Replacing caps in printer

[Frick]

Hey all.

I've got this printer (Brother laser all in one something something. It's pretty good.) with a burnt cap in the PSU. There's a datasheet here. It's the second one, KH X1Y2 and it's 1000pF.

Now, the store that actually have these things (ELFA) is out of them. It used to say they would get new ones early february but now it says they'll get them March 23. Sigh.

But I just slaughterd a bunch of computer PSU's and I found a bunch of identical capacitors BUT they're 2000pF instead. It is placed just before a power connector that goes to lord knows what. It looks like this:

AC in (with filters) -> fuses -> blown cap -> power out. I've no idea where it goes and the printer is a b*tch to work with.

So, what do you think will happen if I replace it with a 2000pF cap instead? Or should I maybe take it apart completely to find out where the mysterious out leads? I mean it's totally doable but I rather not.

Thanks for looking!

[jsfitz54]

Try: www.allelectronics.com or www.MCMelectronics.com for parts.
Basic instinct would not be to double the output. 1000pF to 1200pF maybe...

[streetfighter 2]

Feel free to replace it with a cap with identical farad rating, but a higher voltage rating. On the other hand, do not replace it with a cap with a different farad rating or lower voltage rating.

There's gotta be a retailer of electronics components in Sweden . . .
http://www.digikey.se/

I think this is it:
http://search.digikey.com/scripts/Dk...me=490-4212-ND

[jsfitz54]

Airmail postage is still cheap if he can't find it there.


I think streetfighter 2 nailed it!!!!

[Frick]

I think he did, I found that one too just now.

But why can't I use a bigger one? I'm still learning all this electronic stuff.

[jsfitz54]

One word: fire.

[Frick]

Originally Posted by jsfitz54

One word: fire.

Cool. But why?

BTW I just love it when you order components for €1 and the shipping is €17.

[jsfitz54]

Shipping sucks especially when a cheap envelope would do..

Without a complete circut diagram I can't answer but you did say it was directly after the fuse and before power out, so I'm guessing redundancy.

The fuse is still intact???

[streetfighter 2]

Originally Posted by Frick

But why can't I use a bigger one? I'm still learning all this electronic stuff.

Well maybe you can, maybe you can't. There really isn't anyway to tell without looking at the circuit itself. Ceramic caps around 1000pF are pretty commonly used for improving transient response when switching loads. That isn't necessarily what it's being used for in your printer but it's possible, and in that case it might not care a great deal if you used a 2000pF capacitor (but it will put additional burden on other components).

Originally Posted by Frick

BTW I just love it when you order components for €1 and the shipping is €17.

Wow that sucks!

[Frick]

Originally Posted by jsfitz54

The fuse is still intact???

Nope.

Originally Posted by streetfighter 2

Wow that sucks!

AND that's excluding the 25% VAT. Components for €1.2 ends up costing €25 or something. Raaaggggeeee!!!!

[jsfitz54]

Forget printing...try paper and pencil

So what would be the grand total for a .20C U.S. part?

25+ Euro is about 35 dollars...

Is there an electric junkyard of some sort you can scavenge parts from?

Another thought...Sweden is big on recycling if I remember...so how about a local recycling center for parts?

[streetfighter 2]

Originally Posted by Frick

AND that's excluding the 25% VAT. Components for €1.2 ends up costing €25 or something. Raaaggggeeee!!!!

In the USA I can buy a pretty darn nice inkjet printer for €25
I hope this printer is actually worth repairing!

Originally Posted by jsfitz54

Forget printing...try paper and pencil

Seconded!

[W1zzard]

are you sure you got the right datasheet?

the capacitors in the psu should be electrolyte ones (little cans)

and the capacity should be 1000 uF not 1000 pF

[scaminatrix]

Frick, I've got one of those electronics shops in my town, you know, the enthusiast sort of guy who'll make you any length of any wire you want. Williams Radio & Electrical.
If you can't sort anything out, I'll be happy to help you in sourcing the bits you need.

[Frick]

Originally Posted by W1zzard

are you sure you got the right datasheet?

the capacitors in the psu should be electrolyte ones (little cans)

and the capacity should be 1000 uF not 1000 pF

Nope, it's a ceramic disc cap.

And it's 1000pF. The datasheet for it says:

Capactiance: Expressed by four figures. The unit is pF. The first and second figures are significant digits, and the third figure expresses the number of zeros which follow the two numbers.

And it says 102M on the cap = 1000pF with a +-20% tolerance.

Anyway, I just teared the entire printer apart and I think I found the culprit: There's a component on the fax controller board (named SW1 on the PCB and it's called Shinmei A5X-G-24E-908 | 1A 320VDC 1A 120VAC) that is completely burnt and a big chunk of the board is burnt as well. Lightning maybe? It's very common that people unplug everything but forget the fax. And there's a ground cable that goes from the PSU to the fax board so I guess that's why that cap blew and the fuse blew as well. Maybe. I'm just guessing here really.

The electronics for everything else looks fine though. The motherboard and the boards for the motor and evrything looks pristine. SO, if I can replace the cap (the fuse is already replaced) I think I should be able to just unplug the fax board and use the printer as normal. If the software allows for it that is.

And there are shops here that repair electronics, if I ask nicely maybe they can sell me something.

Originally Posted by streetfighter 2

In the USA I can buy a pretty darn nice inkjet printer for €25
I hope this printer is actually worth repairing!

It's a Brother MFC-7420 and while it's pretty old it's pretty much unnused.

And the major reason I'm doing anything at all can be summed up in one word: Learning! I grab every piece of electronics I can get my hands on just to get experience. And I think it's fun.

[jsfitz54]

Let me ask the dummy question...Have you tried to contact Brother for the FAX board? They might send you the part for little cost, that way you can have a fully functioning machine. It might be worth the trouble as the teardown is the hard part. They may also be able to help with the ceramic cap.

[Frick]

Originally Posted by jsfitz54

Let me ask the dummy question...Have you tried to contact Brother for the FAX board? They might send you the part for little cost, that way you can have a fully functioning machine. It might be worth the trouble as the teardown is the hard part. They may also be able to help with the ceramic cap.

I've thought about it, but I haven't gotten around to do it. I actually found a parts reference for the printer too. I might just contact them and see what they say at least.

[Completely Bonkers]

Getter a better fax machine on ebay for cheap.

And ask yourself whether you really need a fax machine? I understand a scanner is important, and even scan to network folder, or scan to email. But fax? There are very few examples of people that still use them other than small businesses that refuse to "invest" in up-to-date infrastructure.

If you want it for the printer feature... forget it. Older fax-machine-all-in-printer-too things have HORRIBLY EXPENSE toner and drums. You can buy a new laser printer for half the price that is faster, better, cheaper per page.

Let the old fax die...

(I have 3 pro quality xerox fax machines, all in the cellar and unused for years... just cant bring myself to bin these things that cost 2000$+ when new).

[Frick]

I don't want the fax, that's pretty much the point. If it works to just disconnect that card I'll be a happy clam.

EDIT: Why ask Brother about a new one then? Because it's possible, that's why. I just like the feeling of bringing back things from the dead.

[jsfitz54]

If you can order from USA, maybe this Co. can help: http://www.johansondielectrics.com/s...amic-caps.html

[Completely Bonkers]

Frick, I was just sharing some experience. Old printers, like old women, are not worth bringing back from the dead. I agree with "classic" cars, computers, hi-fi, architecture, antiques, sunglasses (lol), etc. but NOT printers. IF you get it going, you will spend a fortune on drums and toner and all for slow, poor print quality.

Renovation-restoration hobbies are great. But choose something worth investing your time and money in.

*edit* I just looked at your link to the model number. Oh. It's not that old. I guess it's worth giving a go if Brother has up-to-date drivers for your PC. But the reviews dont look too good! One star of 5. Perhaps you want to restore it so that you can see exactly how bad it really is! LOL

[Frick]

Originally Posted by Completely Bonkers

*edit* I just looked at your link to the model number. Oh. It's not that old. I guess it's worth giving a go if Brother has up-to-date drivers for your PC. But the reviews dont look too good! One star of 5. Perhaps you want to restore it so that you can see exactly how bad it really is! LOL

Aye, I kinda laughed at it though, the original owners never had that problem.

If I can't find a solution for it I'm seriously considering building a computer in the chassis. It would be kinda cool, if I can find parts to put there.

[scaminatrix]

I've just sent an e-mail for a quote on the cap you're looking for, should be pittence. I've shipped I/O shields to the US for less than £2. I should get a reply from them on Monday.

EDIT: Got a reply from him already!
"We would need to know/guess the voltage.
What is the circuit that it is in and/or how big is it - the higher voltage the larger the size."