That sounds great. I'll be in China/Hong Kong for holiday and it seems like I could fix some broken devices there :)
Keep your valuables hidden, keep a look out for suspicious people and look them in the eye.
Here's my 2c for places to go in HK: > Sham Shui Po > Mong Kok / Yau Ma Tei > Wan Chai Computer Center > 298 / 188 Hennessy Road
If you go to any of the places above, don't be afraid to bargain. If you pay cash you'll be well served by doing a quick survey of a few stores - there's usually a clear price and you should go below it. You won't have to worry about any language issues, too.