OPTOELECTRONICS OS535 REPAIR

 

 

When the Optoelectronics OS535 computer interface is working properly, the screen of the scanner blanks out as the interface takes over operation of the scanner.  Unfortunately, mine stayed in the conventional scanner mode.  The back story is I installed this interface 15 years ago.  Worked great back then.  Life threw me some curveballs, and my scanning hobby was put aside for years.  I recently dug out my gear, and started setting it up again.  This PRO-2042, with the OS535 interface, was my favorite setup. 

I tried a couple of different computers, all the various software options, nothing.  I bought a used PRO-2006 on Ebay (another story), with an OS456 interface.  The scanner I bought was crap, so I put the OS456 in another scanner.  It worked great.  At this point, I was confident there was something seriously wrong with the OS535 since the OS456 was working perfectly.

I contacted Optoelectronics, and they told me what I expected.  The interface was long out of production, and no parts were available.  Worse yet, they said they didn't even have a computer capable of operating it.  I searched the internet, no joy.  It was up to me.  I removed the interface, and gave it a good luck.  I cycled all the DIP switches, and verified their operation with a DVM.  Also checked the DB-9.  All looked good.  The last thing to potentially look at was the microprocessor inside the socket mount.  What you see below is what I discovered!

 

 


There is a special tool to remove these chips from the sockets.  I don't own one, so I carefully pryed on opposite corners with tiny screwdrivers, until it popped out.  As soon as it was free, the corrosion issue was clearly visible.

Wow, that's bad!

The pins were almost shorted together.

By using an acid brush, with the bristles cut short, and a little ethyl alchol, most of the corrosion quickly came off.  I did burnish the pins GENTLY with a small wire brush.

Same technique was used to clean the socket.

With the IC and socket clean, it was re-installed.  The socket and chip both have an index notch, indicating how they go together.

The interface was put back into the scanner.  Now the moment of truth...

With the latest version of PROBE (7.0), my Windows 98 machine (rebuilt Ebay purchase), the interface immediately communicated with the software, and functioned flawlessly once again.  Ultimately, an easy fix, but it was a challenge to find it.  Lots of potential issues can cause communication errors.  Persistance pays off once again.

 

 

 

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Last updated 07/14/14    All rights reserved.