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Thread ID: 141856	2016-03-11 18:27:00	Converting 120v printer to 240v PCB	Nomad (952)	Press F1

Post ID	Timestamp	Content	User
1417314	2016-03-15 07:36:00	Only the power supply handles the mains input. The mainboard shouldn't have anything to do with that. It will only see the output which would probably be something in the range of 12-32 volts DC. In fact you can guess by looking at the other large capacitor on the board which is the output filter capacitor. Take a look at whatever its voltage rating is and the output is going to be something a few volts less than that. Your photos show the blown capacitor well. The electrolyte liquid inside would have started heating up due to the overvoltage and this is what causes the can to bulge as the liquid basically starts boiling and turning to steam. The heat generated would have also bubbled the plastic sleeve. You're lucky the fuse blew before the capacitor vented boiling electrolyte everywhere. To know more you need to show the rest of the board, photos of the other components too. The switching transistor on the little heatsink is a likely candidate for failure, depending on its voltage rating. A look at the underside of the board at any surface mount components there would also be useful, assuming you want an opinion on them anyway. Have you not tried the new board you got yet?	Agent_24 (57)
1417315	2016-03-16 00:26:00	Have you not tried the new board you got yet? It hasn't left their country yet . Aliexpress China / Guangzhou . Probably take 2 - 3 weeks . Previous link to the power board - . dropbox . com/sh/pjox311r6csg0kf/AADkKnngyAyxXcKPP5anT9fBa?dl=0" target="_blank">www . dropbox . com I've added a few shots like underneath it, and where the fuse cartridge is . Mainboard - new added: . dropbox . com/sh/y9bzref2flfpv2r/AACqcEFj-q_HMX-dKAlGgauia?dl=0" target="_blank">www . dropbox . com Mainboard large capacitor 50V 680uF . Blurry, as I haven't took the mainboard off - saves me redoing a few 2 wire plugs . Squeezed my phone to take the shot . :)	Nomad (952)
1417316	2016-03-16 00:46:00	On the back of the power board - the scratches. That was me :blush: I tried to take the capacitor off but I didn't have desolder braid.	Nomad (952)
1417317	2016-03-16 23:29:00	Sorry, I misunderstood. When you said: "but I got a new board" - I thought you already had one and were waiting for some confirmation that it was compatible before trying it, or something. Nothing seems visibly blown on the underside of the power board, at least.	Agent_24 (57)
1417318	2016-03-17 10:35:00	Thanks. Will report back when I swap it in.	Nomad (952)
1417319	2016-03-17 22:26:00	Thanks. Will report back when I swap it in. I wish you luck Nomad, but I must reiterate my concerns re inductive spikes as over the years I have repaired something between 1500 & 2000 switch mode supplies and the modern minimalist supplies have become more fragile and much harder to repair than older technologies which had discrete components and maybe one IC. You could check everything you can think of, buy in an IC, install it, then using a variac run it up on dummy loads, and see it all go up in a puff of smoke. Hitting it with full mains will only increase significantly the risk factor. I'm not suggesting that you couldn't get lucky, but the rectifier/capacitor, inductor board may be the least of your worries. The only simple low-cost protection that might save your bacon is a device called a 'Lamp Limiter'. This puts a light bulb in series with the mains supply and as the name implies, it limits the current that can flow. You might start with a 25w [incandescent] bulb in series with the phase conductor and this will limit the initial inrush current as the capacitor charges and if the PSU puts out a voltage to the electronics, it will just glow a little. The output will not be enough to operate the printer, but neither will it destroy anything. If it glows bright, something in the printer has sucked a kumara. Look up 'lamp limiter' on Google Images, there are plenty of examples on the first page. If it passes the initial test, you then up the bulb wattage to 60 or 75 watts and try again. The bulb will not light up as brightly as the 25w, and you can start monitoring the output voltage from the power supply (not just the mains input/rectifier board). If it passes that test, you can either increase the wattage to 100 watts or take your life in your hands and go for broke, but I recommend that you take it slowly. Personally I use a variac (variable transformer) to bring the voltage up slowly on a 100W bulb, but not too many people have a stray variac under their bed, so changing lamps is the only option. You may find that you have to buy halogens to get low wattages these days, but so long as they are 230 volt and 25-45 watt the halogens should be fine. I'm not sure whether you have bought a replacement rectifier/filter/inductor board or a replacement switch-mode power supply board suitable for 230/240 volt input, but if it is just the rectifiers, capacitors and inductors it may not help you. The large heatsinks on the main board suggest to me that at least some of the key PSU components may be situated there. Good luck.......... Cheers Billy 8-{)	Billy T (70)
1417320	2016-03-20 20:46:00	I'm not sure whether you have bought a replacement rectifier/filter/inductor board or a replacement switch-mode power supply board suitable for 230/240 volt input, but if it is just the rectifiers, capacitors and inductors it may not help you. The large heatsinks on the main board suggest to me that at least some of the key PSU components may be situated there. Going by the bunch of coils and small ICs, there may well be some secondary buck or boost converters on the mainboard (likely to supply 5v or 3.3v etc for logic and other things) but they will be separate to the main supply. The motors probably run straight from the main PSU which is probably 24v or so. The PSU board he posted photos of looks all inclusive to me. I doubt it is just a line filter and rectifier. There is clearly a transformer and a switching transistor on a heatsink, and what is very likely the SMPS controller underneath in an 8-pin SMT package. Most of the feedback circuitry is done with SMDs as well. Since he's replacing the whole board, there shouldn't be a problem. (ignoring the questionability of used boards from China! - I'd want to test the 'new' board all by itself on a dim-bulb tester first, and also check the output voltage(s) before putting it near the printer, myself) I'd suspect the heatsinked devices on the mainboard are part of the motor drive circuitry, rather than the power supply.	Agent_24 (57)
1417321	2016-03-22 21:16:00	The PSU board he posted photos of looks all inclusive to me. I doubt it is just a line filter and rectifier. There is clearly a transformer and a switching transistor on a heatsink, and what is very likely the SMPS controller underneath in an 8-pin SMT package. Most of the feedback circuitry is done with SMDs as well. Since he's replacing the whole board, there shouldn't be a problem. (ignoring the questionability of used boards from China! - I'd want to test the 'new' board all by itself on a dim-bulb tester first, and also check the output voltage(s) before putting it near the printer, myself) I'd suspect the heatsinked devices on the mainboard are part of the motor drive circuitry, rather than the power supply. You may be right Agent, but I don't think a printer would require quite that much power just to transport paper. I'd prefer to err on the side of caution and trial with a lamp limiter, they are stone-age tech but are still relevant today for issues like this. Cheers Billy 8-{)	Billy T (70)
1417322	2016-04-12 05:20:00	Just reporting back. It works :D Quarter of the vivid magenta print head nozzle chart is not there but the photograph doesn't band.	Nomad (952)
1417323	2016-04-12 07:56:00	Should clear up if you run head cleaning a few times?? OR you might find one of those ribbon cables isn't plugged in properly...	Agent_24 (57)
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