How to get around safeguard of the SAMSUNG HDD drives

[darthuggla]

Hi,

I would like to make a grinder from the old hdd drive. Like on this movie

I only have SAMSUNG hdd's. Unfortunately they all have safeguard which stops the engine after few seconds. It is probably because circuit is not detecting any incoming data from the head since I have removed the head. It would only disturb. I would like to use existing hdd circuit with some modifications (?)

On the video above someone bypassed safeguard by connecting 5V with something on the board using cable (older SAMSUNG hdd).

My hdd's have this board:



Engine is controlled by the HA13627 controller.

What can I do to prevent circuit from stoping the engine?

My thoughts:
1. May be there is a way to cross/apply voltage to some part and trick controller so it won't cut off power from the engine?
2. May be there is a way to cut/remove some parts of the paths so controller will not get the message to stop the engine?
3. May be there is a way to trick controller that it is getting data from the head by applying some voltage to the pins where the head was mounted?

Could someone help me with that. I have no clue how to approach this topic. I will be grateful for any help.

 

[123jack]

Fascinating...

Have you considered removing the circuit and driving the motor directly?
(with your own controller of course)

 

[darthuggla]

Hi 123jack, unfortunately I don't know anything about electronics.

What I have seen in the internet it is possible to run hdd engine using its own controller with modification.
I don't know how to exactly modify hdd circuit to make it possible
That's why I am asking for help. Maybe someone with knowledge of the HA13627 or hdd's will help me.

 

[betwixt]

I assume you realize these motors are quite low power and will probably stall if used as a grinder. They are only designed to be powerful enough to spin the platter and drag from the head is negligible. Most of the force you feel if you slow it with a finger is due to the mass of the platter, not the motor and being aluminum it wouldn't make a good grinding disk!

If you did manage to keep it running, the chances are you would damage the driver IC if you applied load to it.

Brian.

 

[darthuggla]

Hi Brian,
I am gonna to grind some plastic parts.
I am not gonna to stress it much.
Besides I have many broken samsung hdd's.
If one grinder fails I can replace it with another. They are only gathering dust on my shelf.

 

[123jack]

I had assumed this was a "learning" project.
If it's to do a job I'm with betwixt - it will save you
a good deal of time and money probably to use
a different motor. It might be worth converting one into
an office fan though?

 

[darthuggla]

Could we forget the purpose of the hdd engine and focus on the solution?

 

[d123]

Hi,

...Maybe pausing the video, taking a screenshot and zooming in to try to guess which pins they are?

I can only suggest looking for the datasheet, or a replacement part datasheet and finding out which pins you need to tamper with or whatever solution is needed - not an easy part to locate a datasheet for, so perhaps, but not necessarily it is a device specific part Hitachi make for Samsung(?) and have/see no need to release the datasheet - I couldn't find the chip on the Hitachi page either...

I found this page that may or may not be of use as it refers to an ST device and references the Hitachi chip for some reason:

https://es.scribd.com/doc/98214528/L7250-Smooth-HA13627-Hitachi-Motor-Driver

Sometimes trawling the Internet and repair forums/webs or related to your search come up with a page or two that can help.

Or, be very patient and expect little clarity from the exercise and get a tester and see which pins do what voltage-wise when the motor is on...

Good luck.