W from a Amiga 500 since my A1200 PSU died - I bet it was the HD demands that knocked it off...