| Electronics > Repair |
| CIRCUIT INTEGRE 1A374 SK202 G16BAN |
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| timeandfrequency:
Bonjour Hila ANGALIKIANA, As fzabkar pinpointed, Sanken seems to build several PWM controllers in DIP packages having an odd number of pins :) The STR-A6000 Series also features a DIP7 package. The 'SK202' marking also shows up on the STR-A6059 part (see attached picture), and I either couldn't find anything about that '1A374' marking. This IC seems to be an unobtainum. As the SMPS is plainly dead and there's not much else to loose, I would suggest to hack it by implanting another PWM controller, from Sanken or maybe a Viper ? Can you please upload a hi-res image of the solder side of the board, so that we can try to figure out why this IC has 9 pins... Tu lis l'anglais, ou je t'ajoute la traduc dans ce message ? |
| Hila ANGALIKIANA:
Thanks for your intervention, I agree to hack the system, I am even up for a proposal to implement another card that I can use for the printer. I send you some pictures of the card as you asked me. |
| coromonadalix:
--- Quote from: timeandfrequency on October 22, 2024, 04:29:52 pm ---Bonjour Hila ANGALIKIANA, As fzabkar pinpointed, Sanken seems to build several PWM controllers in DIP packages having an odd number of pins :) The STR-A6000 Series also features a DIP7 package. The 'SK202' marking also shows up on the STR-A6059 part (see attached picture), and I either couldn't find anything about that '1A374' marking. This IC seems to be an unobtainum. As the SMPS is plainly dead and there's not much else to loose, I would suggest to hack it by implanting another PWM controller, from Sanken or maybe a Viper ? Can you please upload a hi-res image of the solder side of the board, so that we can try to figure out why this IC has 9 pins... Tu lis l'anglais, ou je t'ajoute la traduc dans ce message ? --- End quote --- but the number of pins does not fit, le nombre de pins nest pas bon |
| timeandfrequency:
Hello Hila ANGALIKIANA, Yes I know : none of the IC's I mentionned has 9 pins. So it will require some sorcerer tricks to use one of those as a replacement for the dead PWM controller. Luckily, the PS housing gives some clues about the printer's power requirment : 24 VDC 0.3 A 32 VDC 0.45 A 1) The easy way This Canon power supply matches the requirements. Might be a different form factor but OK, it should work. https://www.ebay.co.uk/itm/253961143068 2) A bit steeper 24 VDC power supply : https://www.reichelt.de/de/en/switching-power-supply-15-w-0-62-a-24-v-snt-rs-15-24-p137083.html For 32 VDC, start with this one : https://www.reichelt.de/de/en/switching-power-supplies-36-w-36-v-1-a-mw-lrs-35-36-p202957.html followed by a LM317 regulator + heatsink For 32 VDC output R1 = 470 Ohms R2 = 11562 Ohms (10k fixed resistor + 2k2 adjustable resistor) https://www.omnicalculator.com/other/lm317 Use a vanilla multimeter to adjust the output voltage to 32 VDC. 3) The hard way A closer look to the solder side of the PCB gives some information about that weird PWM IC (see attached picture) The +320 VDC and 0V rails are easy to find. For the PWM controller : Pin 3 GND Pins 8, 9, 10 High voltage switch drain connexion Pin 1 must be the source connexion of the high voltage switch, because R104 (probably a very low value) seems to act as a current shunt towards the 0V Pin 6 is some kind of startup power supply because it's rectified from the mains with 2 x 3k3 in series Pin 4 is probably the feedback signal coming from the optocoupler (it's not easy to follow the tracks under the SMD parts). There are also very small (0402 ?) SMD parts going from that track towards 0V. Pin 2 is the IC's power supply, coming from the AUXilary primary winding through 2 x 5,1 Ohms, and an SMD diode. There's also an unknown SOT-23 SMD part in the path (I marked it TR?). Of course, selecting a 'compatible' PWM IC is far from easy and the magic smoke might show up. One additionnal difficulty is that we don't know the switching frequency of the original part. The ferrite transformer has of course been manufactured with a precise primary inductance, that matches with the PWM IC switching frequency. And of course, all of the electrolytic capacitors must also be replaced with new ones. Update #1 & #2 & #3 : typos |
| Hila ANGALIKIANA:
Hello engineer, the first option is the simplest as you said, I looked at the other two options which are more complicated for my level, I take the first option, I just want to say that you are geniuses, and I am very happy and proud of each of you for the time you have dedicated to me, your reflection and analysis have helped me a lot, you are truly geniuses, thank you very much, God bless you |
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