Archive for the ‘Repair’ Category

An auction site success – $155 DNA Hybridiser.

February 26, 2012

My cost: $155 (150= auction, 5=box of rivets, only needed one)

Retail cost (new): $2000-4000

I came across a ‘working’ but damanged DNA hybridiser (which is essentially an incubator with optional rotating racks) on an auction site.  The damaged components, according to the seller, were the two parts of the door’s hinge.  I thought that I could fix it (it is just a hinge afterall).  I figured the worse case scenario was that if I couldn’t repair it, I would end up using masking tape and plastic sheeting across the front to seal it.  As is the case with life, things were a bit more complicated when I got the unit.

(Above) Hinge pre-repair.  I set a 1/4″ rivet into the hole and that allowed the door to pivot perfectly.

(Above) Hinge post-repair

(Above) Post-repair bottom hinge.  I neglected to have a picture of the bottom hinge but suffice to say it was in terrible shape.  The bottom hinge is a triangular piece of metal with a protrusion for a pivot point.  When I received it, the plate was bent two different directions.  I was surprised a lab would abuse equipment so badly!  The metal piece was small enough to fit into my vice and so I smashed it flat and reattached it with great success! The feet on the hybridiser are adjustable by rotating them clockwise or counter clockwise.  One of the feet was tilted something like 20-30 degrees.  The fix to this was to remove the foot, use pliers to bend the screw back into a straight position, and reattached the foot.


Going forward from this point things got frustrating.  When I turned the unit on it heated up to maybe two degrees above ambient and I immediately thought I bought a lemon.  I found the manual online and discovered there is a safety reset on the back of the unit that sometimes gets set off when the unit is moved and fortunately this fixed the problem! The second issue was the moving components of the hybridiser (see above circles within plastic brackets) – they didn’t move or make any sound.  On a whim I decided to take off some of the panels to see if maybe I could figure out the issue.  After having every other screw head strip completely and having to use a Dremel to saw off one of the heads I finally got into the unit.  Sure enough the motor that moves the components had fallen apart sometime in the past. Unfortunately I didn’t take pictures of the inner workings because I was tired and frustrated with the screws stripping and mostly I was totally focused on fixing the hybridiser.


On the inside there are two interconnected belt systems that feed onto 1 motor.  The belts had come off their rollers and the motor – connected to the frame only by flexible rubber spacers – was barely attached to the frame.  I used some screw spacers (the kind used to attach PC motherboards to cases) and some long screws and I remounted the motor and reattached the belts.


Now I have a hybridiser worth substantially more than it cost me.  My best guess is the previous owner put up with the damaged hinge up until the point that the inner-workings of the hybridiser broke and they then tried to sell it.  At any rate, I am glad they were unwilling to explore and repair it. As I have posted before, I recommend checking out old lab equipment on auction sites (i.e. eBay) but always be cautious as most sellers have never been to a laboratory before.


Note:  DNA hybridisers circulate heated air with a fan and while they are in essence an incubator, they can’t be used just like a typical incubator because agar plates with bacteria would get cross contaminated easily.  If I ever need to grow something I think I will try putting them into zip-loc bags before putting them into the incubator to avoid this problem.