Last Gaussmeter Problem? (solved!)

[-Elepro-]

ok.. if you have tension, your pcb seems ok and display show a well known error (not initialized) caused by defective PIC (or not connected)....only check display solders....
i ordered PICs... in some days i will have and ship to you....

i would like to control if PIC is blank or damaged....please could you re-ship to me in a small letter?

bye

[Joe Gwinn]

ok.. if you have tension, your pcb seems ok and display show a well known error (not initialized) caused by defective PIC (or not connected)....only check display solders....
i ordered PICs... in some days i will have and ship to you....

i would like to control if PIC is blank or damaged....please could you re-ship to me in a small letter?

Be sure to ship the removed PIC with antistatic foam around the leads, or postal handling may destroy the evidence. Probably a good idea to put the whole thing in an antistatic bag as well.

[Jeff Callahan]

Yeah I'm sure he used all the proceedures, anti-static soldering iron and a grounding strap.

Elepro, I'll be happy to send you the PIC, PM your address.

Jeff

[Joe Gwinn]

Yeah I'm sure he used all the proceedures, anti-static soldering iron and a grounding strap.

I'm talking about the return trip to Elpro, who may want to see what happened.

[Jeff Callahan]

Sorry for the confusion Joe, I was responding to Red House. I will package the returned PIC to Elepro with as much care as possible. Thanks for all who helped me with this project, and especially Red House for putting the group buy together.

Jeff

[RedHouse]

While googling around about PIC stuff I ran across this statement about 44780 type LCD displays:

"setting up the LCD without the data pins (just power and ground) is a good way to set the contrast - as the on-board controller will fill the first row with rectangles - allowing you to set the contrast correctly"

That describes the picture you posted of your meter.


So the question is, how could the data lines not be connected since they are hard-wired on the PCB?.
(unless of course the PIC is not working)

[Jeff Callahan]

Thanks for the new PIC Elepro...

Got the PIC monday, had it put in, and still the same damn problem! Any other tests? I'm over my head on this one, any advise would be greatly appreciated.

I'll post any pictures wanted, but I've already shown what I got.

The PIC's "prongs" were bent a little during shipping, but don't think that's a problem.

Jeff

[David Schwab]

Got the PIC monday, had it put in, and still the same damn problem!

I would think it's now safe to assume the PIC is not the issue.

Maybe the display board is bad?

[-Elepro-]

I would think it's now safe to assume the PIC is not the issue.

....And to think that i have been near crucifixion for this

Maybe the display board is bad?

yes.... this is the last thing... but there is a last test:

with ohmeter check if there's Electrical Continuity in display connections....
try without pic from the socket pin to relative display pin... like in picture...

[-Elepro-]

and then check any socket pin of display with its relative pads on the top and bottom side (A with 1 .... and A with 2 .... for all pin)

..... could be an interruption between top and bottom layer of display.....

if it's all ok try another display or ship me entire unit...(but i think it's more cheap to buy another display)...

[RedHouse]

and then check any socket pin of display with its relative pads on the top and bottom side (A with 1 .... and A with 2 .... for all pin)

..... could be an interruption between top and bottom layer of display...

These LCD displays also have a second set of pins across the bottom, if you think you may have a bad connection, you can try a temporary jumper to the corresponding pin on the bottom set of connections just to test things out.
(micro alligator clip or something)

The LCD's data sheet says these important things:

(page-20 "General Precautions")
"5. When mounting a LCM, make sure that the PCB is not under any stress such as bending
or twisting. Elastomer contacts are very delicate and missing pixels could result from
slight dislocation of any of the elements.
6. Avoid pressing on the metal bezel, otherwise the elastomer connector could be deformed
and lose contact, resulting in missing pixels and also cause rainbow on the display."

(page-20 "Static Electricity Precautions")
"1. CMOS-LSI is used for the module circuit; therefore operators should be grounded whenever
he/she comes into contact with the module.
2. Do not touch any of the conductive parts such as the LSI pads; the copper leads on the PCB and
the interface terminals with any parts of the human body."

So make sure your mounting technique hasn't "clamped" the LCD display between the enclosure and it's board, and make very sure you use anti-static (wrist strap) when you are touching and handling the CMOS display at all times.

Wearing 100% cotton clothes when working on static sensitive stuff helps, and don't wear rubber soled shoes (Sneakers/Trainers) as they can develop a lot of static charge if you just walk across a carpeted floor, or rub your shoes as you sit there, specially if you're one of those guys that wiggles the foot while sitting.

[RedHouse]

Oh and BTW, I'd also like to offer to help you if you send me your complete unit.

I can test it for you, I have a "test" display (known-good) on my bench that can be plugged right in.

[Jeff Callahan]

All test come back fine...

I knew I was over my head on this one, but thought paying someone to put it together would still make it a great deal. I'm sure it is something on my end, but am not smart enough to figure it out. Thanks for all the suggestions.

Elepro, with my white flag raised shamefully, I'm shipping the entire unit to you, thanks.

Redhouse, Thanks for the offer...I'd much rather save on the shipping, but if the guy that took my money (electronics engineer) burnt another PIC, I'd be back in the same position.

Jeff

[-Elepro-]

gaussmeter has arrived yesterday.....

So the question is, how could the data lines not be connected since they are hard-wired on the PCB?.
(unless of course the PIC is not working)

....data lines are connected but there are not data....


the problem was a short (but they were 2) in your pcb .... you can see in picture.... (note that is picture posted from Jeff..... i only add rectangles

one of that pin is the clock out of MCU.... with short the clock was locked and firmware did not run....and data lines did not have data....

now i don't know what to say.....

Jeff, in a my email i said you to ship your gaussmeter without box because economic shipping from italy is max 5cm width.. now with box redhouse have to pay much more for the re-ship.......

....tomorrow i'll test with sensor....

bye

[-Elepro-]

....also, please add "solved" in trhread title.....