Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › the Pimeta-V2 thread
New Posts  All Forums:Forum Nav:

the Pimeta-V2 thread - Page 36

post #526 of 562

I love molex connectors. I haven't shelled out for Tangent's tool yet, I use an inexpensive crimp tool made for beading and jewelry making. (A lot of beading tools cross over nicely for electronics, especially the wire turning stuff like the round nose pliers.)  It's about $6-$8 and is available at most beading stores, Jo-Ann, Michaels, I think even Wal-Mart.

 

It's called a Beadalon Bead Crimping tool:

http://www.amazon.com/gp/product/B00114OY06/
 

It requires practice and some finesse, but I'm sure that's true of the $45 Molex WM9999-ND crimper.

 

It might not work for you, it does take a few tries, and I do plan to get the Molex crimper soonish. But the beadalon thing has done the job for me for quite a while. I do put a tiny drop of solder in there just to make sure, but that's just a weird thing I do and would do no matter what.

 

Good luck and if anyone picks one up, I'm very curious to know how well it works for others.

 

Cheers!

-s


Edited by saraengelstad - 2/11/13 at 5:39am
post #527 of 562
Quote:
Originally Posted by MisterX View Post

I like GC/Waldom/Molex # W-HT-1921-P for KK pins but to each their own.

 

Yes, that looks like a good choice.

 

I suppose I skipped over it because I already have more wire strippers than I know what to do with, and as a rule, I tend to prefer the T-stripper sort over that kind, so having everything in one tool doesn't really appeal.

 

Still, it's hard to argue with $20.

 

The official Molex tool has more sizing choices, but the two your tool provides probably suffice for most jobs. Worst case, you get a half-crimp and then have to crush it a little with needle-noses.

 

Quote:
Maybe actual pictures of the top and bottom of the PCB would help?

 

Heh. I've just been walking over to Tangentsoft Intergalactic Headquarters (a cabinet in my front room) and grabbing a PCB to look at. :)

 

I'll keep it in mind. It takes a bit of time to set up a proper shoot.

 

Quote:
Originally Posted by tent View Post

The green caps are very good caps for the C6 positions, Im using 12pf

 

Never mind, I see what you did now. I was referring to these green "capacitors":

 

 

 

I see now that they must be your actual R4s, not ceramics paralleled across the thru-holes I assumed were on the other side. I didn't cross-reference both top and bottom pictures against each other before commenting.

 

Quote:
Originally Posted by saraengelstad View Post

It requires practice and some finesse, but I'm sure that's true of the $45 Molex WM9999-ND crimper.

 

On the contrary, the proper crimp tool is very quick to use. You just place the terminal in the slot, line up the stripped wire, squeeze, done. The hardest part is making sure not to tip your hand, thereby dropping the terminal out of the crimper's jaws, and that's no harder than learning how not to tip a hand of cards.

 

By the way, Mouser only wants $33 for that tool.


Edited by tangent - 2/11/13 at 9:24am
post #528 of 562
Quote:

On the contrary, the proper crimp tool is very quick to use. You just place the terminal in the slot, line up the stripped wire, squeeze, done. The hardest part is making sure not to tip your hand, thereby dropping the terminal out of the crimper's jaws, and that's no harder than learning how not to tip a hand of cards.

 

By the way, Mouser only wants $33 for that tool.

 

 

 

OK, you might have sold me. Do they work well, anyone have any idea, on FCI terminals?

I really like the dobox connectors, I think they look a lot sharper.

 

post #529 of 562

No problem.. I also did not understand you were referring to those as per "green caps".. ;)

anyway suggestions for next steps? should I dismantle and start over from the beginning? I would maybe try to:

- susbtitute the split rail ic2

- swap the PSU caps.. they were some samsung caps I found in some compoents bin.. could be they (or one of them) is somehow "old"?

- any other idea...

 

tent:wq

post #530 of 562
Quote:
Originally Posted by tent View Post

- any other idea...

 

I'm out. Need fresh data.

post #531 of 562

no success so far.. I keep seeing this "unbalanced" voltages about everywhere on the board.. across C4+ the 2.55V and across C4- 5.65V, etc..  is there some specific measurement I could do to try to isolate the component or area where the issue could be? (for example if some cap or some ic, etc) Did someone else also have ever had such strange "unbalance" ever?

 

tent:wq
 

post #532 of 562

At this point, if it were me doing the work, I think I'd remove the buffers and the op-amps, then re-do the power supply tests.

 

If the power supply is fine with the amplifier ICs removed, clearly one is broken, or the problem is due to the feedback loop.

 

If the power supply remains imbalanced, I'd replace the TLE2426, then re-test, expecting it to be fixed now,

post #533 of 562

Hello,

 I was out of town but finally back.. actually without good news: without ICs the issue was still there, so I ordered and replaced the TLE2426.. bit without success, everything still unbalanced.. :( what could it be?? :(

 

 

tent:wq
 

post #534 of 562

Measuring the resistance between the V+, IG and V-, IG pads may help point you in the right direction.....

post #535 of 562
Quote:
Originally Posted by MisterX View Post

Measuring the resistance between the V+, IG and V-, IG pads may help point you in the right direction.....

 

Yes, with the power switch turned off. It's looking like some kind of partial short circuit.

post #536 of 562

uhm... interesting.. I read 684ohm between both chip's V- and IG and somehow infinite resistance between V+ and IG (the ohmmeter counts up till out of scale..)

I can try to make some better high res shots of the board if needed or the short could be in some cap or else (for instance I decided to use some tantalum cap C4+ and C4- but not sure of the origin of those tants.. maybe too old.. )?

 

tent:wq
 


Edited by tent - 3/3/13 at 12:59pm
post #537 of 562

I was just looking at your pictures again, tent, and I think I see the problem: you've shorted C4, haven't you? If so, time to re-read the docs.

 

Not only should that jumper not be there, the cap isn't optional when you install C3 and C5, as you have.

post #538 of 562

actually I just wrote I've used two black tantalum caps in C+ and C- (22uF, 16V, with black drop ceramic coating) but I'm starting to have some suspect those are some old tants that might somehow have issues? could I test that? or should I simply try to substitute them? But definitely I have not shorted the C4 position, but the picture isn't clear enough indeed.. ;)

 

tent:wq
 

post #539 of 562

Is C4- installed the correct way around?

A backwards tantalum capacitor seems like a fitting explanation for the 684 ohm reading between V- and IG...

post #540 of 562

uhm.. also this seems to be a good point!

But first of all let's say I interpreted the writings on the PCB like that: C4- writing means the - leg of the cap should go in the hole nearest to the - sign of the C4- writing, correct? I interpreted the opposite for the other tant: the - leg of the cap needs to go on the opposite/farest hole of the + of the C4+ writing, is this also correct?

 

tent:wq
 

New Posts  All Forums:Forum Nav:
  Return Home
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › the Pimeta-V2 thread