Failed Capacitors Down DVD Recorders
Article By : Martin Rowe
A capacitor failure in a DVD recorder required replacement. That's what happens with old electronics.
In my home, we tend to keep technology longer than most. One reason is because once you learn how to use something, why change if you don't have to? The other reason is that there's a certain joy in fixing things when most people would replace instead.
Such is the case with two Panasonic DMR-EZ475V DVD/VCR recorders (call them Unit A and Unit B) that we use to record broadcast network shows onto DVD. Figure 1 shows Unit B with the indoor antenna. Unit B's DVD drive wouldn't open, so we had been using only Unit A for a while. When Unit A failed, giving an F60 error code, it was time to investigate.
Figure 1: A single antenna provides the signals to two DVD/VHS recorders through a splitter. An A/B switch routes the recorder's outputs to an analog TV.（Photo by Martin Rowe）
Checking the manual, I found no F60 error code listed. An online search revealed that F60 was a general failure code, usually caused by a failed aluminum electrolytic capacitor. Time to get the screwdrivers.
Removing Unit A's cover revealed numerous electrolytic capacitors. At first glance, none showed the bowed top indicative of a failure. A closer look found one failed capacitor, but it was directly under the bracket holding the DVD drive (Figure 2).
Figure 2: The failed capacitor was under a bracket that held the DVD drive.（Photo by Martin Rowe）
Unlike replacing the surface-mount capacitors in my last repair job, I needed to remove the DVD motherboard, which is mostly power-supply circuits. After removing some 22 screws, four ribbon cables, and connectors for DVD power and a fan, the board was free. The failed capacitor was a 1,200-µF, 6.3-V aluminum electrolytic (Figure 3), one of several capacitors in the DVD power supply. The VHS half of the unit has its own board, but they are connected because a daughterboard (the controller) sits atop the DVD power board.
Figure 3: The failed capacitor: 1,200 µF, 6.3 V.（Photo by Martin Rowe）
Given that Unit B had a failed part, I opened Unit A, which did start normally, for an inspection. No failed capacitors. Nevertheless, I ordered three replacement capacitors online for a grand total of $1.97. See related story, "Small Parts Orders: Shipping Costs Matter", for a commentary on shipping charges. I removed the DVD drives from both units and swapped them. Unit B now worked. One up, one to go.
Replacement capacitors arrived the next day. That evening, I installed one of the new capacitors. Figure 4 shows the new part in place.
Figure 4: The new capacitor is ready to go. （Photo by Martin Rowe）
Before reassembling Unit B, I took a few photos. Figure 5 shows the connectors between the DVD motherboard (left) and the VCR motherboard (right). The RF section is at the far left of the photo. As you can see, there are many more electrolytic capacitors waiting to fail.
Figure 5: The large connector attached to the TV/DVD controller board, removed here to reveal the motherboard components.（Photo by Martin Rowe）
Figure 6 shows the controller board, a daughterboard that sits atop the DVD motherboard. The heart of the recorder is an LSI Logic DMN 8633. Introduced in late 2005, the DVD recorder processor adds an ATSC DTV tuner to the recorder. The chip was developed in advance of the DTV transition in 2009.
Figure 6: The daughter card holds an LSI Logic DMN 8633 HDVT DVD recorder/processor IC.（Photo by Martin Rowe）
With Unit A reassembled, we now have two working recorders. "Management" is happy. The best part: only one leftover screw.