Lobo 5.25" Drive info?

5 posts / 0 new
Last post
Offline
Last seen: 6 days 12 hours ago
Joined: Nov 6 2021 - 14:38
Posts: 11
Lobo 5.25" Drive info?
AttachmentSize
Image icon IMG_0887.jpg4.09 MB

Does anyone have any experience with the Lobo 5.25" drives for Apple II's? I have one here that is non-functioning --- in fact, plugging it in to the Disk II controller prevents the system from booting at all. I'm quite certain the cable is connected at both ends properly. I'm having a lot of difficulty finding any information about these drives at all... and I also can't seem to find any information on why plugging a drive in would prevent a system from booting. Any thoughts?

 

 

 

 

amauget's picture
Offline
Last seen: 4 days 22 hours ago
Joined: Jan 3 2011 - 11:34
Posts: 327
Short circuit ?

Greetings,

This Lobo card seems to be very close to the Disk II analog card.

Anyway, when you say that connecting the drive prevents the system from booting, does it powered on ? If so, what is displayed on the screen ?

If there is no sign of life (power on light does not lit), there is probably a short circuit somewhere. Have you tried to boot only with the controller card in the Apple, without connecting the drive ?

Regards,

Antony

Offline
Last seen: 6 days 12 hours ago
Joined: Nov 6 2021 - 14:38
Posts: 11
I think so...

Thanks for the response!

I apologise for not including more info - I should know better...

So, nothing appears on the screen, and there's no beep. The only 'response' is a slight ticking noise from the PSU.

The controller works fine with other drives, so I'm also thinking it's a short somewhere in the drive.

I experienced a similar symptom with a recently-acquired IIc in which power-on resulted in a quiet, high-pitched whine from the PSU - the culprit was that the drive had been connected incorrectly by the last person inside (and of course the drive has subsequently been damaged).

Since asking this question, I've had the opportunity to work on some other Disk ][ drives, and I see now how similar in a lot of ways this Lobo drive is to them, including the IC's. I've ordered new IC's and caps (I need them for a couple other drives anyway... IC's at least), and will start the process of determining if there is a short.

 

amauget's picture
Offline
Last seen: 4 days 22 hours ago
Joined: Jan 3 2011 - 11:34
Posts: 327
This is a short

Indeed, according to your description, there is a short somewhere.

You can try to removed all the IC on the analog card and put the drive back on.

You can also try the cable with another drive, just to be sure.

Offline
Last seen: 6 days 12 hours ago
Joined: Nov 6 2021 - 14:38
Posts: 11
A shorted cap

Well that was easy... a 10uF/25V tantalum cap was dead shorted (the one next to the big blue cap in the image). Replaced it and the drive boots and operates fine now - no IC issues. Ran some read / write / init / speed tests, it's all good. Not bad for a $10 find. The sticker on it said 'fubar' so the seller figured it was only good for parts. Thanks @amauget!

Log in or register to post comments