Service required for HP 9160A Optical Card Reader

[Jurgen Keller]

(01-06-2016 02:15 AM)quantalume Wrote:  Those are nice images! I always enjoy looking at quality, old boards with their gold-plated traces.

You'll find some more nice boards in my Flickr Stream (you have to scroll down a bit).

(01-06-2016 02:15 AM)quantalume Wrote:  The defective board has two inductors which presumably connect to the two adjacent capacitors (you can verify this by following the traces on the back side of the board).

Yes, I've verified that.

(01-06-2016 02:15 AM)quantalume Wrote:  One of the first things to check would be those electrolytic capacitors. They should initially indicate a low ohm value when you connect the meter, which rises over time (seconds) as they charge. If the reading doesn't reach megohms after a short while, then they are likely bad. In fact, it's good practice to replace electrolytics that old even if they seem good. You should unsolder one end of the capacitors when checking them.

I will do that measurements on the weekend, when I've digged out the soldering iron. I'm asking myself what the exact specifications of those capacitors are. I can only see 'USA7143H / 50-25 DC'. I googled around a bit but didn't find anything. Any idea?