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Anyone know supply voltage for a Microtek ScanMaker 3600 flat-bed scanner? Answered

. I just rescued a Microtek ScanMaker 3600 flat-bed scanner from the curb and can't figure what kind of power it takes. Nothing on the scanner case and the web pages at Microtek just say "wall adapter" without any specs. Didn't find a SM3600 fan site, just reviews that mention adapter as being an in-the-box item. Anyone know volts, AC or DC, and polarity? . There was a slight drizzle going on when I rescued the scanner. I've got the case open and I dried what few drops I could get to with paper towels. Is there anything in a scanner that will quit working/burn up if it gets wet or can I safely power it up once it dries out for a day or two? . I don't really need a scanner, but I've read on here that the cold-cathode thingies are fun to play with. :) . TIA

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I would try emailing Microtech and asking them, they're most likely more than willing to help you.

. Looks like the server dropped my earlier post to you. Or maybe I hit the wrong button. Anyway ... . Thanks for the suggestion. I have that on my list. After looking at the Microtek site (not very helpful), I figured I'd ask here first. If nobody comes up with something in a day or two, I'll try Microtek.

Aha, found it man: Volts : 15.5 Amps: 1.25 Have fun.

. Thank you! . Where did you find that? More specifically, what search string did you use? I've only found one mention of voltage and it was a rather cryptic (to me, anyway) "15.0/15.5V 1.1/1.25A" . BTW, I've sent a note to Microtek and waiting for an answer. I'm expecting a link to buy their wall wart, but maybe they'll be able/willing to help.

It's all about knowing the right people, specifically the people that horde scanners and happened to have the same one you had. But I can garentee that Microtek will give you the same voltage.

> I can garentee that Microtek will give you the same voltage . By golly, you're right. Just got the e-mail from them. . It wasn't that I doubted you, I'm just curious as to how you found it so I can sharpen my searching skills. . . But, alas, no mention in the e-mail of AC or DC. They did give the manufacturer as "Hitron or LSE", so it looks like it's time to hit Google again. . . Thanks again for the help.

It's just DC, mostly all wall adapters for electronics provide a AC (you wall power) to DC for the device. So just go to a electronics store somewhere, maybe radio shack and pick a 15 volt wall adapter up and you should be set.

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gmoon

10 years ago

Heh, good luck.

A client of mine had some guys in to lay carpet. The client (not the tradesmen) decided to label all the computer connections. So he labeled everything (keybd, mouse, parport cable, etc.) except the two wallwarts--a scanner and a network switch.

The wallwarts were identical voltage, but different polarity. We had to guess. We guessed wrong--one fried scanner...

One more thing--you've already got the case open, so maybe you can suss the polarity from the gnd plane or any polarized caps near the power plug. Won't give you the voltage, but you might find that part elsewhere...

. Thanks. I took the PCB out early this morning and noticed a big, black diode (CR1) near the power input. Did a "block search" of the board and found CR2, but it's 2/3rds of the way across the board. . There _is_ a transformer (T1) next to the power jack (J6) - couldn't tell what it was until I got the board out - but I cannot find a rectifier bridge ("where's that confounded bridge"). CR1 looks like it would make a good power rectifier (0.203" diameter, according to my dial caliper), but there's just one. There is an 8-pin DIP next to CR1, but it is labeled "U2 U6" on the PCB, so I'm guessing it's a dual-something, not a bridge. I can't read the markings on the DIP; looks like a pencil mark over most of the numbers. . There is a thin, dark area around every every pad on the power jack and switch, such that I can't tell what is actually connected to the larger traces. :( . The xformer sits between the power jack and the USB port - could the xformer be for USB? . Been a while since I last saw/heard the word suss used.

My though was there wouldn't be a bridge if the supply was already DC, but you might see a large capacitor or two to stabilize and smooth the wallwart voltage. Might there be a voltage regulator there? (assuming the wart was 'raw.')

'course if the xformer is really connected to the power in, then maybe it isn't DC after all.. I know (older, at least) USB specs include some inductance choke on the I/O (shouldn't be connected directly to power, tho.)

Been a while since I last saw/heard the word suss used.

Been a while since I saw a zeppelin reference in a tech-type forum ;-)
"where's that confounded bridge"

> you might see a large capacitor or two to stabilize ... . There are 3 caps on that half of the board, but none that I would call large. All are rated 47uF. Two cans with blue wrappers and a slightly larger one with black. The black one has a big X stamped into the top and sits next to the big diode. One of the blue ones sits between the legs of the VRs. . > Might there be a voltage regulator there . Two, actually. A 7805 and a 7812. IIRC, that's +5 and +12, respectively. Located on opposite corner of same side of board with the jack. . Two "large" (.175x.600") resistors (Red-Blk-Blk, umm, 20ohms?), that look that they are in parallel, and two smaller (.155x.460") ones (Red-Blk-Blk and Red-Blk-Red 2K?), in the same corner of the board as the VRs . > if the xformer is really connected to the power in . If I make a few assumptions about how the board is "wired," it looks like power comes into the the jack, to the switch, then back under the jack to the xformer. I get lost after that - need a better magnifying glass. . I'm pretty sure it's a xformer - about as long as the 8-pin DIP and almost square, a little bit taller than the DIP, two coils of varnished wire, 22-26 gage (I'm not good at guessing wire size, it may be a little smaller). . > USB specs include some inductance choke on the I/O . If your talking about ferrite rings/tubes, I see none on the board. There is one on the wires going to the motor and another on the flat cable to the scanning head. There is a SMD, labeled L1, halfway between the input jack and the regulators, but it is only about 1/4 the size of the jumpers on the back of a HDD (Molex?) and nowhere near the USB port. . > Been a while since I saw a zeppelin reference in a tech-type forum ;-) . ROFL Touche! I'm just glad somebody got it.

Yeah, beats me what the transf is for... I'd check the polarity on the 47 uF cap (the diode might be wired 'backward' as spike protection, for folks that yank out the cord with the power on.) But assuming the 7805 and 7812 are TO-220 packages, I think you could trace 'em back the power plug. They probably all share the same gnd anyway...normally we all think that the incoming ground is somehow isolated from the rest (and generally it is physically close), but that's not usually the case... I really doubt it's a bipolar supply, probably just +5 and +12, so a little research will give you the gnd pin of a TO-220 version.

> polarity on the 47 uF cap . Well, the black cap next to the diode is actually 100uF, and all I can tell is the + side (side away from the band) goes to the cathode end of the diode. The anode end of the diode is closest to the jack, but I still can't follow the traces with any certainty. . > assuming the 7805 and 7812 are TO-220 packages . Yep. . > They probably all share the same gnd anyway . Eureka! Couldn't figure it out by following traces, but while I was checking the regulator grounds, it dawned on me to check continuity between a ground (TO-220 tab) and the jack. The center post is grounded. . . OK. That tells me polarity. What about voltage? Is it safe to assume that since it has a 12V regulator, that the input will be > 12V? Could L1 and one of the caps be part of a switching power supply to boost the voltage, meaning the input would be < 12V (neither L1 nor the caps look big enough to me, but if I knew that, I wouldn't be asking about the other stuff)? . . Let's assume that 15V is right. Would I do less damage if I used a DC supply and it turned out to need AC, or the other way around?

A regulator (if I remember correctly) requires at leas one volt or so above it's rating in order to function properly. Now, concerning ac or dc, it would all depend on where it is going (too much dc directly into an AC motor could cause some nasty problems. AC going through lower breakdown voltage diodes could also cause problems (if it was meant for DC or lower voltage AC). This looks like it will take a lot of sleuthing to get where you want to be :-)

Yeah, I assume either AC or DC could be damaging, if the wrong one were applied. Despite that friggin' xformer, I'm voting for a DC supply, personally. The regulator GND is directly connected to one of the power inputs, and you just wouldn't see that with AC. You'd see a larger xformer, along with the aforementioned bridge rectifier and smoothing caps. The specs for LM78xx vary with the version, I'm afraid. At one time I believe 18 volts would have required for stable operation of the 7812. Newer 7812s need less (National semi: 14.6V.)

> that friggin' xformer, I'm voting for a DC supply . I'm leaning the same way. And I feel exactly the same way about the transformer/bridge arrangement. LOL If I had an "AC" board and a "DC" board to compare it to, I _might_ be able to figure something out. . . Right now, I'm thinking about using a 15VDC supply on the assumption that if it needs AC (but where is the freaking bridge?), the transformer will block it. If it doesn't work, but I see no smoke, try 18VDC. If still not working, switch to AC at same voltages. If it still doesn't work, put it back on the curb. . I'm also thinking that we have already wasted too many resources on something that probably doesn't work anyway. . . > Heat sink? . Just the tabs on the 78xx's, but the '05 has the PCB mounting screw going through it to the metal standoff. The four resistors, the 8-pin DIP, and the diode are the only other components that look like they could handle much current. Most everything else is those teensy SMDs and ICs. . . Every SPS I've seen, has a _much_ larger inductor than L1. The one I'm looking at now has eight 100uF caps (but that's for a total of 1.7A at 5/12/-5V). But it seems they can pack a lot of H's, F's, &c; in those tiny SMDs nowadays - physical size doesn't seem to be a good indicator of _anything_ anymore.

Bridges can be very small. I have seen one not much bigger then this letter here:
=O= but it should have a + and - on it somewhere (even if you need a magnifying glass to see it....if it is there).

. OK. I'll double check. I _hate_ how small components have gotten. LOL

Tell me about it. Who in the world can read those 3 and 4 digit numbers on those "capacitors" that are as small or smaller then ants *sigh*

I have trouble with the color coding on regular resistors (bring back the wax and cardboard capacitors *LOL* ).

Also, I see what you're saying re: the 12V reg--a voltage doubler and then a regulator. Don't think you'd see that unless the 12V portion of the circuit has very low current requirements. And then I'm not sure they'd use a TO-220. Heat sink? Then I'm sure it's supplied directly from the wallwart.

. Thanks! . I checked and the motor has a controller chip (I assume that's what it is) and all the motor leads (except gnd) come from it. I might fry the controller, but the motor should be safe. heehee . The diode is a monster (.203x.357") compared to most of the other parts on the board. Looks to me like it will handle just about anything I'm likely to throw at it. Although I'm beginning to think that hooking it up to mains and doing a pyrotechnics iBles is a good idea. :)

(and generally it is physically close)

Sorry, i meant the incoming gnd is physically close to the regulator.

I think this is correct (if someone knows differently, please correct me):

Power

Power Device: Power supply - integrated

Voltage Required: AC 110/220 V ± 10% ( 50/60 Hz )

Power Consumption Operational ( Standby ): 40 Watt

. Pretty sure it takes a wall wart. The jack has a pin in the middle and a wiper on the side. I don't think those connectors are rated for 110/220. And there is no transformer inside the case. . Thanks for trying.

Never say die ;-) I hate defeat, and rarely accept it: I did blunder with my first attempt, but I DO believe I have it now: here is one being sold on eBay, so it should be a 12 v DC adaptor...
Adaptor 12vDc found here...
Sorry about that first mis-post.

. Thanks! Not exactly the same model number, but it looks like an _excellent_ lead. The one shown has what appears to be the proper connector. I'll jump back to Microtek's site and see if it looks like the 3600 and 3800 might use the same supply. If that doesn't work, I'll try searching all of eBay (I should have thought of going there before posting. Doh!). . No problem with the "mis-post." You made it clear that you weren't 100% sure. You tried and I appreciate that. If you had told me that you had the same model and that was what was on your adapter, it would be a little different. ;)

Oops, did I blunder again? (forgot the model number)....gee I am batting in the negative numbers today.....

. Still a good lead. If nothing else, you reminded me to search eBay.

I did find out one thing, this model scanner is no longer made *sigh*