• Please review our updated Terms and Rules here

ST-225 speed up and down?

F

framer

Veteran Member
Joined
Nov 27, 2008
Messages
582
Location
Murrell's Inlet SC
I've had an old ST-225 drive that I've been using for a decade go bad. I could still get it to boot but after 15-30 minutes I hear the drive spin down then back up then down and stops at some point. I believe it might be a heat issue as after it cools down it will boot again.

Any clue what to look at? Nothing looks bad visually, I'm thinking a power transistor???

Thanks,

framer
 
I have drives that do that immediately, without any possibility of heat effects so it might not be heat related. FWIW, those drives are all useless.
 
First try it with a different power supply. It may be that your system's power supply is getting weak.

If it still does that with a different power supply, then at least it is probably something on the logic board. It might be less complicated just to swap a board from a crashed similar revision ST-225.

Sounds more like a bad solder joint to me. Any electrolytic capacitors would also be suspect these days.
 
There are a few electrolytics on the 225, but I think they are just filters. Don’t know for sure though. However, it couldn’t hurt to replace them at this point.
 
Very much sounds like a thermal issue around the motor driver, or the speed control circuit.
If you remove the drive from the machine and keep a fan on it, does it take longer before failing?
 
I think that's what's wrong with mine. They spin up to their max speed and then shut down, try to spin up, again, and shut down again.

Other than bearings are there other places to look? FWIW, the drives I have that do this are not ST-225s.
 
Stone said:
Other than bearings are there other places to look? FWIW, the drives I have that do this are not ST-225s.
Click to expand...
If your power is good, and the bearings don't sound bad, I'd suspect something in the motor control circuitry, or the sensor that reads the index pulse. But when it has such control, a drive's microcontroller can shut down the motor for whatever reason it wants, which can also include problems moving or communicating with the drive heads.
 
SomeGuy said:
If your power is good, and the bearings don't sound bad, I'd suspect something in the motor control circuitry, or the sensor that reads the index pulse. But when it has such control, a drive's microcontroller can shut down the motor for whatever reason it wants, which can also include problems moving or communicating with the drive heads.
Click to expand...
In that case... I hope it's the bearings. :)
 
Other things that will cause the spindle motor to shut down without restarting include a bad servo track on drives that use that positioning technology. The drive is then essentially trash, as there's no way for the hobbyist to rewrite a servo track.
 
Chuck(G) said:
Other things that will cause the spindle motor to shut down without restarting include a bad servo track on drives that use that positioning technology. The drive is then essentially trash, as there's no way for the hobbyist to rewrite a servo track.
Click to expand...
On MFM drives? Isn't that what we have here?
 
This is the 225. While it does have an onboard microcontroller it does little to monitor drive health. It also has no comprehension of what pre-existing data might be on select tracks or regions for calibration and relies heavily on the host controller to make those decisions. It doesn't even have the smarts to auto-park yet, let alone blink the LED if it detects a fault. I still blame a thermal issue with something in the motor drive circuit, or the DC-UNSAFE trigger is resetting the microcontroller and perhaps it's spin cycling?
 
Well it looks like replies are all over the place.

More info, drive sounds fine when running. I had another st-225 and have install it. It runs fine in the system. Feeling like the drive is OK I going to keep the drive and keep my eye on finding another ST-225 that I can use the controller board.

I was hoping it might be a known problem. Thanks for all the replies it helps confirm what to do.

framer
 
You must log in or register to reply here.
Back
Top