Suspicious TH resistors soldering found in branded device

[sasa]

I'm a bit surprised to find this way soldered components in branded PSU (teardown).

Res1 - About 2W resistors, soldered quite high. This board was actually attached to heat sink and leads was dangerously near.
Res2 - Stocking, low value 2W resistors, with no heat shrink, notable oxidized. No space to solder it otherwise, however concern is omitted heat shrink in order to prevent oxidation and possibly sparks or short.

These are  in every source unacceptable ways to solder axial TH components, however I may overlook some rational reason for such solution.

[Rerouter]

Where they sit in a schematic would be far more telling, e.g. if they where in parrellel.

If they where behind a fuse, and on the mains side of an isolation slot, while its not building for longevity (they dont seem discolored so i would say they may have picked the wattage well) Its not negligent,

To me it seems done to manage the power rating well (again, not discoloured), wrapping in heat shrink greatly reduces the effective wattage, Equally the formed leads off the board, that is the norm for hot components, you dont want it damaging the board, The oxidisation looks marginal, I am assuming atleast 1 year old. if you run a resistor hot and the plating reacts with oxygen, it will react.

The only way i would take issue with it is if the resistor body to a lead was less than the required isolation gap, that is a no-no.

[sasa]

Thank you for comment.

The first picture resistors are part of doubler voltage board (2x res + 2x caps, 2x diodes, nothing else). I have actually seen the same board in other models of the same manufacturer with resistors normally soldered.

The second picture ones, probably limit current resistors (second was near) on 3.3V rail. Unfortunately, I have no actual schematic.

[Benta]

It's absolutely acceptable, even preferable to do this. It reduces the operating temperature of the resistors, but more important, it reduces thermal and mechanical stress on the solder joints.

[rsjsouza]

As others have said, components that operate in high temperatures usually benefit from being distanced from the base PCB. This helps with their own thermal dissipation. More often than not I find darkened boards under high power components - especially in single-sided PCBs commonly used in Power Supplies.