And it looks like my NewEgg Cooler-master 120 just arrived this morning, so I should have something to play with today.

This will be fun.

C

There is a fair bit of extra pad, might fit. Worth a try...

How about the HF? The things cost 5 bucks here in the US. What's with the high euro price?

C

I think the problem is the power supplies have a capacitor going from one of the two AC pins to the DC neutral. This can be very helpful for increasing the power factor, but if the capacitor were to short then it would conduct one of the 240 volt legs to the negative line on the jally.

This 120 volts would not be a problem except for the fact that it goes to the ground of the USB line. Which then goes to your computer. If your computer's USB jacket is grounded, then 120 volts goes from wall through broken capacitor through jally through USB cable to computer to frame ground back to the utility. Boom.

Speaking of which, one should be able to replace this chip with an LQFP 48 pin one which would be a hell of a lot easier to solder. Recommended for followup.

C

Update. Sunday night, still running, no problems. Glad this works.

C

Quick heat question: My Chili is expected tomorrow, but my heat sink is not coming till Tuesday. Would it be suicide to put an older IBM X series big copper heat sink on top of it and try it out? Will the chips burn out, or take damage?

C

Oh I did also chat with that Ebay seller; he's fixing the auction so he can do international. I'd say give it a go.

C

Well, that makes two failures of trying to re-flow chips on a board that came off other boards in "odd" condition. I clean the chips, remove the solder with an iron at 750f, flux, and desolder braid, put it on the board, center, and give it 350f low temps and 450c temps for 2 minutes. Same as the other chips which go on fine.

Fail. Tried adding flux and another 2 mins, fail. Drat. Fortunately this is on the junky jally so I wouldn't mind if it were trashed. But it did not work :-)

I'll debate just buying chips over trying to continue adding these. They could have been wrecked by the previous owner, but to be honest these chips seem to take a lot of heat and work. I guess I could spend $70 for a reballing kit, but the value is kind of eh.

I'll wait for the new jallies to come in before trying to put on my last 5 chips. Should be Christmas eve, I wonder if I can put up a big sign saying "JUST LEAVE IT WITHOUT A SIGNATURE DAMNIT!" or something like that :-)

C

Maybe. I've fixed a few jallies pretty simple actually, pm me with the problem.

C

By the way, you're also forgetting about power factor. Crappy power supplies have a PF of .5 or so which means you're pulling a lot more volt-amps than if you had a better supply with a .8 or .9 PF rating. volt-amps are not quite the same thing as watts, and volt-amps are what generate heat in lines.

So.... Make sure you get good power supplies. The crappy BFL supplies have a PF of only .6, my Corsair is over .9. Oh and if you can, run your supplies on 240 volts, more efficient. Actually if you can get 3 phase and run 208 volts to your stuff.

C

*snort*

Actually I think part of the spate of recent jally-usb issues is related to BFL pointing the fan *down* for some reason. If you have the sides off it's a good idea, but with them on what happens is that hot air washes over the FTDI232 chip, which is the fastest way (aside from a massive ground fault) to kill the chip.

On a Chili note, I have one of those super big AL sinks and a $50 water cooling block coming on Tuesday with my new board. Would it be better to put the water block on the top or bottom of the board, and can one mount the fan heat sink to the board without a pad (just thermal grease)?

C

Honest answer: I use pads on my jallies that have the old and new style chips (the newer ones are lower profile) on the new chips only. On the old ones I use a dab of Radio Shack $2.00 thermal grease.

Where I win is putting thermal grease on the bottom of the jally, then either putting the bottom plate on or another heat sink. Do not underestimate how much heat you can draw off the bottom of these things.

C

Jesus fucking Christ. You know, I think given enough time I could fix a rainy day.

Summary: This burned out jally with no USB response is fully operational. What happens is the USB FTDI232 chip burns out, and you have to replace it. For someone who has done Xbox repair this should not be hard. For someone like me who has done BGA and SMD work but not these stupid QQ chips it's a screaming pain-learning curve.

Removed the old chip with air tools at 450c with a 350F preheater under the board. Came off no problem. Put new chip on with same temps (2 mins at 450c) like a BGA cpu. Burned the fucking chip out.

Pulled it, put another chip on, 275c for 60 seconds with a 350f preheater (I buy 3 for shit like this). Chip goes on, comes up as a BITFORCE, all "J's" when I try to run diagnostics. Um, I think I need to reflow. Added solder balls, melted with the iron, cursed a lot, hit it with 300c heat for 60 seconds around the sides of the chip, and...

It COMES UP! It's a 6gh jally. It sucks, but it does run.

So I fire up the BFGMiner and it immediately screams that the chip is at 130C. Fuck again. Check the diags, S2 is at 130, S1 is at 30c. Um... Pull the heat sink. Note this one had a loose heat sink from the factory and it was banging around. Found that S2 was ripped off the board by aformentioned sink, and the pads were gone too.

Time for a lobotomy. So I went into the code, changed S2's AD channel to be S1 so the code will always read the working S1, put in a comment saying I know this sucks, but I had no choice due to bad assembly, compiled it, loaded it, attached the fan and...

It's hashing away at 6gh now. So it looks like a blown European Jally can be fixed with a $3.00 part, and a person who knows how to sweat chips on and off the board.

Go now, everyone. Fix your jallies, hash, and bring the difficulty up. I have completed this task, and if it wasn't 4am I'd say it's Miller time.

Fuck it, it's always Miller time. Off to get a cold one then to bed.

If you can, please.

C

Well, I boosted a friend's jally to 4 chips. Here is my thoughts:

3 chips: Warm, from 38 to 50+. Do-able
4 chips: Holy crap it's *HOT*. 80c, throttling with my BFGminer.

I now have an old AL heat sink on the bottom plate (secured with thermal grease) and a fan on it from the side, will see if it holds. But running a jally with 4 chips and no bottom sink is not a good idea IMO.

I also think I need to take the top off this thing. But 15+gh, no problem with the chips. Flux on the bottom of chip and on board, thin coat, set the chip square, review with a loupe, 350F pre-heat for 10 mins, then 450c at low air flow at .25 inches off the chip for 2 minutes. Done and done.

Edit: Taking the top off and letting the fan breathe makes the difference.

C

Um I forgot. However I put a new 232 chip on, nothing. Interesting. However a question: Do you see ground on any of the 4 USB pins?

Oh and 4 chip jallies with AL heat sinks? HOT AS HELL! Put sinks on the bottom like now.

C

Well, let's think: What could cause a short? Your chips!

If you don't want to take them off, then get a light, put it on one side of one of your chips, and look through with a loupe or glass on the other side. See if all the balls are perfect? Then do the other axis.

Try removing your chips. Yes, you're gonna reball. Let's go halfsies on a reballing stensil and table, screw it.

Myself, I have a vial of balls from ebay, since there are only so many of the things and I have watch tools I am going to try putting them all on and see if I can make it go. Line them up, then low low low air and heat to see if I can melt them. If it doesn't work I'll get a stencil.

As for the first paragraph, eh I work with heat pads which can make up the height loss. I'll try one on the dead UK board once I bring it back online.

C

That's odd. I can email him myself and ask if he will ship to Poland and Canada. This is a big world of course.

C

That's about it. Oddly enough my 20gh jally can crowbar my 300 watt cheap-ass ATX supply as well, which is why I am recommending using 500 watt corsairs for clocked units.

*snort* Pretty much. My next three jallies are coming with a 3 wire PCIX cord from BFL, but yeah I wired my old jally supply into a beautiful 30 watt halogen gooseneck lamp on my desk. The power supply for it died years ago and I always wondered what I could power it with. What's the jally supply gonna do; set fire to the bulb?

:-)

Who, Lent? Send him a private message, he seems to be a good egg.

C