I have been using my InWin H Frame small form factor desktop computer for more than 5 years now. Some reflections:

• Using the AMD APU, the graphics is decent, but by no means high performance, so playing games have always been less satisfying because the frame rates are low even at low quality settings.
• The built-in 180W power supply is not powerful enough to fully utilize the APU's performance. If I set the TDP to 65W or 95W, and run heavy processing (games), then I get sudden black screen, and I attribute that to the power supply not able to keep up with the demand during some peak load spikes. I have been running the APU with TDP set to 45W.
• Recently within the last few months, I am starting to experience sudden black screens even with TDP set to 45W. I suspect the power supply may be aging and not able to provide as much power as it used to.

The integrated power supply is a In Win IP-AD180-2, which has a spec of 10A max for the 12V rail. Previously I have also tried using the PicoPSU-160-XT with a 8A full load and 15A peak load rating, but it also did not seem to provide enough power during full load.

In Win built-in 180W power supply 

PicoPSU 160 XT

Recently I came across another DC-ATX product from HDPLEX and they have a 200W and a 400W version of a DC to ATX power supply. The 200W has a 15A rating on the 12V rail, and the 400W has a 35A rating (divided into two groups). These devices are paired with a AC-DC converter that outputs 19V DC. The 200W unit might be worth a try as a replacement of the built-in power supply.