I had a DC jack failing in my 4 year old thin Samsung laptop and Mark fought through a cold to get it fixed for me on a Sunday afternoon. The fix was technically complex, including having to de-solder and re-solder the replacement part to get it to orient in the proper direction and then to get the jack to sit securely in the laptop. The problem wasn't perfectly fixed (we think the adapter is also going bad) but Mark did a great job getting the repair done and troubleshooting the issue for me. He was very detail oriented in getting the part reconstructed properly. Since it wasn't working totally perfectly (although through no fault of his own, and way better than it was before) he ended up offering to not charge me anything for the repair which took over an hour. He clearly knows what he's doing so I have no problem paying for his skill and time, but this and the reviews here clearly attest to his interest in treating customers well.