I found that making and taping a paper "windtunnel" across the top of the heatsinks caused the fan to draw a larger volume of air directly over the heatsinks and caused them to cool more effectively. I believe I looked into the possibility of using the Nanotec IMT901Q's but either couldn't locate them since they are also an end of life part or there was some very small technical difference on the datasheet. Hope your repair works for you, I got tired of exploding driver ICs.