Another NextWave set-top box with bad caps on PSU and logic board
The model is a TDR-3200, and the power supply is electrically identical to the TDR-3100 unit.
See: https://www.badcaps.net/forum/showthread.php?t=3938 for more information.
The TDR-3200 and TDR-3100 PSUs is of the self-oscillating type, with no current sensing resistor on the primary side
.
Since there was no primary side current sensing resistor, the +5V rail did not shut down when C15 (discoloured) was drawing excessive current, causing the failure of electrolytics on the logic board.
All of the Samwha SD Series (85C) capacitors (except for the 400V unit) with low-ESR units along with the following caps on the logic board:
30V rail: CB04 (tuner PCB), C404 (upgraded from 35V to 50V), C451 and C372.
21V rail (unused): C456.
Replacing the above capacitors fixed the problem, and fortunately, the tuner was not damaged by excessive voltage on the 30V rail
.
Should there be a quality recall on certain NextWave set-top boxes (power supply board)? I think so.
See: https://www.badcaps.net/forum/showthread.php?t=3938 for more information.
The TDR-3200 and TDR-3100 PSUs is of the self-oscillating type, with no current sensing resistor on the primary side
.Since there was no primary side current sensing resistor, the +5V rail did not shut down when C15 (discoloured) was drawing excessive current, causing the failure of electrolytics on the logic board.
All of the Samwha SD Series (85C) capacitors (except for the 400V unit) with low-ESR units along with the following caps on the logic board:
30V rail: CB04 (tuner PCB), C404 (upgraded from 35V to 50V), C451 and C372.
21V rail (unused): C456.
Replacing the above capacitors fixed the problem, and fortunately, the tuner was not damaged by excessive voltage on the 30V rail
.Should there be a quality recall on certain NextWave set-top boxes (power supply board)? I think so.
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