Question 5153

[crwnedblasphemy]

So back in 2018, my 5153 combo wouldn't light up(front light) or power on/no sound. Power tubes would light up, but nothing once i hit standby. Took it to a licensed fender service tech here and got it fixed. I remember him saying it was an inner fuse. Well, same thing happened to me last night, exact same symptoms...so i pulled the chassis out and looked for that inner fuse. used flashlight and can see this 250v/4amp fuse is blown on the F1 mark of the board going to the power transformer. My question is, does that even need to be there? It's looks like a jerry rig bypass with a fast burn fuse and then got gooped. Just wondering if this is a normal repair, or a half assed way of doing it? Cuz I'm skeptical that this was how it was built originally....and since I didn't pull apart after the 2018 repair, am not sure?

 

[crwnedblasphemy]

Here are a few more pics

 

[311boogieman]

I'm not an amp tech so free bump.

Have you compared to other 5153 gut shots on the web? Maybe the Fender tech did that to protect it like you say. I'd ask 'em. I would also search the amp section of the Fender.com forum as I'm guessing there is discussion about this fuse there. Maybe even a Fender release note.

 

[nevusofota]

Also not an amp tech but it was likely a good thing that it was there. I think a better question is was the fuse the correct value.

 

[crwnedblasphemy]

Also not an amp tech but it was likely a good thing that it was there. I think a better question is was the fuse the correct value.

Think so...As I've said...Haven't had an issue in over 2 years...I had the amp on...Flipped on to warm up...hit standby...played for about 3 minutes...foot pedal wasn't matching up, so flipped power off then back on probably too quickly to fix that(recognize footswitch) and I didn't use the standby switch...causing it to pop/blow. Probably my fault. Just bought some replacement axial fuses and am gonna do the swap myself this tuesday.

 

[crwnedblasphemy]

I'm not an amp tech so free bump.

Have you compared to other 5153 gut shots on the web? Maybe the Fender tech did that to protect it like you say. I'd ask 'em. I would also search the amp section of the Fender.com forum as I'm guessing there is discussion about this fuse there. Maybe even a Fender release note.

I emailed him...also emailed Howard K. Designer. No replies yet from either.

 

[sytharnia1560]

Also not an amp tech but it was likely a good thing that it was there. I think a better question is was the fuse the correct value.

Think so...As I've said...Haven't had an issue in over 2 years...I had the amp on...Flipped on to warm up...hit standby...played for about 3 minutes...foot pedal wasn't matching up, so flipped power off then back on probably too quickly to fix that(recognize footswitch) and I didn't use the standby switch...causing it to pop/blow. Probably my fault. Just bought some replacement axial fuses and am gonna do the swap myself this tuesday.

If the footswitch doesn't link all you need to do is unplug the cable to it and reconnect it..normally works for me

 

[aftec]

That's a horrible job regardless if it is done in the factory (highly not suspected) or not. All fuses should have their double clamped socket for easy change.
I used to have an early version of the 5153 100watter and it has a design flaw, the rectifier diodes are mounted above fet on the other side of the board and that fet can simply burn the traces up on the PCB.

 

[nevusofota]

That's a horrible job regardless if it is done in the factory (highly not suspected) or not. All fuses should have their double clamped socket for easy change.
I used to have an early version of the 5153 100watter and it has a design flaw, the rectifier diodes are mounted above fet on the other side of the board and that fet can simply burn the traces up on the PCB.

But wouldn’t it be safe to say however, after thousands of amps in circulation, that this flaw isn’t much of a flaw after all?

 

[splatter]

that is a rigged POS. I no longer own a 5153 and all I did was swap tubes and rebias when I had it open but I can tell you from the way that looks . IT AIN'T FACTORY

 

[aftec]

That's a horrible job regardless if it is done in the factory (highly not suspected) or not. All fuses should have their double clamped socket for easy change.
I used to have an early version of the 5153 100watter and it has a design flaw, the rectifier diodes are mounted above fet on the other side of the board and that fet can simply burn the traces up on the PCB.

But wouldn’t it be safe to say however, after thousands of amps in circulation, that this flaw isn’t much of a flaw after all?

I don't know if this is a regular issue with these very early 5153s or my FET was overheating for some reason. I checked the photos of this amp and those fets are sitting on a hute piece of metal in the combo version acting as a heatsink. It's that bolted piece of metal at the top of the PCB with 2 FETS on it.

 

[crwnedblasphemy]

that is a rigged POS. I no longer own a 5153 and all I did was swap tubes and rebias when I had it open but I can tell you from the way that looks . IT AIN'T FACTORY

I was betting it wasn't...I've never seen a fused internally wired like that stock.

 

[crwnedblasphemy]

Also not an amp tech but it was likely a good thing that it was there. I think a better question is was the fuse the correct value.

Think so...As I've said...Haven't had an issue in over 2 years...I had the amp on...Flipped on to warm up...hit standby...played for about 3 minutes...foot pedal wasn't matching up, so flipped power off then back on probably too quickly to fix that(recognize footswitch) and I didn't use the standby switch...causing it to pop/blow. Probably my fault. Just bought some replacement axial fuses and am gonna do the swap myself this tuesday.

If the footswitch doesn't link all you need to do is unplug the cable to it and reconnect it..normally works for me

Usually you have to have it plugged in before turning on to avoid an issue.