More Photomic iii questions- power supply/light

[Dawson]

More photomic III questions. So my power supply arrived today ($350 after shipping), first question, plugged into 120 standard power, the voltage meter on the scope won’t go over about 4 volts... is the power supply bad? Also the halogen illuminator Won’t work at all, I completely took it apart, cleaned any corrosion I found and put back together still nothing, I replaced the bulb.. whenever I plug the 12 volt lead into the ports the volt meter goes to 0. Even if I just touch the plug to any of the 12 or 6 v ports. The B and T buttons illuminate when pressed, the right sided buttons do not, the “i” button sometimes when I push it seems to randomly activate the camera mechanism.. Any ideas on my next steps on trouble shooting? Should I return the power supply ? Thank you guys! (I’m going try and post a Facebook link to video of the issues.) https://www.facebook.com/groups/Amateur ... 087223366/

[MicroBob]

Hi,
I have a Phomi 1, second generation fom the 60s and don't know the differences to the Phomi 3 in every detail. For my microscope the "ABTO" box supplies a little power for the lamp and has certain controls for the camera. While the analog camera image quality of the Phomi 3 is said to be extremely good I wouldn't use it today for the inconvenience of the film processing. So I would check what the power supply / control unit does precisely and then replace it with a compact modern power supply if possible. For the remaining 300$ you can then buy something else. I have on small lab power supply that powers my LEDs with up to 2A (?) and another one that can provide around 10A and can power LEDs as well as halogen bulbs. Both with a footprint of a video cassette or less. So this saves a lot of valuable desk space.

Bob

[Dawson]

Thanks Bob, I ended spending the 350 to get the big supply, camera works but the light doesn’t lol. I’ve checked all the connections and fuses and the bulb with a multimeter, all should be good... I’m obviously missing something I might try taking the power supply apart to see if there something going on with the 12 v outlets. That will be for next weekend when I have some free time

[Dawson]

Ps. I tried contacting the eBay seller who has not responded so it looks like I’m stuck with it. :/. Live and learn I guess

[viktor j nilsson]

Open a case against the seller - item not as described. Buyers are very well protected on eBay. If the item was listed as Used, it should work. If it doesn't, eBay will force the seller to resolve the issue, either by taking it back (seller pays return shipping) or giving you a substantial refund.

[Charles]

Yes, you can open a case in ebay for return of non-working unit and no response from seller. They usually give you full purchase amount with shipping and shipping back to seller.

[Dawson]

Thanks guys that’s probably what I am going to be forced to do. Bulbs delayed by USPS for the second time lol. Now expected feb. 1-3.

[Dawson]

Quick update and question: so I ended up taking the power supply and scope to an electrical guy to diagnose (still have had no response from eBay seller, eBay said they will refund me if I send it back to sender, but I’m not going to pay 100$ to ship it back lol). Good news is the light comes on and the power supply IS working correctly. The light only works when the rheostat is bypassed. Do you guys know what I can use as a replacement rheostat? There are so many with different values that I just don’t know what to get. Thanks in advance guys!

[Charles]

I have never replaced the rheostat and have never seen one offered for sale. A option is look for a parts PMIII to take the rheostat from.

[hans]

The light only works when the rheostat is bypassed. Do you guys know what I can use as a replacement rheostat?

Can you post a photo of it?

[deBult]

Consider a common chines LAB power supply (in the $50,= range) as alternative option (mind it has sufficient amperage power).

Have your technician bypass the rheostat and plug the trafo in a normal 120 V lamp dimmer (again: mind it has sufficient amperage power).

Note : not 100% sure but eBay may refund the transport costs (Paypal may do this as well).

[nannoconus]

Hi,

With a PM3, unless you're using the film camera, there's no real reason to use the big Zeiss box to power the scope (and thereby the lamp). Just get a used Zeiss power supply, or a generic 12V eBay lab power supply and plug the lamp in directly.

Cheers