EBME Forums Forums Maintenance Technical Assistance isolette infant incubator model c86 h

Good day!
Im looking the value of capacitor C4.this unit is very old causing the capacitor farad to be erase. its only indicate in board as C4..

Thank you.

Kabayan,

This model is a bit old and if you google about it there was an issue of overheating because of sensor problems.
I still have an old C100 service manual and that was late 1989-90 model.
I know the situation that we Biomeds in our country are expected to repair equipment no matter how old or outdated. But in the interest of PATIENT SAFETY(and protection of the Biomed from legal issues later) I suggest an upgrade to a newer model.

bong

But what's the value of C4 ...?

I don't have a manual for this old incubator, but later models (C-100 et al) quote various values in this position.

However, I did notice that surrounding caps seem to have similar (or the same) values.

So my suggestion would be to have a look around those nearby components.

Failing that, take a look at the circuit (and what C4 is supposed to do), and make a best guess at its value. In other words:- an engineer's approach!

But lastly, are we sure that C4 is faulty?

C4 is filter cap. connected to 12.8 ac common pin of center tap transformer...

Iwill try 470uf/50 lets find out what happen.

capacitor get bulge after running 1hour,therefore its not 470uf/50.. maybe higher.

...try another one.:-)

Hello Ariel

Is this a filter capacitor (to take out the possibility of high frequency spikes etc) which is likely to be a low value cap. or a smoothing capacitor (usually after some kind of rectification).

What does the voltage look like on an oscilloscope?

Lee

"Bulging" could also be due to a poor quality cap! See here.

Bulging capacitors usually have an high ESR (and you always want a low ESR) - in other words, it indicates a faulty cap (obviously).

You could try one rated at 100 Volts working.

There is a lot of good stuff about caps on the web. For instance:-

1) BadCaps
2) ePanorama

...after simple computation of filter capacitor..

47uf/400v is suitable to replace the unknown bad e cap.

my incubator running 1 week now..temp is closely monitored.

Good work.

Thank you boss Geoff

..When we repaired dead machine and returned to its full original function to the very less expensed. The pride of being a technician.. The feeling is its better than sex.

this is what we are.. :-)