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somebody
11-10-2003, 11:33 AM
A friend of mine has a Canon BJC-2100SP printer which stopped working after a power cut recently. It simply doesn't switch on at all (there is no power switch either). He suspects that it's a fuse or something which is blown. However, he cannot get into the printer because it has an odd type of screw, which he doesn't have a screwdriver for (he tried several sets of security-bit sets).

The problem is that the printer uses a built-in power supply, instead of the inline power adaptors usually found on inkjet printers, which means he has to get into the printer itself.

Has anyone got one of these printers, and has had similar problems, or does know what that type of screw is called (so he can find a screwdriver for it)? Unfortunately I don't have any pictures of the screws, so I can't post it here.

Billy T
11-10-2003, 01:03 PM
You will need to provide a description of the screw, or else he could take the printer in to the nearest Dick Smiths (or JayCar if in Auckland) as they have a big range of security screw bits.

Unfortunately it is unlikely to be a fuse failure (though not impossible) as any event in the printer that blows a fuse is likely to be a major component failure. Fuses only blow on overload and the overload has to be on the printer side of the fuse.

Another option is to take it to a specialised printer service co for a quote. With printers fairly cheap though, a replacement can be cheaper than a repair.

All the above assumes that he has checked the power point!

Cheers

Billy 8-{)

somebody
11-10-2003, 01:12 PM
He said the screw was like a circle with notches cut out of it - so it was more of a bolt head than a screw head. A bit like a * shape, except it's the shape of the screw head, not where the screwdriver slots in.

I think the reason he wanted to fix it himself was probably because it would cost about the same to buy a new printer as it is to fix his one. He has tried all the obvoius things (making sure it's plugged in, making sure it is switched on at the wall, etc.), and yet it still does not work. Is it possible that after the power cut there was a surge which could have damaged it (I don't know if he has a surge protector)?

Graham L
11-10-2003, 01:20 PM
That "sounds" like the security screws used on some of the Game units. (Sort of like a "negative Torx" head). Jaycar had a driver for that a whike ago ... they were selling a big bag of the screws with the driver bit.

Switch mode suplies are tricky to fix ... and when they blow the internal fuse there is usually a fault.

somebody
11-10-2003, 06:17 PM
Hmm... I guess if all else fails, he could always drill the screws out. Yes, the "negative torx" you mention seems to make sense, so I'll get him to try and find a screwdriver for those.

I suspect the power cut had something to do with the fault, as the printer stopped working after one recently. Is it possible that a power surge fried some circuitry in the printer itself?

Pheonix
11-10-2003, 06:33 PM
Drilling is kinda drastic. Tell him to go to the $2 shop and buy a blade screwdriver. Then file a notch in the middle, that should do it.
For you Techs, I know 9 times out of 10 , it would have gone further, but it is not unknown for an overvoltage device (damn minds gone blank on name :( )to cause the fuse to blow and not damage anything further.

Tom McB
11-10-2003, 07:42 PM
A zener diode acting as a clamp down / crow bar ? If it went beyond that or there is none then it may not be worth having repaired at a shop for reasons already previously stated.

Not sure about the total power reqs of an inkjet but isn't a switching power supply a bit over engineering it?

whiskeytangofoxtrot
11-10-2003, 07:50 PM
Go to Trash Converters, School Fair, Auction, T&E, Trademe.

Buy a second hand one for next to nothing and either swap out the PSU, or swap the ink cartridges into the second printer.

Graham L
12-10-2003, 01:13 PM
Tom: a switch mode supply isn't overengineering for 20-60W, which is what most IJ printers use. They are cost-engineered. :D

The switchmode is much cheaper to make. The biggest saving is in the transformer ... instead of hundreds of turns of windings and a laminated steel core which has to be assembled from at least 50 parts, the ferrite transformer might use 40 turns in the primary, and 3 or 4 turns in the secondary and a two piece core. Instead of a tapped primary (and a switch to change taps) for different mains voltages, "one PS fits all markets" from 90-260V, and 50-60 Hz. (A lot of transformers "cost engineered" for the US/Japan market (60Hz) overheated when they were exported to the 50Hz majority. They put in taps to change the turns, but they economised on the laminations.)

It's unlikely to have a zener crowbar for 2 reasons: the supply is regulated and should never fail :D , and a zener would add to the cost.
To blow an internal fuse, it's usually a shorted main HV capacitor,mains rectifier, or switch transistor. An overload on the low voltage side will usually just shut it down. If the output volts get too high, there's the printer to act as a power supply protector in the same way that power transisters in amplifiers protect fuses. ;-)