Olympus BX60 Microscope PSU

[nogger]

Hi all

Anyone have or know where i can get the circuit diagram of the power supply unit for an Olympus BX60 series microscope. I have one in for repair, the main FET blew due to poor soldering in the factory. I've changed the FET & several other parts that had blown & the unit now powers up without going bang but the output is low & not regulating on load.

Thanks in advance

Graham

[paulstef]

Re: Olympus BX60 Microscope PSU

Post some pictures of the PSU please.Front and back, high res.

[Kiriakos GR]

Re: Olympus BX60 Microscope PSU

Olympus is one of the companies which always protect their diagrams from been freely availiable.
You better contact an Olympus service place by phone, and ask to talk with one of their enginners, by the hope to pass you by a quick tip.

[budm]

Re: Olympus BX60 Microscope PSU

Is this the one you have?

[nogger]

Re: Olympus BX60 Microscope PSU

Hi Budm, yes its very similiar to that, the one i have is a BX60F-3 Microscope. I saw those pics on Ebay, nice price as well so you can see why i want to get this one fixes.

I will post some pics of mine tomorrow , it's too dark here now.

Graham

[budm]

Re: Olympus BX60 Microscope PSU

Post good straight shots of both top and bottom side of the board, and also around the burnt up section.

[nogger]

Re: Olympus BX60 Microscope PSU

Ok, i will try to get some good shots. The problem started with poor soldering of the FET from new, the owner switched it on one day & bang. The track was a little blackened but cleaned up well, popped a new FET in, source resistor & followed the track back to the daughter board that you can see standing up off the main board. On there i changed the PWM chip, 2 opto isolators & around 6 small 0.25 w resistors. I cant find any other damaged components.

I'm working on the assumption that any damage will most likely be confined to this side of the opto's but everything looks fine. It's supposed to supply 12v at 100w (Halogen light ) & it has a small sub panel with a slider control so you can vary the light level. Off load i am getting around 8 volts ,sometimes 12 but pop a load on & it just falls away. Feedback issue i guess but where ?

Anyway, pics tomorrow all being well

Graham

[ben7]

Re: Olympus BX60 Microscope PSU

Maybe try checking the snubber components near the HV FET.

Does anything get unusually hot when this is running with no load?

[nogger]

Re: Olympus BX60 Microscope PSU

Hi again

Been away a few days hence the delay in uploading pics etc.
Just been checking over the boards again with the meter & thought i had found the possible fault as i found a diode D5 short circuit (missed on the original check). It has no markings except for a bright blue band & found the following link after some googling

http://www21.atwiki.jp/mcmaster/m/pa...6.html?guid=on I think its the same as the ISS119 series on that sheet

I have attached image of the diode & it looks to be the same to me. I dont have one but i do have a lot of 1n4148 high speed diodes so i have used one of them instead. It actually has improved somewhat as i get 12 volts straight away every time now but it still falls to zero on load so not quite there yet.

I'm going to remove the daughter board again & go over the boards again with the meter.

Ignore any references in the image names to 'Humax PSU' , that sjust what the camera s/ware has assigned.

Nogger

[budm]

Re: Olympus BX60 Microscope PSU

" I have one in for repair, the main FET blew due to poor soldering in the factory. I've changed the FET & several other parts that had blown & the unit now powers up without going bang but the output is low & not regulating on load." OK, so, Which MOSFET and other components in the pictures that you replaced? Designator numbers?

[g.turner]

Re: Olympus BX60 Microscope PSU

Hi, sorry to resurrect an old thread, but the PSU in my BX has just died, and this thread seems to be the only useful link around. I wonder - did you eventually manage to fix it?