Unfortunately, I do not have an oscilloscope yet, but my Fluke usually is great at picking small frequencies. I get ID at 1.6V with no fluctuations
Checked RIDs also connected 2 different combinations for JBC and Hakko T12. Iron ID is stuck at 0000 regardless if I put a calibration resistor or RIDs
Combining both fails, it looks like you have a very bad interconnecting cable ( measure the resistance on all connections) and an extra bad current source (667mv- maybe it is much more, but it is cut from D20). I should see it earlier. As I said I was tired,
I there something I can check related to this? With Hakko RIDs I get SENSA - 2.43V SENSB - 2.43V
Also is it normal to get C20 at 15V instead of 12V as specified on the schematic? Would this be reflecting anything?
Thank @minkok again. I understand that you are busy and highly appreciate your time to debug it with me. I have been over a year on this project, so whatever time it takes.
I have removed all J9 cables between the back and front and soldered direct cables instead Also checked the conductivity on J8 to make sure those lines are ok too.
Soldered the calib resistor directly on the back board and calibrated both heater outputs. This is what I get now
I think the reason why my temps were off was that I am using NT115 iron. After spending some time with JBC representative over the phone. I gathered that it's not cross-compatible with other JBC units and handles. He mentioned that it requires less power, I assume he referred to lower voltage of driving the C115 cartridge too, That might explain why my temperatures were off.
I redid measurements - on the right with a 10Ohm calibration resistor between Vout1- and SenseA U14:2 2.1V | 1.97V U12A:3 2.7V | 2.59V current through calibration resistor ~380uA, so, voltage drop on it 3.8mV | 0.0038v - 3.8mV U16A:2 3.8mV | 6.8mV U18B:5 3.8mV | 6.8mV U18A:3 0V | 2.6mV U13A:1 106mV | 107mV U17:3 53mV | 1.55V U17:6 1.5V | 1.55V
I cannot get it to detect any soldering handles. I thought if I just placed Rid-1K and Rid2-5.6K for T12 (I have a Quicko T12-952 cheap Chinese iron I can experiment with) with no iron connected, I should get T12 detected on the screen. But instead, says: no instrument. I have removed all cables and directly soldered resistors to the back board.
When I measured at Vouts with T12 RIDs I got this Vout1- 0.02V - is this normal? Vout2- 1.59V Vout1+ 6V Vout2+ 6V
Bizarrely I get 15V instead of 12V Vin. How do we expect Vin to be 12V with a 15V zener?
Some measurements which looks bit odd? U2/1 - 0.16 U2/2 - 0.03 U2/3 - 0 U2/4 - 0.03 U2/5 - 0.13 U2/6 - 14.6 U2/7 - 14,5 U2/8 - 0.15
Hello IT-Solve, sorry for the delay, but I am very buzzy on working days, and sometimes on weekends also.
Change the current to 128 and try again to make calibration to reach the right value for R in the menu. in case of a problem, make a screen copy for us.
Thanks @minkok, now I cant even detect the soldering iron. It just stays at NO INSTRUMENT. Before at least it would heat it with 100*C off
I went and moved each component one by one to a new front board by checking each IC individually. I have changed the current. Something strange is happening now. I have this exact encoder switch, and when I rotate the knob, it jumps forward and backward. Not sure if anybody had that one before. It's connected this way
I have a 100ohm calibration resistor between VOUT1- and SenseA These are the measurements I get
Reset current to 128 and do some measurements: U14:2 2.1V U12A:3 2.7V current through calibration resistor ~380uA, so, voltage drop on it 3.8mV U16A:2 3.8mV U18B:5 3.8mV U18A:3 0V U13A:1 106mV U17:3 53mV U17:6 1.5V Readings may have some flickering due to tool detection algorithm.
My measurements are on the right with calibration resistor U14:2 2.1V | 1.97V U12A:3 2.7V | 2.59V current through calibration resistor ~380uA, so, voltage drop on it 3.8mV | 0.08mV U16A:2 3.8mV | 667mV U18B:5 3.8mV | 0.66V U18A:3 0V | 0V U13A:1 106mV | 3.18V U17:3 53mV | 1.54V U17:6 1.5V | 3.15V
OK I am back after a year ignoring this 5.2C project, which was collecting dust. I have finally managed to get my hands on ADG734 and order couple chips as last we spoke @minkok we were suspecting ADG issues. I replaced U16, U13, U18 and still seem to have a similar issue where the iron is around 100-200* off the scale. When I set 100* iron stays at 100*, when I set 200, iron stays at 120*, at 300* iron is under 160*
Another thing I have noticed is that when I change the calibration value setting in menu and I exit and reenter it forgets its setting. Would that be a faulty MCU or FW I have loaded?
Calibration doesnt go below this
Can someone swing me in right direction to check.? I have touched up every component on the board. Feels like I m so close, but yet so far
I am frustrated with this project as I have spent so much money and time on it. I don't know what else to do.
No Short between IN+ and GND of U16 I have already replaced U16 once, very hard to get this chip. Can I move Calib Resistor to SENSEB - VOUT2- and see if IN- will get 3.8mV ? To confirm if the other side of U16 is functioning before I order another one and wait another 2 months.
Removed U18 to check if IN+ will be different without it, but still -0.48mV
What do you get at IN+ (-0.8mV) and IN- (-0.8mV) ? All other pins apart from 4/8 on both U13/U18 are -0.8mV With RCal connected I get almost no voltage on Sense onwards. I would have thought I should get couple volts at least on SENSEA/B
SENSEA - 0V SENSEB - 630mV
Also when I put my probe on C23 GND LCD goes all jittery
1. I connect the Calibration 10Ohm Resistor between SENSA and VOUT- 2. I turn on the power and I go to the calibration screen - I get this 3. Then I rotate the knob all the way down until I reach 1043, whish is lowest it goes
1, You need to measure current from the current sources A and B - from sparkybg "Go to calibration mode (without instrument attached) and measure the current between SENSEA and VOut1-. It is microamps, so set your multimeter accordingly. When CURRENT: 0 128 is shown on the displey, the current must be around (1.225(current source voltage reference = 1.225V)/1600(current sources shunt resistance = 1500+100=1600 ohm)/256(current source digital pot steps)*128(what the display is showing) = 382.8125uA" 2. The problem is you have on the display shown 256 instead of 128 and I don't know where it comes from - hardware or software?
I measure 0.380mA when in Calib mode without the Rcalib. Should it be in uA ?
Open Source Hardware
I don't know what else to do.
