Fluke 97 backlight inverter

[mlefe]

Hi guys, merry Christmas!
I’ve bought a Fluke 97 scopemeter and replaced the 4 aluminum caps as one of them was leaking. I thought that this would also increase the light coming from the backlight.

Instead of more brightness, now I can hear a low volume, high pitch sound from the inverter when I turn on the backlight... is this normal? Should the inverter make this noise or something else is wrong?

Thanks

[mlefe]

To be brief, for those of you that have a fluke 97: do they buzz a little when you turn on the backlight?

[willb]

Yes, my Fluke 97 does the same. I wouldn't describe it as a buzz but more of a high pitched whine. I replaced the 4 caps as well on my unit (all were leaking, back light was dead).

[joeqsmith]

There are a few threads on this site about the 97 and back light repairs.  I have a couple of them and ended up replacing the EL on both, plus one cap had failed on them.  After replacing the cap with the old EL, one was pretty loud.  With the new ELs I can hear them if I place my ear on the units.   

Link shows the ELs I used. 

https://www.eevblog.com/forum/testgear/old-philips-fluke-97/100/

[mlefe]

Excellent, thanks for the info!