Thank you for your answer. Now can you use a 62.5 micron fiber patchcord from the 50 micron wall jack to a Cat5e media converter?

Are you going to connect Gigabit card in your switch to the Media Converter by a 62.5Micron Patchchord and in between fiber is 50Micron?

If i have understood corectlyand your setup is like this

switch -62.5micron Patchchord -50Micron Fiber- Media Converter

Or

Switch- Media Converter -62.5 Micron Patchchord-50Micron Fiber

I dont see see any problem in any of the above setup if distance is well within the limits.

ONLY problem i could see is that you will get a shorter distance when you are mixing 62.5Micron and 50Micron than when you have all 50Micron.

It will be connected like this. Switch-50 Micron patchcord-50 Micron fiber infrastructure-62.5 Micron patchcord-Media converter-Cat5e to desktop. Should not exceed 200 meters.

Few meters of 62.5 Micron Patchchord will not be a problem i think if distance is within 200meters.

Your setup should work.

R u using WS-G5484 card in your switch?

Yes, but only to connect the switch to a Cisco 3825 router and to connect to another fiber switch. The fiber ports that I'm asking about, are the 24 ports on the switch. Not the GBICs. The 24 ports are permanent MTRJ ports. Can't be switched out.

Although it is technically feasible to combine 50 micron and 62.5 micron core multimode fibers in the same system, there is a one-time attenuation loss when coupling 62.5 micron fiber into 50 micron fiber.

Given the reach of a 100Base-FX link (2km), there is a good chance the system can overcome the additional loss at the 50 micron/62.5 micron interconnection. You can always replace the 62.5 micron jumpers in the event the system is not functioning properly.

GLC-GE-100FX SFP-GE-F

these are the type of 24 FX ports used on 3550 and on 62.5 & 50microm can go till 1.2miles (2Km).

Power is lost when you connect fiber of Different diameter like in your case from 62.5 to 50 since your distance is within 200m so should not be a problem.

Thank you for your answers. It was very helpful.

After your transition, let us know how it worked out!