Sekonic CP77 Projector problem

[wolferic]

Since buying this projector (sight unseen... an eBay delight) I have replaced the bulb and belt and oiled or greased everything I could find.

Problem is a noise related to the power supply. As soon as I plug it in, it starts a loud buzzing sound. This happens even when everything is shut off... motor and light ... and doesn't change frequency or volume when they are switched on. I can see a small blue spark where one of the brushes contacts the spinning motor. Everything else operates normally.

Before I start pulling things apart, any one have any experience with this kind of problem?

(Please note that sending ANY super 8 equipment out or repair is not an option for me, as shipping, taxes and duty would far exceed the cost of the projector. I'd really like to sort this myself if possible).

[slashmaster]

I've never heard of Sekonic. I just tried looking iooking it up on Super8data and couldn't find it. You should send them a pic of your projector and all the stats. All motors with brushes give off blue sparks when they are running so that's not a problem. The hum is probably a loose bolt or nut holding the transformer down that vibrates to the cycles. I've had this problem with other electrical appliances, tighten it up and it should be gone.

[jpolzfuss]

I've never heard of Sekonic. I just tried looking iooking it up on Super8data and couldn't find it.

That's because in 90% of all cases the Super8data is sorted by "manufacturer" and not by "brand" :
http://www.super8data.com/database/proj ... _cp_77.htm

BTW: I do have exactly the same problem as wolferic with my Bauer T610: Once it's switched on (main switch with three positions: off, 18fps and 24fps), there's kind of a "mains hum" - even though the volume is set to "off". (And the hum remains the same all time - it doesn't increase/decrease with the volume, whether film is actually projected, whether the lamp is switched on/off, ... .)

[wolferic]

Thanks for the quick responses.

Sekonic projectors also carried the name COPAL, so perhaps that's what makes them hard to find. I wasn't aware that they made projectors until just a few years ago, but a quick search here for Sekonic and you get 320 results... mostly for the light meters, but it's the same company.

The problem is most definitely electrical and not mechanical. The noise doesn't change when projector speed changes or more electricity is going through the circuit: it comes on when plugged in and stays constant.

It really does seem like something not projector specific, so I'll post a video and maybe a toaster repairman among you will recognize the problem. 8O

[jpolzfuss]

The problem is most definitely electrical and not mechanical.

It sounds like the hum only depends on the "on/off"-switch on your and my projector. So the most likeliest cause is the projector's transformer. As such a transformer produces varying magnetic fields and hence could vibrate, I'll definitely check slashmaster's hint ASAP.

[firsttimecaller]

Hi,
Trying to resuscitate this almost pristine COPAL Cp77...new belt, new bulb...no light comes through though....any ideas?
Guts all look super clean..

[slashmaster]

Hi,
Trying to resuscitate this almost pristine COPAL Cp77...new belt, new bulb...no light comes through though....any ideas?
Guts all look super clean..

Did you try using a voltmeter to make sure power gets to the bulb?

[firsttimecaller]

Finally got it running...needed a new belt and I bought a new bulb that was specced as the manual stated but it
wouldn't fire...once I replaced the original bulb...it worked great!
Super clean running!