Rigol DG1022 function generator completely dead

[Daveedius]

I recently purchased a function generator from ebay that's completely dead. After doing some probing around on the PSU, I discovered that the bridge rectifier is working properly but the obsolete half-bridge LLC controller (TEA1610T) has a short of 3.5 ohms between the high gate driver pin and its Vdd pin. Unfortunately I don't have a differential probe and I'm not overly familiar with power supplies, so I'm kind of limited in what I can check. But before I order the obsolete chip from China, I have some questions.

1. Any idea what could have caused this?
2. Are there any other chips that should be replaced and/or checked? I was thinking the two mosfets might be good practice but I don't know for sure
3. Does anyone have any schematics for this PSU or a similar one?
4. Does anyone have any information on how these Rigol PSU's work? It seems like there's some signal wires coming from the logic board but I'm not sure

[Gyro]

You should definitely check the mosfets for Drain-Source shorts (probably Gate-Source too). Also check any diodes - including the secondary side rectifiers, even though the PSU should be protected, they would cause an overload.

You might be safer sourcing the replacement TEA1610T from Europe rather than China, it's an NXP / Philips part and you are hopefully less likely to get a fake part!