Camera Repair Blog

Repairing a Wallner CA604 Color Analyzer

•By Admin
Even Lab-Stuff needs Love

Today, we are repairing a Color Analyzer, model Wallner CA 604. I purchased this device for €20, including shipping. The fault description was: "It worked yesterday, but today it doesn't anymore."

Tools:

  • Screwdriver
  • Spanner
  • Soldering Iron

Replacement Parts:

  • 2x 2200µF/16V Nichicon TVX1C222MCD
  • 2x 220µF/16V Nichicon TVX1C221MAD
  • 1x 15µF/63V Nichicon UKL1J150MED
  • optional: 3x 0.015 µF/100V Vishay Polymer

 

First, we open the case. There are three screws on both the left and right sides of the housing, as well as four more on the bottom of the device. On the outer walls, there is a measurement probe and a rotary knob on the right side. These are connected to the circuit boards inside the housing by wires. On the left side, there is the connector for the enlarger.

We desolder these wires directly from the circuit boards.  There's also a fuse on this side, which is worth checking if necessary.

In this case, the problem was with the electrolytic capacitors. They had dried out. There are a total of four large electrolytic capacitors (2x 2200µF/16V and 2x 220µF/16V), as well as one smaller electrolytic capacitor with 10µF/63V located on the back of the circuit board in the upper section of the housing, near the two rotary knobs. These can be easily desoldered, and the solder pads should be cleaned afterward.

To remove the capacitor from the upper circuit board in the housing, we first need to remove this circuit board. To do so, we desolder the pins of the two LEDs.

 

Then, we loosen the rotary knobs. To do this, remove the two caps — one red and one yellow. Next, unscrew the screws and pull off the rotary knobs.

Lastly, there is a retaining ring that needs to be removed using a suitable tool. Once this is done, the circuit board can be freed, and the capacitor can be desoldered.

Note: These are polarized capacitors. The circuit boards are marked to indicate the correct orientation for installation.

I also replaced the three polymer capacitors, since i didnt know how long those usually last.

Finished: