Pro 106 fuse replacement

johnmbb · #1 (**permalink**) 02-10-2013, 1:16 PM

I received a Pro 106 with a blown fuse inside. It is a small surface mount fuse near the battery terminals between the negative terminal and the chassis ground. I don't have the service manual to check the value. It works fine when I short it with solder, but I think it may be dangerous to run it without a fuse. I was wondering if anyone knows what the value of the fuse is so I could replace it? Maybe 1 amp or 500 milliamp?

Thanks,
John

JoeRock · #2 (**permalink**) 02-11-2013, 10:46 AM

Are you sure it's not a diode? I see two in that circuit. There are no fuses.

Got a picture?

morrisr3nd · #3 (**permalink**) 02-11-2013, 8:23 PM

According to this schematic and the list of parts, there is no fuse.

fourthhorseman · #4 (**permalink**) 02-11-2013, 8:41 PM

Quote:

Originally Posted by morrisr3nd

According
to this schematic and the list of parts,
there is no fuse.

Surveyyyyy Says!...You are correct Sir..
......(in my best richard dawson voice)

dwylie · #5 (**permalink**) 02-11-2013, 10:20 PM

Quote:

Originally Posted by morrisr3nd

According to this schematic and the list of parts, there is no fuse.

Exactly that. From what I see there was no fuse what so ever so why this there is when its not?

Never ever have I heard of any handheld to have a fuse.

johnmbb · #6 (**permalink**) 02-11-2013, 10:56 PM

Sorry for the mistake. It looked like it might be a fuse, but it was the 1 uH inductor L35. It was open circuit. Maybe someone short-circuited a power supply lead to the case and blew it. Thanks for clearing that up.

n8zcc · #7 (**permalink**) 02-12-2013, 3:42 AM

You guys were pretty rough on the OP, he was asking a question thinking the device was a fuse because of the behavior when jumped. In all reality, how many can tell the difference between a fuse, capacitor, resistor, or diode with today's SMD technologies? I know I can't and I've been in the electronics business for better than 30 years.

John - the device you are jumping is likely a diode acting as a protection device against reverse polarity of the power source.

gewecke · #8 (**permalink**) 02-12-2013, 9:33 AM

Fyi, There are SMT style fuses in small rectangle packages which are usually white in color in many consumer products and sometines crack or discolor when blown although I don't know if there any in a pro-106. I used to inspect pc boards for tommygate controllers and it was common for the protection fuse to be damaged when assemblers would use a battery powered driver to screw the board into housings and the bit would slips off the screw and damage the fuse.

73,
n9zas

morrisr3nd · #9 (**permalink**) 02-12-2013, 1:18 PM

I have the service manual for the 106. I looked in the circuit (as seen previously) and I also looked at the list of components and there are NO fuses in the circuit. The OP later said that it was an inductor L34. The Radio Shack Part Number for that is: LBC2012T1ROM. In case you are interested.

If it is the diode D39 the part number is FM4003-T or FM4004-T.

Hope this helps.