Hot MOSFET BFL Jalapeno Fully Cooled

[natbyte]

I modded my BFL Jalapeno for cooler running by removing the case and flipping the fan over so the air is now pushed down over the main heatsink. taking a laser thermometer to all the chips on the circiut board, and measuring temps, the hottest chips on the board were the MOSFETs and the ADP1850 and surrounding capacitors, these were all pushing over 50 degrees C, the MOSFETs are 65+ degrees C. My simple but effective mod, using forged copper heat sinks have lowered temps significantly. Over the past 24 hours I seem to have stable hasing at 5.6Gh/s now, it used to vary significantly I am unsure if the cooling assists with the more stable hashing but it certainly seems so thus far.

[Photon939]

I wonder if my unit has the hot mosfets or not, could you get the part numbers for the mosfets on your unit?

I removed mine from the case and just installed a better fan blowing down - the mosfets are only slightly warm to the touch (maybe 30-32C?) without any heatsinks

[natbyte]

If they are warm to the touch you will have the cool version, if they are too hot to hold your finger on for a second or two you have the hot version the two banks of MOSFETs were both about 65 degress C.

[Photon939]

Yes but I don't know if that is due to my increased airflow or not.

Verifying part numbers will enable others to check what theirs has with 100% certainty

[natbyte]

Sadly its no longer easy for me to remove the heat sinks, I used a 3M thermal tape to affix the heat sinks in place and this has a very high adhesion and is pretty tricky to remove, I wanted the heat sinks to be safe and secure should I decide to recase the unit and move it without having to worry about one of the heatsinks coming loose inside and causing a short, when I power it back on.

[Edit]
I managed to find a close up before I added the heat sinks for the MOSFETs

Hope the image helps

[Photon939]

https://dl.dropboxusercontent.com/u/1181169/P1010171.jpg

Looks like mine has two different types of mosfets, but the one matches the part number in your photo. Looks like I have the hot mosfets

[whitefeather]

I modded my BFL Jalapeno for cooler running by removing the case and flipping the fan over so the air is now pushed down over the main heatsink. taking a laser thermometer to all the chips on the circiut board, and measuring temps, the hottest chips on the board were the MOSFETs and the ADP1850 and surrounding capacitors, these were all pushing over 50 degrees C, the MOSFETs are 65+ degrees C. My simple but effective mod, using forged copper heat sinks have lowered temps significantly. Over the past 24 hours I seem to have stable hasing at 5.6Gh/s now, it used to vary significantly I am unsure if the cooling assists with the more stable hashing but it certainly seems so thus far.

Any advice where I can get those copper heat sinks? Part Numbers? Thanks!

[tacotime]

You should look up the MOSFETs they use and see if that's actually anywhere near the temperature limit, as many MOSFETs function perfectly normal up to 105C.

[natbyte]

The main board states a max temp of 83 Degrees C, I supect any hotter and the ASICs will reduce hasing to prevent overheating, I have just seen over on the BFL forum they have stated its beneficial to cool the MOSFETs if you have the hot version. Stability has improved since I added the heat sinks, even if its a placebo.

I can at least know I am prolonging the life of the hardware by running it cooler , with this setup I run @ sub 32 degrees C, many screen shots I see for the jalapeno show temps are in the 42 - 60 degrees C range. The highest I've seen is 67 degrees C.

The heat sinks are forged copper, actually used for a Raspberry Pi however they can be modded to fit these chips easily. See here Forged Copper Raspberry Pi heatsinks