Main > Monitor/Video Forum
HDMI to Old CRT
abstract3000:
Alright then, So i get a bunch of resistors in on Tuesday, I will get the 1K resistor put back into place where the 75 Ohm one was, and solder in a wire skipping the Diode. This will also give me a couple days to try and trace the wire from the pot back to the board and see If I Can identify what exactly is happening there, and I will use the multimeter to try and get a voltage reading off of the pot.
abstract3000:
well not the best of news, and feeling like an idiot at the moment. So I tested the 1k Resistor it did absolutely nothing, I was concerned I was not seeing anything so i used the multimeter to check the resistor and even tried a 2nd one and no dice. I then tested the 75k and it went back to how it was working previously...
So I leave the garage, and come back several hours later, Monitor is black I assumed I turned it off. What i didn't realize was that the PC shut down cutting the 12v to the Ultimarc adapter causing the screen to go black, and I went to desolder the diode and try without it....yeah so things got ugly, I see a flash on the screen and here the TV power off. At this moment I here a slight clicking sound when plugged in but no screen. My guess is with the mod on the diode I shorted out where ever it came from the board either destroying a capacitor or messing something else up in the power supply this is beyond my capabilities I'm afraid. Thank god I got the Panasonic...
Zebidee:
RIP Sharp. Sorry for your loss. Seems like the RGB-OSD mod was causing too much pain anyway, and might never have worked well.
That clicking is likely the protection circuit cutting off power. Something is out-of-whack in the power circuit. This is probably good news as easier to repair than a shorted jungle IC. You might be able to find a failed part by backtracking the 5v supply line. If lucky maybe just a fusable resistor or power diode, easy to check these with a DMM. Sometimes the damaged part/s is obvious, sometimes not. Sometimes you can smell the "magic smoke". Maybe your mate can help.
abstract3000:
You know my friend could certainly Troubleshoot and identify and even resolve the issue with parts being available, but at this point he appears to want nothing more to do with the project. I completely understand as he has dispensed enough time and effort to get me this far, wanting to move on to other paying jobs and leave this one behind, and that is completely understandable. To be honest I'm surprised you have stuck this out as long as you did Zebidee, and for that I am extremely grateful.
Many posts ago, I stated I needed to really consider the costs and initiative to this project, and where to draw a line. So far its just putting more money and effort on trying to find that "fix", I feel like such a complete idiot and should have physically checked the TV was unplugged, but its just another reminder to move on, with several red flags along the way.
I can't help but feel deflated and a bit of a hit to my ego, as I truly am fascinated with Electronics, never thought i knew to terribly much, but never thought i would make this blunderus of a move out of carelessness. Though wakabavideo's adapter is in Los Angeles Right now on it's way and I have a direct swap over. So as hard as it is to just let it go, I feel it's time to put this to bed, use the other Monitor with the plug and play option (verified on a cheap Chinese adapter) and stop dumping money into it.
If the CRT will fit into the Panasonic Housing by chance (I have little faith that it will (but if so) I will hold onto it a bit longer as it will be easier to store and maybe down the road i can have another look. Though if not I just can't have that CRT in the massive temporary wooden frame sitting around exposed, it's hard to move and not well protected, and letting it take all that space up for an inevitable event the neck gets broken by accident seems wasteful, but I will see how it goes this weakened.
Zebidee:
Argh. Nevermind. To screwup is human. Ego takes a beating, but it will recover. Learn from mistakes. Time to move on. At least you didn't fry.
Offer the Sharp for free online, here and elsewhere.
If you measure the CRT's yoke impedance, you can attract interest from people wanting to do a tube swap.
Just set DMM to ohms (set to low ohms if not autoranging) and get the readings across both horizontal and vertical yoke coils. You can access the large pins near neck. Alternatively, you can unplug the 4-pin chassis connector and put your probe leads into the female pins. This ensures a good connection.
Good idea to zero the meter's probes first (hold probe leads together for a few seconds, let readings approach zero/settle), as the horz coil readings in particular can be quite low in some yokes, and a few ohms difference can be important.
When done, stick down some paper/masking tape somewhere convenient, and write down the H & V coil readings on it.
You'll also need to count the number of pins around back of neck (you may need to remove the neckboard to see clearly).