Author Topic: µCurrent GOLD on Kickstarter (Read 237530 times)

Zucca · « **Reply #450 on:** April 15, 2014, 03:14:39 am »

Quote from: Taucher on April 14, 2014, 10:23:15 pm

Anyhow I'm still a bit wondering what the special trace narrowing near the negative input is ... an emergency fuse I'd guess (there are no replacement specs printed on )

I am still scratching my head for that, it reminds me to a warp zone in Mario Bros...

u271D · « **Reply #451 on:** April 15, 2014, 10:53:05 am »

Finally got around to checking mine today. Not good at all!!!!!!!

Erratic jumpy readings -10mV to +2mV from my 1mA source (DMMCheck Plus calibrated to 1.0003mA)
My Agilent reads the source as 1.000mA (see pic), battery in uCurrent is rayovac CR2032 reading 2.96v, changed battery to GP reading 3.27; and still the same issues.

jancumps · « **Reply #452 on:** April 15, 2014, 11:28:02 am »

I don't see the fulltest setup on the photos.
This is how you set up both tests, right?

u271D · « **Reply #453 on:** April 15, 2014, 01:06:29 pm »

yes your diagram is correct.

HackedFridgeMagnet · « **Reply #454 on:** April 15, 2014, 01:14:48 pm »

do you have two multimeters? That would be the best test.
Measure the current simultaneously in uCurrent and your best meter.

Else put a resistor in series with both tests, say 1 ohm, maybe the problem is that the current source in near it's limit.

u271D · « **Reply #455 on:** April 15, 2014, 02:12:50 pm »

Used two DMM's Agilent hooked up like before reading mV from the Volt output side of the uCurrent.
From DMMCheck I+ to uCurrent+,
uCurrent- to RatShack+,
RatShack- to DMMCheck-

RatShack reads 1.00mA, Agilent mV reading still all over the place-+

Note: I got the 1.00mA reading no mater the position of the uCurrent power switch (off, on, short)

Jay_Diddy_B · « **Reply #456 on:** April 15, 2014, 03:41:27 pm »

Hi,

I had a good look at the photograph of the board.
I suggest that you check the solder connection on R9:

Remember, I am looking at the photograph, not the board

Jay_Diddy_B

jippie · « **Reply #457 on:** April 15, 2014, 05:15:19 pm »

Found mine in the mailbox today. Package looks entirely undamaged, have to test the device later this week. Thanks Dave!

I have the serial number 555, after number 1 probably the best number an electronics nerd could wish for

u271D · « **Reply #458 on:** April 15, 2014, 06:04:56 pm »

In this pic, R9 looks ok.

SeanB · « **Reply #459 on:** April 15, 2014, 06:15:07 pm »

Reflow R1 and clean the switch as well, using a good contact cleaner. and then operate it about 5 times end to end to get the wiping contacts clean. That should help.

There is what looks like a cracked solder joint on R1 sense lead, which would cause this error. If more units have this then it will need attention. Will check my one when it arrives ( hopefully real soon now) in the post.

u271D · « **Reply #460 on:** April 15, 2014, 07:18:03 pm »

My unit number is 47, my understanding is that it was to be built and tested by Dave him self.
It's a bummer that I got a DOA unit, anyone know what the warranty on this thing is?

u271D · « **Reply #461 on:** April 15, 2014, 09:06:48 pm »

Quote

There is what looks like a cracked solder joint on R1 sense lead, which would cause this error. If more units have this then it will need attention. Will check my one when it arrives ( hopefully real soon now) in the post.

Good eye, I've posted a few pic; where you can see it better.

SeanB · « **Reply #462 on:** April 16, 2014, 05:09:27 am »

Dave did point out this on the first batch. This must have been one which was marginal and cracked during transit. AFAIK this issue has been resolved with later production units as they tweaked the process to take care of it.

jancumps · « **Reply #463 on:** April 16, 2014, 05:11:34 am »

Quote from: u271D on April 15, 2014, 09:06:48 pm

Quote
There is what looks like a cracked solder joint on R1 sense lead, which would cause this error. If more units have this then it will need attention. Will check my one when it arrives ( hopefully real soon now) in the post.

Good eye, I've posted a few pic; where you can see it better.

Is it working now?

pts · « **Reply #464 on:** April 16, 2014, 06:06:08 am »

Quote from: SeanB on April 16, 2014, 05:09:27 am

Dave did point out this on the first batch. This must have been one which was marginal and cracked during transit. AFAIK this issue has been resolved with later production units as they tweaked the process to take care of it.

The crack must have been there all time.

Is it due to to little preheating ?

Would a x-ray shown the crack ?

u271D · « **Reply #465 on:** April 16, 2014, 06:53:16 am »

Quote

Is it working now?

No, it's not working. I've hit it twice with the solder gun and still it bounces around.
Is this leaded or lead free solder?

EEVblog · « **Reply #466 on:** April 16, 2014, 10:40:53 am »

Quote from: u271D on April 16, 2014, 06:53:16 am

No, it's not working. I've hit it twice with the solder gun and still it bounces around.
Is this leaded or lead free solder?

Lead free.
Sorry you got a dud

Obviously it would have passed the tests ok.
I can't see anything wrong with the solder joints, but 2D photos aren't very useful.
The only other thing I can think of is that the assembler has reported a few dud switches, so perhaps that would be it. I have not investigated the exact mechanism of the failure yet though.
If you can confirm that then I can ship you some replacement switches. Heck, I'll ship you a replacement board, email me your snail mail address.

u271D · « **Reply #467 on:** April 16, 2014, 01:49:25 pm »

Quote from: EEVblog on April 16, 2014, 10:40:53 am

Quote from: u271D on April 16, 2014, 06:53:16 am
No, it's not working. I've hit it twice with the solder gun and still it bounces around.
Is this leaded or lead free solder?

Lead free.
Sorry you got a dud Obviously it would have passed the tests ok.
I can't see anything wrong with the solder joints, but 2D photos aren't very useful.
The only other thing I can think of is that the assembler has reported a few dud switches, so perhaps that would be it. I have not investigated the exact mechanism of the failure yet though.
If you can confirm that then I can ship you some replacement switches. Heck, I'll ship you a replacement board, email me your snail mail address.

I switch to uA range and my DMM to V (not mV range) and got a reading of .9995 My source is 1.0003mA so:
1.0003mA (+/-)0.05% = uCurrent output of 0.9998V - 1.0008V
Then you add in the meter (+/-)0.05%+5 count you get a range of:
0.9988V - 1.0018V. So if my math is right; in the uA range I am getting a reading within the limits of the uCurrant and my Agilent U1272A DMM. It is just not working right in the mA range.

hammy · « **Reply #468 on:** April 17, 2014, 05:07:27 pm »

Hi

Got my µCurrent today in germany.
Unfortunately I got the tombstone edition!

The banana connector screw is tightened but the circuit board is slightly too thin.

It's #1043. Sent 8/4/14.

Cheers
Hammy

PA0PBZ · « **Reply #469 on:** April 17, 2014, 06:21:55 pm »

Quote from: hammy on April 17, 2014, 05:07:27 pm

Hi

Got my µCurrent today in germany.
Unfortunately I got the tombstone edition!

Wow, look at that led... I'm sure it was not in Dave's functional test bench but still, wow...

SeanB · « **Reply #470 on:** April 17, 2014, 06:58:08 pm »

New note to the test bench person. Check the darn light works along with the other testing.

u271D · « **Reply #471 on:** April 18, 2014, 08:18:45 am »

Dave I sent you a PM a few days ago with my email and shipping address. Is there anything I could do? A specific test I could do? to help you determine what is wrong.

Hyperbyte · « **Reply #472 on:** April 22, 2014, 10:33:23 am »

Hello,

Got my uCurrent today here in Portugal

jamie · « **Reply #473 on:** April 22, 2014, 11:30:22 am »

Mine arrived in Seoul. Fantastic!

Something's up with the mA range though... it's all over the show. nA and uA are good as gold.

No time to debug now, so will fire it up at the weekend weather permitting.

jippie · « **Reply #474 on:** April 22, 2014, 04:04:15 pm »

Mine had a loose input ground terminal and had weird readings. After tightening it, it worked perfectly.


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Author Topic: µCurrent GOLD on Kickstarter (Read 237530 times)

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