Fender Stage 160 need help

[Jam]

I have a Fender Stage 160 amp and it was making a odd noise. So I opened it up and C63 was needed to be resoldered . So put it back and I played it and it was fine at first but then the distortion was getting thin like a cheap metal pedal. I opened it back up and was looking and I saw that D47 diode had like white powder under it. I think that is my issue but I dont know what caused it ? Does it fix the issue ?

[Gunny]

If the usual volume of the amp returned after fixing the solder joint at C63, that should be the end of that symptom.
As for D47, measure the voltage at TP34. The drawing notes at location B8 give 4 voltage readings which are dependant on footswitch and panel switch settings. If the voltage at TP34 is way off, that zener may be the problem.

[Jam]

Fender stage 160??

I replaced D47 but I get about 9.2 V at TP34 that is a lot higher

[Gunny]

but did you test and record the voltages at TP34 with the footswitch selected to Drive and to More Drive. And did you measure and record the TP34 voltage with the panel switch selected to Drive and More Drive?

Need to know the results of those measurements.

does the amp change 'channels' with the footswitch and panel switch? - all combinations working?

[Jam]

Fender stage 160

I checked it at TP 34 and with the button in it was around 9.2V and then out it was around 5V. What would cause D47 to go bad ?

[Gunny]

that diode is a 10 volt zener regulator. the voltage across it should not exceed 10 volts (within its tolerance), but may be lower (depends on switch or footswitch settings).
Diodes can fail for a variety of reasons - sometimes it's just not a logical explanation.
Still wondering if the amp changes channels OK or not. Unless we know that we can't say that the diode is bad.

[Jam]

Fender stage 160

I already replaced D47 but with no channels it is 4-5Vs and with the ch select it is 5V and with just the more drive it is 9.2V and with both it is 9.2 v

[Gunny]

still waiting for an answer to the question....does the amp actually change channels the way it is supposed to? If it changes from green to yellow to red, TP34 voltages aren't critical.

[fsdrumerkid]

How-to

how do you know the numbers of all these solders and various points do you have a schematic with them labeled like that? sorry im an electronics noob please help

[Gunny]

If you are an original Fender amp owner, you usually find a full schematic and layout drawing inside the back of a combo amp. In addition, those drawings are available from the Fender website. Most of them are available for free. Some obscure models, typically older ones, can be purchased from Fender for about $5.

[Jam]

Fender Stage 160 still need help

I replaced D47 and everything worked great for a about a week. Now I when I have the dirty channel on I get a real high picth sound its not feedback but it even does it when you turn the guitar off and the volume on the channel is off it only stops when you when the distortin channel is off