Ferrix97
Well-known member
This is the third time that I found a board with this kind of issue, the same fix also works with board that produce low voltages at startup and ramp up as they heat up.
The Board in question is a 630-0560-240V. This is a 240V international board, but the same fix should work on the US ones.
The symptom is complete absence of voltage on the secondary and no (or very little) drive to the switching MOSFET, The problem is usually a bad TDA4605 IC (or optocoupler and its zener diode).
I've seen this issue only on newer boards (where the chip just says Germany, not W Germany like the older ones). The design of the newer revision board is also a little different from the older one (they have at least another diode and capacitor).
If you have low voltages (like a checkerboard pattern with both boards recapped), try heating the chip and the area around it briefly, it should come back up immediately.
I also made a quick schematic around that chip, once I tidy it up I'll upload it.
The Board in question is a 630-0560-240V. This is a 240V international board, but the same fix should work on the US ones.
The symptom is complete absence of voltage on the secondary and no (or very little) drive to the switching MOSFET, The problem is usually a bad TDA4605 IC (or optocoupler and its zener diode).
I've seen this issue only on newer boards (where the chip just says Germany, not W Germany like the older ones). The design of the newer revision board is also a little different from the older one (they have at least another diode and capacitor).
If you have low voltages (like a checkerboard pattern with both boards recapped), try heating the chip and the area around it briefly, it should come back up immediately.
I also made a quick schematic around that chip, once I tidy it up I'll upload it.