Bryan Posted May 3, 2016 Author Share Posted May 3, 2016 Here's the install pics. The chip is glued on its back. Pin 1 is the unconnected reset pin. 7 wires and 2 270ohm resistors are needed to complete the installation. The good news is no traces need to be cut. The install points are: Pin 2 - Read Buttons (W067) The buttons are connected through a resistor network (actually, they're divided among 3 networks) so different voltages are produced depending on which button is pressed. This is how a single wire can read 3 buttons. Pin 3 - LED (R806) This line is connected to a 270ohm resistor that pulls the LED voltage down to where it doesn't illuminate. Pin 4 - GND (C704) Pin 5 - SDA (D292) I2C Data pin. Also connected with a 270ohm which allows data into the TB1226 to be pulled to logic hi or low. Pin 6 - COMB FILTER (IC202 - p3) The JVC's microcontroller turns off the COMB filter module by pulling this line low. The output is open-collector so we can pull it low too without a problem. Pin 7 - SCK (D291) I2C Clock pin. Pin 8 - VCC (IC701 p5) 1 Quote Link to comment Share on other sites More sharing options...
Bryan Posted May 4, 2016 Author Share Posted May 4, 2016 I'm trying to get some pictures of how much better APAC looks in NTSC with blending on. I took these two pics, but the difference is actually even greater. I can now switch between modes.I'm using bugbiter's APAC viewer. 3 Quote Link to comment Share on other sites More sharing options...
MitchSchaft Posted September 27, 2016 Share Posted September 27, 2016 Alright, I got my monitor from ebay last week for $35/shipped. I would like to do this mod. Is it the main chip on the board that you're reprogramming or the little chip that you you're gluing to the back? What chip are you using? Quote Link to comment Share on other sites More sharing options...
Bryan Posted September 27, 2016 Author Share Posted September 27, 2016 Hi, the chip I'm programming is an ATtiny45 in an 8-pin DIP package: https://www.digikey.com/product-detail/en/atmel/ATTINY45-20PU/ATTINY45-20PU-ND/735465 Quote Link to comment Share on other sites More sharing options...
MitchSchaft Posted September 27, 2016 Share Posted September 27, 2016 beautiful, thanks a lot. 1 Quote Link to comment Share on other sites More sharing options...
suspicious_milk Posted September 27, 2016 Share Posted September 27, 2016 Wow, looks nice. I've been using this model for a few years. May be looking to replace it. Makes a high pitch sound that my wife and son can hear, but not I ☺ Quote Link to comment Share on other sites More sharing options...
Bryan Posted September 27, 2016 Author Share Posted September 27, 2016 This technique could be applied to some of the other modern monitors out there that have non-defeatable comb filters. It will be especially easy if it uses a Toshiba video processor. I might try a finer mask JVC monitor in the future. Quote Link to comment Share on other sites More sharing options...
MitchSchaft Posted October 2, 2016 Share Posted October 2, 2016 Does anyone happen to know where these 2 little magnets attach? They were loose and not attached to anything. I assume they're convergence magnets. Quote Link to comment Share on other sites More sharing options...
Bryan Posted October 2, 2016 Author Share Posted October 2, 2016 Does anyone happen to know where these 2 little magnets attach? They were loose and not attached to anything. I assume they're convergence magnets. Weird, I haven't seen them in my monitors. Maybe a last-minute tweak? Can you see evidence of the adhesive (or a less-dusty spot) on the tube? Quote Link to comment Share on other sites More sharing options...
MitchSchaft Posted October 2, 2016 Share Posted October 2, 2016 nah, I looked everywhere. there's no telling how long they weren't attached, though. mine is a '97 model. and there's nothing wrong with the monitor so I guess I don't even need them. Quote Link to comment Share on other sites More sharing options...
MitchSchaft Posted October 6, 2016 Share Posted October 6, 2016 (edited) Hello, can you help me get this chip programmed? It's been a while since I've programmed chips. Which programmer are you using? I'm using the TL866 with the MiniPro software. I have the fuse bits for the chip set properly (http://www.engbedded.com/fusecalc/), but I think I'm looking for a bin file that isn't there. I'm not sure which file to upload to the code and data fields. Edited October 6, 2016 by MitchSchaft Quote Link to comment Share on other sites More sharing options...
Bryan Posted October 6, 2016 Author Share Posted October 6, 2016 The program image for the chip is the HEX file. AVRStudio also creates the ELF file which is capable of holding all the configuration info for the chip. I'm using AVR Studio and an STK500 dev. board for programming. Quote Link to comment Share on other sites More sharing options...
Brentarian Posted October 6, 2016 Share Posted October 6, 2016 (edited) Wow, looks nice. I've been using this model for a few years. May be looking to replace it. Makes a high pitch sound that my wife and son can hear, but not I ☺ I have seen this before with bad capacitors. Which reminds me I need to replace the caps on an Electrohome monitor in my PacMan cab. Flyback transformer could be a culprit also. With the low cost of this JVC monitor though I wouldn't spend much to repair. Edited October 6, 2016 by Brentarian Quote Link to comment Share on other sites More sharing options...
MitchSchaft Posted October 6, 2016 Share Posted October 6, 2016 Send it to me if you're gonna throw it away Quote Link to comment Share on other sites More sharing options...
Bryan Posted October 6, 2016 Author Share Posted October 6, 2016 All low resolution monitors will make a 15KHz whine at some volume. If the flyback or yoke coils are a little loose, it can be quite a bit louder. Quote Link to comment Share on other sites More sharing options...
MitchSchaft Posted October 6, 2016 Share Posted October 6, 2016 (edited) Ok, I got the chip programmed finally. The monitor works fine and the LED turns on when I hit the Phase button. It stays off the rest of the time. But, that's the only thing that happens. I don't get any flashing when I hold buttons down for 3 seconds. I don't notice anything happening to the screen either. I get proper voltages at each pin so I'm not sure what I messed up. I went the long way with my install. Do you think the way I did it caused problems or maybe an issue with flashing the chip? I tried 3 different chips. I selected the hex file and the elf file from your .zip when I programmed it. Edited October 6, 2016 by MitchSchaft Quote Link to comment Share on other sites More sharing options...
Bryan Posted October 7, 2016 Author Share Posted October 7, 2016 Nice install! If I had to guess, usually it's something with the fuses. I don't have my stuff handy to program a chip right now or I'd send you one. Quote Link to comment Share on other sites More sharing options...
MitchSchaft Posted October 7, 2016 Share Posted October 7, 2016 Alright, cool. I'll mess with that when I get home tomorrow. Quote Link to comment Share on other sites More sharing options...
Bryan Posted October 8, 2016 Author Share Posted October 8, 2016 Somewhere I have a spare programmed chip. I'll see if I can find it. I wish I'd written down the fuse bytes rather than the options. Mostly, we need to make sure the internal oscillator is working and that the clock is not being divided. Quote Link to comment Share on other sites More sharing options...
MitchSchaft Posted October 8, 2016 Share Posted October 8, 2016 It's ok. I think I'll try to use the fuse calculator I linked above instead of from the elf file. This will be a good learning opportunity for me anyway. I have all kinds of test equipment if you think that will help. Quote Link to comment Share on other sites More sharing options...
Bryan Posted October 8, 2016 Author Share Posted October 8, 2016 That's a good idea. I used the hex file and didn't do any checking to see that the elf was being generated correctly. Quote Link to comment Share on other sites More sharing options...
Bryan Posted October 11, 2016 Author Share Posted October 11, 2016 I found the programmed chips in case you need one. The next mod I'd like to work on is a power supply upgrade so bright areas of the screen don't cause any bending of the picture. This is a pretty common problem with CRT monitors, where the voltage sags when the guns are driven hard. 1 Quote Link to comment Share on other sites More sharing options...
MitchSchaft Posted October 13, 2016 Share Posted October 13, 2016 You got mail. I haven't had a chance to play with the fuse bits yet. Sent from my SAMSUNG-SM-G925A using Tapatalk Quote Link to comment Share on other sites More sharing options...
Bryan Posted October 13, 2016 Author Share Posted October 13, 2016 No problem. I'll be back in the US next week and I'll drop one in the mail. 1 Quote Link to comment Share on other sites More sharing options...
MitchSchaft Posted October 20, 2016 Share Posted October 20, 2016 Alright, just wanted to give a thanks to Bryan. Everything is sorted out and works as it should! 2 Quote Link to comment Share on other sites More sharing options...
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