Hot Chip

[prezden]

Well I've finished building my Amp6 B but it doesn't work. When I plug it in with a 12V adapter positive polarity the Tripath chip gets really hot even without the jumpers on. When I reverse the polarity of the adapter I get about a 12V reading at the power terminals on J3.
After that I can't get any measurements. Just 0's.
I thought that 1D might be on backwards but it looks the same as in photos posted. It may well be that some of my joints are not soldered well enough. Please have a look at the front and back photos and tell me what i've done wrong.

Cheers- Preston

[prezden]

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[V-bro]

The soldering looks at though it didn't flow very well here and there, especially there right above D12, doesn't that make contact to ground?

One question, what resistance do you measure over especially the speaker outputs and the power input?

------X-max. can be several meters on any driver, too bad it can be done only once...------

[Scratchy]

Hi Prezden, some of the soldering looks like it could be suspect.
If you want to mail it to me on the mainland, I can clean it up and do some additional troubleshooting if required.

You can click on my name to send me an e-mail for my address if you want to go this route.

***If it was easy, everyone would be doing it***

[prezden]

Hi V-bro Thanks for your responce.

I have checked the resistance over the speakers and the power supply and get nothing on either. Here's some other measurements: power supply-12.4V, C2-5.2V, R7-.60V, C5- 12.12V, D1-23om.
I haven't re-soldered any of the joints yet. I did use a different power supply and the Tripath chip got only slightly hot with the jumpers on and not at all with them off.
Any suggestions!

preston

[prezden]

Still hoping to get this amp working with a little help from my friends.

Cheers- Preston

[prezden]

Thanks sratchy and pepolman
I'm going to go over it and re-do quite a bit of the soldering. I think my iron was not hot enough even thou it was set at 350c. I was hoping someone would let me know if I have any of the components soldered on backwards or in the wrong place before I start re-soldering.

Cheers- Preston

[V-bro]

Hi, well that's a very kind offer Scratchy made there! Of course I can understand that it would be nicest to get it to operate yourself, but that's good to fall back on when it won't turn out well..

As far as I can see all the components are on in the correct place and direction, but I only had a quick look (not much time now)...

------X-max. can be several meters on any driver, too bad it can be done only once...------

[Saturnus]

All components are in the correct position and orientation, although I can be completely sure about D6.

Resoldering is definately required. I think about half the solderings are cold solders and the rest are just bad solders.

Make sure you allow time for the solder to "run out" by holding the solder tip on the pad for a second or 2. It's not enough to just melt the solder on the tip. You have to heat up the pad and component and melt the solder on that and not the iron tip.

[Scratchy]

As per Saturnus, the pad is what needs the heat.
The copper traces on this board are twice as thick as most standard PCBs.
Hold the tip of the soldering iron on the pad (not touching the component or lead).
Leave it there for 2 - 3 seconds, then add some flux core solder to the pad.
Once it has flowed on the pad, then move the tip to the component to complete the flow of solder.
Also (as per V-bro) if you don't see smoke then you are not using enough flux.
Without flux, you cannot get a nice clean solder flow and solid joint.
If you are using a small low power soldering iron it may not have enough energy to properly heat the pad.
Using a good 50W iron it takes 3 - 5 seconds to heat some of the pads which are part of the ground plane, as these really soak up the heat.

Have a look at this thread for links to additional soldering tutorials and info:
http://41hz.com/Forums/topic.asp?TOPIC_ID=1978

Keep us informed as to how it's going.

***If it was easy, everyone would be doing it***