Power Jack PSWGT-1200 manual/repair guide

Great stuff, thanks for your reply, I will take on yor advice, and hope to hear from SID soon. I have seen that these LCD boards power up from 12v, so before I dive in, I had a magnified inspection of this board. This is a Power Meter-DC REV:1.3, 2014-12-10. I have seen later boards that have a harness soldered to the board, however mine has 3 plug sockets, L1, L2, L3, L3 being 12v. I have noticed on this board that it has a SMD capacitor missing at location C2, which is next to the LCD microcontroller, PIC16F1939, would anyone happen to know what the value of this is, because I have a feeling that this is what is stopping the board from working.

Thanks a million guys,
Cheers.

This I cannot help on; I do not know anywhere to purchase said sensors except from Power Jack themselves.  No idea what the specification is on the grid-tie boards.  Remember, PJ is extremely good at actually soldering in different resistors/caps to make something work--making it impossible to provide a blanket across-the-board answer.

Have to dig through my boxes to see if I have a junked LCD board of that version that happens to have that cap on it, desolder the cap and measure it with my meter....

I haven't responded to any of these things because I don't have the answers.  Have never seen one of the grid-tie inverters in the first place, never looked inside or done any digging into them.

Looked at a board.  Don't think I'll be able to measure that cap with my meter (resolution ~0.1nF), though it likely is somewhere in the 10-47pF range.  I'd guess 22pF, as it's a crystal load cap.  Likely should run fine without it, though...just not as stable or as accurate.

Best I can measure is that it's ~22pF (that being a common size somewhere close to what my meter measured).

The LCD board under test worked just fine without C2.

Hi SId,

Great stuff thanks for researching for me, really appreciate it. Looks like this board has had it as I have tried to power it up off a 12v supply with no success. Shame.

If you have any other ideas I would be highly appreciative.

Many thanks,
Col.

Guys,

Think I am going to give up on these PSWGT-1200s, just blown 2 IGBT during a power outage on my one without a display, these are useless, and only fit for a door stop in my opinion. Been working fine for a few months, but whatever savings I make they go right back into parts replacement. My PSWGT-1200 with the lcd is still proving a head ache. The LCD board does power up to an extent, there is no back light and I can see the matrix is on, however it might be the smd transistors that switch on the pic micro controller and the led back light as otherwise I have another door stop. Dah.

That's what I decided a few years ago.  Put them on the shelf in the back shed and forgot them until your posts. 

Mine worked somewhat haphazardly when I was trying them, but even on their best days never seemed to produce the power they should have.  And then they would go up and down in output under steady sun for no obvious reason.  Soon tired of them and went to some Xantrex grid tie units.  Those worked pretty well until the day the power company showed up.  (Big Brother doesn't care much for renegade solar producers)  Threatened me with all kinds of problems, so shut them down and only do off grid solar now.

The backlight is controlled by a transistor--but the MCU should be wired directly to the 7805 (5-volt linear voltage regulator).  It's not improbable that the PIC got toasted--though I haven't personally seen that on the PJ LCD boards.

If the 7805 isn't functioning correctly (i.e. ~5.0v on the output side of it), that'll definitely cause issues.  Anything past 7.0v on the output of the 7805 will destroy the LCD and the PIC.

I worked from the 7805, and that is producing a steady 5v. I think I have spotted it, next to the PIC, there is a location for Y1(oscillator) I think, is there supposed to be a component at this location as it is missing. Maybe thats the cause, I missed this as I thought it was located on the underside of the board.
Any help here is always deeply appreciated as always.

Many thanks,
Col.

Lots of microcontrollers do have internal oscillators that will run without an external crystal / resonator just not as stably.  What's the part number on the PIC?

PIC16F1939 is one of them by the looks of it.

Thanks, this board though appears to have had an oscillator fitted as I desoldered the legs of it, so depending on if the pic has been programmed to fall back to the internal oscillator, i think I need this as it was on the board, just need to know the frequency value.

Thanks for your help, cheers.

Crystal is 8MHz. 

Yes, the PIC has the ability to use an internal oscillator, however the configuration bits are set to external oscillator only.  So without a crystal, it won't run.

Thats fantastic news, wow, you are a genius, I looked at the PIC datasheet, and kind of got my head around it, and could see some of the registers that could be set, sorry I didnt mention this fact before that there was something supposed to be in this component location. Alrighty, Im going to get a new crystal and go from there.

Thanks a million, great info, will let you know how I get on.

Kind regards
Colin.

If you just want to test it, you can pull a colorburst crystal off an old TV (3.579545MHz)--or a 4.0MHz crystal resonator off a junked board...and throw it in there just for test purposes.

As the power sense IC (CS5463) has its own 8MHz crystal, the board might work fine, if slower on the LCD.

EDIT: nothing's RS-232 on the board, it's all clock-gated--so the PIC oscillator speed isn't critical.  According to the datasheet, any crystal between 4-20MHz will probably work fine, as the config bits would have it set to HS oscillator.

If its possible, could anyone post a pic of the ct clamp at all please, with the model number of it so I can try and source a compatible one I can fit to my monitoring board. Would be greatly appreciated, as I dont have another unit to swap one out of.

Many thanks.