Harbinger One LT1054 smoking!!! Help.

[pryde]

Project: harbinger one
9v operation

Need some help here. I made a harbinger one for someone and it worked fine for me and for him for about a week. He contacts me today and says it is "dead"

Opened it up and D6 had come completely unsoldered (on the filter pcb) and was loose in the enclosure 

The LT1054 also had clearly been hot/smoking with shiny spots all over it. I put in another 1N4004 (D6). turned it on and holy crap the LT1054 has smoke rolling off of it !!!

I then removed the filter pcb and installed C22 and D1 on the main board and ran 9v direct thinking it was something with the filter pcb but no luck...it again started smoking.

There are no bad looking solder joints on the bottom?
What should I do here?

Thanks for the help.

[madbean]

It sounds like a short between power and ground. What about without the charge pump installed? What voltages are you getting on the IC socket?

[pryde]

OK. Without the charge pump in here are voltages:

1: 0
2: 8.5v then slowly drains to 0 as I hold the probe on
3: 0
4: 0
5: 0
6: 0
7: 0
8: 9.2v

I see that pin 2 is going to C19 anode. Does that explain the slow drain?

[madbean]

Yeah, I would not worry about C19 draining in that case. If it were doing that with the charge pump installed then that would be a problem. But, we don;'t want to put that original charge pump back in now since it could be faulty.

How about your regulator...what are you using there? Also, is it still wired up in the enclosure, or have you removed it (just wondering if you've eliminated wiring issues as a problem source).

Do you have any other charge pumps on hand? I think your original is toast.

[pryde]

THanks bean.

I put in a new charge pump and it is working like new again with no heat at all 

So, obviously the charge pump failed, not sure why or how. It is possible the guy used a wrong adapter?

Do the LT1054's fail like this for no good reason? I am just wondering what the actual cause might have been if other than a bad chip?

[madbean]

Sure, a wrong adaptor could do it. It can take up to 14v DC, though. Just check your voltages to make sure they are stable.