Wednesday, June 13, 2012

Testo 500 Guages Fix.

Testo 500
I love my Testo 500 Refrigeration Analyzer to the point that I swear by it for accurate, reliable, and timely system diagnosis. I can find problems quickly and charge quickly and accurately. For something technically audacious as a set of digital gauges, they've been durable, more so than set of dial ones. The only thing I've had to replace was a temperature clamp and a couple sets of batteries in the two years I've used them. Not bad at all, even at $350 for the set.

One thing I do find fault with is that when they go out of calibration, they need to go back to the factory in Germany for repair. This involves shipping costs to and from same to Michigan USA as well as the cost to fix them. The one thing that my supplier was sure of was that they didn't know what the cost was going to be; for any of it. As a technician who depends on these tools, waiting 14 days and spending the money to ship these to Europe is something best avoided. "I don't know" is a factor that can range from a few dollars to well in excess of the price of new equipment. This is not something I can chance right now. I know the set got wet a few days ago and  got a hell of a lot of oil through it on a tune up on Monday. Here's what I did to fix it, and if it quits, I'll tell you that in an updated article.

As for water, these gauges have plugs where the clamp leads go in, but I lost one of mine and this is how the water got in. To make matters worse, I couldn't zero in the pressures and the screen had a bit of a watermark to it. In fact it read "uuuuuuu." Be very careful when taking apart an electronic device and ground yourself out beforehand. If you don't you could fry the components with static electricity. Do not force parts together, or touch the surfaces of the board with your bare hands. Use rubbing alcohol or electronics cleaner on all parts. Do not use soap, water, or other cleaners inside the unit or you will wreck it. You will need a Phillips head screwdriver, a small pry tool, a hair dryer (DO NOT USE A HEAT GUN!) a syringe with no needle and some rubbing (Isopropyl) alcohol. Remove the battery door and the batteries and then you can remove the six screws holding the back on the unit. The circuit board comes out next, and you need to unplug the two Molex connectors to the manifold. You can use a pry tool to unclip the pins holding the knobs to the manifold and remove that from the case.

Push the touch pad from the case, clean the insides out with rubbing alcohol and let air dry. Also flush out any oil from the manifold with the syringe and said alcohol and let air dry. To remove the watermark from the display and dry the board, use the hair dryer on a low setting until the display turns black and then stop. You put the back of the case on the board and reinstall the batteries temporarily to turn the unit on and check if the watermark is gone. If not, take it back apart and heat it again, but if it doesn't go away after that and it works, leave it alone. Put the case back together and try out the buttons. You should be able to zero it out and go through all the functions without fighting it and the sight glass should be clean. Hopefully saved a few hundred bucks on equipment. Maranatha!

1 comment:

Walter Grace said...

The gauges are still working fine. FG