Beseler Dichro 45 Repair

My unit fails to do anything when I plug both plugs in except to spin the fan(no led displays or main light). The leds should turn on even if the bulb is bad I believe.

I labeled and removed the circuit boards as post #7 describes in this thread: http://www.largeformatphotography.in...ad.php?t=11174

While I was cleaning the processor board I noticed one of the ICs had two of the pins bent out not inserted into the socket. here's a a couple pictures of what I'm talking about: http://i371.photobucket.com/albums/o...8/DSC_0176.jpg http://i371.photobucket.com/albums/o...8/DSC_0177.jpg

I'm guessing this might be my problem since the other connectors look very clean. I just thought I should try to get confirmation that's not how it should be.



I also need to fix the yellow filter cam mechanism as it won't move through its full range. It moves from the "in the light path" position for the about one turn of the knob or up 3/8" vertically then cam begins slipping on its axle. Any suggestions with this?

I decided that fixing the IC pins really was a no brainer and it turned out to be the problem! It works now except for the yellow filter cam slipping! Awesome :D

Nice fix. Sometimes these things are pretty easy to fix once you take the lid off.

White you're at it, that purple axial lead capacitor (c16) looks like it has a cold solder joint on the left connection. The solder should cleanly flow onto the capacitor lead. You'd have to flip it over to verify.

Could just be the lighting though. reheating the connection with a soldering iron should fix it, if that's the case.

I took it apart even more to get at the gear that was slipping on the cam axle and fixed it with some epoxy.

The last issue I've noticed is the magenta filtration is going between a range of 1.0 and ~2x.x when it should be whole numbers with no decimal point. The cyan and yellow act normal. That's pretty weird that its using a decimal point on one color. I looked in the manual and it says all the channels should be whole numbers. Maybe that chip is damaged from being insert wrong or it just needs to be calibrated. I don't think it will really affect that enlarger in use but its just a odd little quirk.

Bummer, the head went strong for a long 12 hour plus darkroom session but it stopped working again! The leds and fan work but no main light. Maybe my bulb went out. It has no continuity or resistance on my meter but I don't think that means it's dead per se.

The bulb should have resistance when good and should show open when bad. If it blows another bulb you have a stablization issue. (Or a batch of bad bulbs- or the wrong ones)

Quote:

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Originally Posted by natek83

Bummer, the head went strong for a long 12 hour plus darkroom session but it stopped working again! The leds and fan work but no main light. Maybe my bulb went out. It has no continuity or resistance on my meter but I don't think that means it's dead per se.

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Does anyone have a schematic for the Beseler dichro 45 color head and control box?