Does anyone know of a fix for the following issue: LCR-T4 MTester v2.07 LCR Meter - Black Block Issue Turns on with quickly saying MTester v2.07, quickly displays 'contrast' and then one solid black block and no backlight. Can't test at all. Think the firmware has an issue. Anyone have any ideas on how to flash through SPI? I'm arranging a replacement through the seller on ebay, but in the meantime I thought I'd tinker with it.

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Its almost as if the 'contrast' part wants to go into a menu of some sort. I read through the original plans and it seems there is an option to add a rotary pulse encoder for menu access. Would adding this help?

2.2.5 Using of a rotary pulse encoder - p11 I'm guessing corrupt firmware, but I've got no experience with SPI or ISP serial flashing. I've flashed firmware through JTAG before though. This is the ATMEL ATMEGA328P based one. Battery is still good at 8.9v (these testers work fine down to 6.5v) The non-working backlight should be a dead giveaway that something isn't right. I've checked the SMD components and they seem ok. Any help would be vastly appreciated.

And if I'm doing something daft, please tell me. I seem to remember reading about people having an issue like that early on in the master thread Sorry I don't remember exactly where in there, but the issue I saw described was that the default contrast is set too high. Xiyonat xaqida statuslar.

Somewhere in that thread a couple of people discussed the button sequence to press to get to the menu setting for the contrast, and once that was turned down it looked fine. Another option if you are comfortable with it would be to download and compile the firmware. Before you compile it you can set what you want the default contrast to be on boot up. Although if you are building one of the newer versions of the firmware code I believe the contrast is now already set to a sensible value. If it is a case of having the contrast set to high on boot up a rotary encoder won't really help you much (actually would probably make it a little more difficult to blind navigate the menu system). Maybe try searching that thread for 'contrast' or 'boot up contrast' or something like that. Also you can find a lot of talk of how to compile/upload the firmware in that thread as well.

Ok so I've wired up the SPI pads on the tester as follows: They're actually labelled if you look under the LCD. (You'd have to remove the LCD) The LCD is model number is LX-12864B11, 128x64 resolution with backlight. And uses SPI mode to function. The one on the tester uses the 0.8mm pitch FPC connector. Programma dlya postroeniya prodoljnogo profilya avtomobiljnoj dorogi.

More info here: When tested with a multimeter, it seems the backlight only gets 0.8V. Could this be the reason why the backlight doesn't work?

Or faulty LED? How would I go ahead to program the firmware to it? I have an Ardiuno Uno R3, but its the SMD version. Ok to the other noobs just getting started: The in-system programming (ISP) programming method is functionally performed through SPI, plus some twiddling of the Reset line. As long as the SPI pins of the AVR are not connected to anything disruptive, the AVR chip can stay soldered on a PCB while reprogramming. All that is needed is a 6-pin connector and programming adapter.

This is the most common way to develop with an AVR. Here's some more info: As I'm teaching myself, I'm going to morph this thread to a guide on how to fix it. Any input or pointers are appreciated^^. Thanks to you sir, my tester is now working^^ Thank you for the guide and the pics. They really helped. Tried both firmwares, the Mtester one didn't work, just kept saying MTester and then contrast, but at least solidly for 2 seconds? The Flash K-version (v1.12kr647) did the trick.

Can I ask though, how do I change the selection menu option? Rotary encoder with a push switch and debounce chip? I think my lcd backlight led is shot, but that's easily fixed with a replacement LX-12864B11, 128x64 lcd from ebay. Do you have a bitcoin address so I can buy you a coffee/beer? Thanks to you sir, my tester is now working^^ Thank you for the guide and the pics. They really helped. Tried both firmwares, the Mtester one didn't work, just kept saying MTester and then contrast, but at least solidly for 2 seconds?