CTM644 died quickly

[Bignumbas]

My working 644 suddenly died and after much voltage testing I find I have 130 volts up to an IC labeled ICP501 with two legs and no volts on the other leg of it. It looks like a two legged transistor with N20 and F written on it.  It is only found in the amended service manual schematic. It describes the IC as being an ICP-N20 It was not used in the original 644.
On looking up this chip it appears to be a Fast Fuse rated at 50v 0.8a like this http://www.logingel.com/1233/174389/0/ShowProduct/Fuse
Please correct me if I am wrong.
Another question is what would make this blow?
I can only get some glass fuses rated the same and will try one or maybe just wire across it and see what blows, then I will know what parts have failed

[tjohnson]

Try changing the fuse as you suggest, these monitors are old beasts now, if it blows again then you know you need to start looking for other issues.