Identifying something on Crate GX15R Circuitboard

[jagora]

Hello Again to all,
I wanted to ask if someone could tell me what the rectangular ceramic looking item on the crate circuit board does? It has a marking on it, and looks like it say's;
"Colber" .1 Ohm 5% CW3. It actually mounts directly behind the Reverb Potentiometer. Anyone know what it is? and could it cause my amp. to do nothing other than illuminate the Power On LED.


Thanks in Advance
Joe

[olddawg]

Hello Again to all,
I wanted to ask if someone could tell me what the rectangular ceramic looking item on the crate circuit board does? It has a marking on it, and looks like it say's;
"Colber" .1 Ohm 5% CW3. It actually mounts directly behind the Reverb Potentiometer. Anyone know what it is? and could it cause my amp. to do nothing other than illuminate the Power On LED.


Thanks in Advance
Joe

That's a .1 ohm ceramic resistor. It should measure nearly a short with an ohm meter. If it measures open it's bad. You can measure it in circuit.

[Enzo]

If the problem is no sound, it is way more likely the problem lies in the external speaker jack or the headphones jack, either of which have cutout contacts for the speaker.

[jagora]

Enzo,
I've already replaced the input jack and the headphone jack and it still doesn't work

Joe

[jagora]

Enzo,
How often do those ceramic resistor's go bad? And what causes one to become inoperative?

Joe

[jagora]

OldDawg,
Where do you measure the resistor? You say it should measure nearly a short. What do you mean by this? I thought if a component did not register on an ohm meter it would be considered Open/Bad?

Joe

[g1]

Open is the opposite of a short. A very low reading like one or zero ohms would be a short. Like when you touch the 2 probes together. An open will read high like when the probes are not touching anything or "OL".
There should be a metal lead at each end of the resistor. Measure the resistor by touching one probe to each end.

[Enzo]

You measure a resistor end to end - one probe on each end. Your reading will either be good or bad. Good is low resistance, like touching your probes together. Bad is one or a bunch of resistance.

You replaced the phones and input jacks, but note I mentioned the external speaker jack.

[Enzo]

Oh, and it doesn't matter how often resistors fail, all that matters is whether YOUR resistor failed or not.

[jagora]

Enzo,
The Crate Amp doesn't have an external Speaker Jack. And thanks for clarifying resistor measurement and testing.

Joe

[jagora]

g1,
O.K. and bye the way thanks for your time to explain.

Joe

[Enzo]

Sorry, my GX15R schematic and layout has one.

[jagora]

Are We are talking about the same model GX-15R Serial # GX1DF50852?

Joe

[Enzo]

Crate GX15R Yours may be a different revision level than my drawing, but you didn't post a schematic, so this is as close as I could get.

Resistors check the same way regardless.

[g1]

The Crate Amp doesn't have an external Speaker Jack.

There isn't a jack called 'speaker' next to the headphone jack? All the GX-15R I can find pictures of have it.