Silverdog PIC meter problems-help?

[SVEN1]

Bought a PIC cap., induct. meter kit from Silverdog.
Cap. meter features works fine.
Problem is Inductance meter feature will not work.
I took this PCB apart twice, checked everything, even used new caps and resistors, wiring was checked over and over, I cannot find the problem.

Inductance test with short stays at 0--AWAITING TIMING

What do you think of this meter on ebay?
http://www.ebay.com/itm/USA-LCR-RCL-...item5d32776c67

[Jerry]

Just a quick observation without knowing anything about this meter. Try using a larger inductance. Looks like you have just a jumper wire in the picture.

Jerry

[homefire]

Yep, your trying to test something out of the limits of the meter.

[SVEN1]

But, per instructions for this meter:

To test the LC oscillator, switch S2 to
position 1 (inductance) and clip the probes
to each other (as a short circuit). In this
configuration inductor L1 completes the
feedback circuit for IC3a, which oscillates
accordingly.
Adjust preset VR2 until the oscillation
rate appears stable, as indicated by the frequency
value shown on screen line 1. The
setting will be obvious if an oscilloscope is
used. If a scope is not available, try VR2 at
various wiper settings and chose the best –
it is not critical. In the prototype the author
set the wiper for approximately three-quarters
clockwise rotation (about 7k5).
Again the frequency and calculated
results are shown on the upper and lower
lines of the screen. In the prototype typical
un-nulled values are 468608Hz and
11.492H. Pressing “null” switch S3 the
inductance value should read 0·000uH
Now clip an inductor of, say, 10H
between the probes. A typical display
might then be 342348Hz, 9·969uH. In this
case showing that the external inductor is
pretty close to its marked value.
As with the capacitance mode, the pulse
width assessment technique is used when
the monitored frequency is below a certain
value, 16384Hz for inductors. Again the
frequency value is shown with three decimal
places.
On the normal frequency counting range,
values less than 100H are displayed with
a “uH” suffix, otherwise they are shown in
millihenries (mH), i.e. 100.801H would
be displayed as 0·100801mH.
Values obtained using the pulse width
technique are displayed in henries, with a
suffix of “H”, for example 7.305H.
Be patient when monitoring higher values
of inductance, for the same reason as
for larger values of capacitance

[homefire]

I've not looked at the circuit.

It stands to reason you have a open on the Osc?

Corrupted Code on the PIC?

[bernte_one]

hello sven

i have that 4070L multimeter longer than 2 years
works good
but testing tips that are delivered with are crap
so buy the meter and separate testing tips (maybe also a pair with croco clamps)
and you have a good tool

regards

[SVEN1]

Thanks ordered one, 4070L multimeter.
Thanks

[Rov]

Hi SVEN1,enyou your new 4070L Chinese meter order,But please dont rely on its accuracy!
I have several LC meter imports via China an Other,for homebuilds coils etc.
If you do several or many home workshop checks for your coils.Please do a comparison check amongst your readings amongts meters.Errors are prevelant!
.I have several Meter checks done.Via MIT. Certifiy for compliance and at Institute Cost$$ and most dont meet the Spec.? for LC.
It concerns me often,hence the $$ compliance Test,compliance, and Accuracy tests from MIT.Australia.
I do my LC checks via a suite of Meters.
The best and with Mit. Testing at my cost $$ was the Silicon Chip Design Meter.
from Altronics as Kit was K2533LC meter kit.
A Short and Well built Bananna Plug/Aligator clip prob set was required for all! not just the supply test clips with any meter?
Regards Rov.

[SVEN1]

Hi SVEN1,enyou your new 4070L Chinese meter order,But please dont rely on its accuracy!
I have several LC meter imports via China an Other,for homebuilds coils etc.
If you do several or many home workshop checks for your coils.Please do a comparison check amongst your readings amongts meters.Errors are prevelant!
.I have several Meter checks done.Via MIT. Certifiy for compliance and at Institute Cost$$ and most dont meet the Spec.? for LC.
It concerns me often,hence the $$ compliance Test,compliance, and Accuracy tests from MIT.Australia.
I do my LC checks via a suite of Meters.
The best and with Mit. Testing at my cost $$ was the Silicon Chip Design Meter.
from Altronics as Kit was K2533LC meter kit.
A Short and Well built Bananna Plug/Aligator clip prob set was required for all! not just the supply test clips with any meter?
Regards Rov.

Thanks,
I have a co-worker who has been an electronics tech and teacher for 30 years, I'll let him take the 4070 home and check it's accuracy with what he owns.

[Rukbat]

Inductance test with short stays at 0--AWAITING TIMING

Check the inductor oscillator around IC3a, L1, VR2, C5a, C5b, C6a and C6b. With the probes shorted (and the switch at "inductance") it should be producing a signal at pin 11 of the IC. If it isn't you probably have a little solder short somewhere or a bad component.