Bob Parker's Blue ESR Meter Assembly & Comments

[Krankshaft]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

Here is a great description on how the circuit works and a schematic:



Your problem is probably in the LED display multiplexing circuit.

Check around Q13 for both correct transistor polarity and the proper value resistors in circuit. Both Q13 and Q12 are responsible for connecting all of the common cathodes on their respective display to ground.

When it's time to addresses display 1 Q12 conducts and IC3 then sends current to the proper segment anodes they then illuminate.

After it's done Q12 shuts off and Q13 comes on IC3 again sends current to the segment anodes. I believe this is how this circuit works. Someone correct me if I'm wrong.

This is done faster than the eye can see so it appears all segments on both displays are lit at once. This allows you to drive two displays with the same 7 segment anode lines and most importantly a single display driver IC.

Q13 is responsible for the second display. Without it the segments on that display can't illuminate even though they are being driven by IC3 on their anodes.

Hopefully the reason it's displaying 0 is because you're shorting the probes because it's supposed to display a - on the left display when they are apart.

[Bob Parker]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

I'm glad there are so many experts on how the circuit works. I'll just sit back and read all the comments - saves me the time of writing.

[Toasty]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

LOL!

I opened mine and compared resistor for resistor to his pics and found no problems.

If it's not a cold joint, could it be 2 mis-placed transistors?

[Krankshaft]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

I see some pretty nasty joints on both the probe wires and the battery clip where the solder didn't properly flow over the stranded wire so there could be some bad joints elsewhere. Unfortunately a piece of test equipment isn't the best place to hone your soldering skills.

The transistors are oriented properly but still check to make sure they are all in the right places.

[bedford_repairs]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

update: here is the solder w flux added and new pictures attached.

Good News first: both displays are now working! thanks a ton for all the information.

I would like to thank everyone for all the input yaull provided, it helps me understand the way the meter functions and what component does what.

1. The meter reads 10 when it is on and i have not seen "-" on the display. ALso the LED on the left has yet to light up.

2. I get an F1 error code when i hold down the power button for the self test. (i went through the trouble shooting guide for this error and still have come up empty handed.)

3. The meter will not power off once it is on unless you hold down the power button for the self test or remove the battery.

I feel like i am allot closer to solving the issues i am having due to everyones input.

Thanks again!

[PCBONEZ]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

If that white dot is indicating polarity then that Zilog IC is in backwards.
Make sure before you go flipping it around.
[That IC is basically the CPU and it IS static sensitive.]
.

[Agent24]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

If that white dot is indicating polarity then that Zilog IC is in backwards.
Make sure before you go flipping it around.
[That IC is basically the CPU and it IS static sensitive.]
.

That's what I thought too when I first saw his photos, but the notch tells a different story.

I think if it was in backwards he wouldn't get any kind of display at all, except maybe a (rather small) fireworks display?

[Bob Parker]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

IC2 is NOT around the wrong way. The fact that it's working proves it. If you reverse it, it will be destroyed and you'll make things a lot worse.

Now I'll sit back and watch again. I suppose I shouldn't be surprised that the last person who's taken seriously is the person who actually designed the circuit and the micro firmware.

[cmj21973]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

1. make sure the test leads are not touching before turning the meter on.
2. turn meter on should show (-) in DISP1
3. touch test leads together (short) to zero the meter out

if leads are clipped together, before turning meter on, it shows (-) briefly then .xx when the meter is turned on.

[bedford_repairs]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

Your pictures are of...
Leads shorted together?
Leads not shorted?

Swap the displays, verify operation of other.
Decimal point LED in correctly? Does it even flash when leads are shorted?
Do you get the ( - ) sign in left display without leads shorted?

Toast

When I short the leads out I get ".00".
Not to sure why it is doing that. Thanks for the reply
To make sure we are clear.

When I power on the unit I get "-" on the disp1 then ".10". Then if I press the power button again I get ".00". If I touch or short the leads nothing happens. Stays at ".00".

The picture is without the leads touching.

[PCBONEZ]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

I have a MKII but I think yours is the same in this....
The routine is to turn it on.
Then short the leads and push the on-off button again to zero the meter w/leads in circuit.
Then measure something.
.

[Toasty]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

IC2 is NOT around the wrong way. The fact that it's working proves it. If you reverse it, it will be destroyed and you'll make things a lot worse.

Now I'll sit back and watch again. I suppose I shouldn't be surprised that the last person who's taken seriously is the person who actually designed the circuit and the micro firmware.

What's with the attitude? Everyone's just trying to help...? Especially the first time you said it when the post before it said " I believe this is how this circuit works. Someone correct me if I'm wrong."



* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Back on topic-

".00" in the display, with the leads shorted, could be correct before calibration. Staying at .00 after the leads are un-shorted, is NOT correct.

Going through the "motions" with mine, I offer these observations of operation:
- press power button, DISP2 typically blinks (either a "0" or "-") and the center decimal point *may* flash and go off, then DISP1 will show "-"
- short leads together, unit will show ".0X" where X is any number and is actually indicating the resistance in the test leads.
- with the leads still together, pressing the power button will zero the unit and the display will show ".00"
- with the leads separated, the display shows "-" in DISP1
- "-" continues for several minutes if unused then auto-shutoff

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

With everything "appearing" to be in place correctly, some problems I can think of are:

1) You still have a bad joint/connection as Bob said in the beginning
2) Pull and re-seat those IC's and the displays in their sockets. Hopefully you pulled them out before resoldering the pins....?
3) Inspect every transistor and make sure you did not swap a 3904 and 3906 somewhere.
4) Verify the regulator is delivering 5v
5) Could the crystal be damaged/not working, killing the multiplexing?

Finally-
Have you performed the diagnostic procedure in the troubleshooting section found on Page 11 "It does not work, now what?"

You need to remove the battery and supply 6.2v to 6.8v instead. Also calls for shorting out R30 (100Ω - next to big cap). There are a number of diagnostic codes that you can refer to and post up here. Perhaps that will narrow this down.

Keep Fightin'!
Toast

[Quasar]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

Did this ever get working? I was thinking of buying the kit, but maybe I'll go with the factory built one instead. Or should I consider another brand if these are that much trouble?

[PCBONEZ]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

Most of the time there isn't a problem with the kit.

[Agent24]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

I built one, worked first time. If you know how to build a kit properly there will be no problem.

[Krankshaft]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

First time worked perfectly here too.

A great majority of the time a kit not working properly is the result of either improper component location or poor solder joints.

[franko]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

To Bob Parker :

Thanks for designing the ESR meter. I just finished building one and I expect it to be quite handy going forward. I did have a couple of hiccups during construction, though, and this feedback might be useful.

First, in the kit of parts from Anatek, I received a larger-size 200 ohm potentiometer for VR2. The lead frames on this device were too large for the hole diameter you have on the printed circuit board -- a hole diameter I suspect you chose for the smaller-size pot. I got one of those smaller-size pots for the other pot, and it fit perfectly. So if you revise the board layout anytime soon, I suggest you get some of these larger pots and use measuring calipers to help choose a slightly bigger hole size -- one that will work for both size pots.

Second, you might wonder what troubles this created. Well, this is where it gets a bit interesting. I noticed upon powering up that there was very little variation in the readings. I could zero okay, but got readings in the 50 range under all other circumstances. The big clue was when I twisted VR2, it made no difference in the reading. So I guessed I was looking an open circuit. I did go through the diagnostic, which gave me a reading of F6, and I checked the devices suggested in the assembly manual and found them all in good shape. So I came back to the open-circuit behavior and verified I did have an open-circuit with a multimeter. I then desoldered VR2 (it didn't really solder well since the leads were so big), inserted some leftover leads from other components through the holes, and soldered VR2 to them on the top side. Then the diagnostic passed. So it looks like another symptom you might add to the docs for the future would be to check to see if VR2 is open-circuited -- particularly until Anatek begins shipping a revised PCB.

[stopher]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

MY PROJECT EXPERIENCE

BACKGROUND my 16 year old son and i took this on as a project. we plan on using it to fix our Samsung TV power issue.(likely capacitors).
i am a 'noobie++' (i have education, experience, knowledge, etc. but not frequent hobbiest). My son's 3rd electronics solder problem. He helped me with the Sony projection TV convergence circuit 2x18pt inline motherboard chip replacements and picofuses...3 times over 4 years. (SONY SUCKS). looks like Samsung does too...bad caps.

FEEDBACK
we had erred and swapped 200R and 200K resistors and had to troubleshoot and rework. a classic problem apparently.
(C7) 33nF 100WV received was tiny yellow, not large red as in photos and tiny - terribly difficult to read. after finishing all parts, took a leap of faith on that as it was the last cap.
polarity on one transiever backwards....oops.

RECOMMENDATION
wear magnifying visor or costco 200x glasses.
emphasize solder practice first.
emphasize tiny solder tip and solder practices of vertical withdrawal of tip.
cross referencing parts, devices, bags, codes...ok, but
emphasize practice of 5 parts at a time - install-solder
refer to a capacitor "best practices" guideline to replace capacitors with higher voltages, but same Farads, when replacing

TIME 2 hours for a noobie (30 min for a sharpie)


Thanks. Worth saving a few bucks, had experience with son, that can save on cheaply and easily fixing lots of crap appliances.

[MDOC]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

MY PROJECT EXPERIENCE




cross referencing parts, devices, bags, codes...ok, but

cross referencing bags?

[Moody]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

hi can someone show me a completed circuit board of the blue esr meter when assembled and working