MP 7503 SC 300

[Hoosierdaddy]

I have replaced the Screen Grid and the Cor. Wire. Plus Drum and Developer recently. Is the Power Pack the next move? Or has anyone had this issue on these. Machine has 1.4 Million on it.


Thx Hoosierdaddy

[slimslob]

Re: MP 7503 SC 300

Sounds to me like that new corona wire may have broken. Happens with the martini.

[Codex]

Re: MP 7503 SC 300

I recommend in this machines to disassemble completely the charge unit and clean everything.. Before changing wire and grid. Had two mp7502 with intermittent sc300... Turned out to be a kind of oil or grease under the grid.. Maybe vaporized silicon from the cleaning web?...

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[Gab]

Re: MP 7503 SC 300

clean corona thoroughly

[skinnyb]

Re: MP 7503 SC 300

I replace assembly when I do a PM. My eyes are too old to be able to see that little bitty wire. Especially with that kind of mileage I would anyway.

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[slimslob]

Re: MP 7503 SC 300

The insulator blocks at the ends of the corona can develop hair line cracks that will collect toner haze and allow wire to arc to the shell. I also have had machines with a bad connection block on the frame that arcs to ground. If you get SC300 during copying and a solid black background band check the drum shaft continuity to ground. There is a ball bearing in the bracket that holds drum shaft that is supposed to be conductive. With age it loses its conductivity.

[luca72]

Re: MP 7503 SC 300

I have replaced the Screen Grid and the Cor. Wire. Plus Drum and Developer recently. Is the Power Pack the next move? Or has anyone had this issue on these. Machine has 1.4 Million on it.


Thx Hoosierdaddy

hi, sc300 is a classic for the corona unit based machines, generally when I rebuild that part, I replace everything, blocks, wire, covers, grille, etc, only the metal part remains.
however you can do a test: take white correcting liquid (I don't know what it's called in your area) and paint both blocks well with the brush, both inside and outside, mostly the internal one, so you can better determine if have losses ... old school!

[tjvincent]

Re: MP 7503 SC 300

Is the machine blowing toner on the charge unit ?
Maybe the dev unit is blowing toner ?

[Oze]

Re: MP 7503 SC 300

I replace assembly when I do a PM. My eyes are too old to be able to see that little bitty wire. Especially with that kind of mileage I would anyway.

Sent from my LM-V405 using Tapatalk

Same here....too many years of rewiring Canon corona AND GRIDS......now I just replace the entire charge unit.

[skinnyb]

Re: MP 7503 SC 300

Same here....too many years of rewiring Canon corona AND GRIDS......now I just replace the entire charge unit.

Absolutely. Started on Canon, restrung those wires for years starting with the NP analog then the newer image Runner digital. And the wire on a spool, not even pre measured. Those were the days. My eyes and coordination don't do that well anymore... And the assembly is dirt cheap in the grand scheme of things. I keep the wire and grid from the PM kit for an emergency. I have been known to clean up an assembly and change just the grid in an emergency but I know better than to try the wire anymore...

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[zoor]

Re: MP 7503 SC 300

I have replaced the Screen Grid and the Cor. Wire. Plus Drum and Developer recently. Is the Power Pack the next move? Or has anyone had this issue on these. Machine has 1.4 Million on it.


Thx Hoosierdaddy

Replace the front and end blocks with covers , clean the entire crown housing with glass cleaner liquid (or other that contains ammonia )

[mga]

Re: MP 7503 SC 300

I have replaced the Screen Grid and the Cor. Wire. Plus Drum and Developer recently. Is the Power Pack the next move? Or has anyone had this issue on these. Machine has 1.4 Million on it.


Thx Hoosierdaddy

Try replacing complete corona assy

[Hoosierdaddy]

Re: MP 7503 SC 300

Went ahead and replaced entire assembly. Working like a charm. Thanks everyone for the insite.

Hoosierdaddy