FS - Fender HRD - Needs repair - £150

MatthewShreddery

Just putting this out there to gauge interest.
Has the common fault where it randomly switches channels.
Had a quick look inside - the usual heat related damage in the usual areas.

1x12 fender speaker.
I think it's an earlier model - Mk1 maybe 2..? (will check later)
Made in Mexico

It sounds fantastic, and generally works well - I use a patch cable partially inserted into the foot switch jack socket and that mostly removes the switching problem.

I'm confident this amp can be repaired at a reasonable cost - I just can't really be bothered with sorting that out and would rather just cut my losses.

Based in Portsmouth/Leicester. 
Probably not going to put this in the post.

https://i.imgur.com/L1YxoYi.jpg
https://i.imgur.com/Xcee5e5.jpg
https://i.imgur.com/cU9ggxM.jpg
https://i.imgur.com/ygjhUcF.jpg

MatthewShreddery

Bump 

MatthewShreddery

Bump

MatthewShreddery

Had zero interest in this which surprises me a bit.

4on6

Hi mate... if I hadn’t just said yes to another amp I would have been very interested...
I wasn’t aware this was a common problem.. so perhaps a bit more detail on likely fix and prognosis... if you can get someone like ICBM to comment (maybe in the “Amps” section rather than for sale?.. that may assure people a bit??

Danny1969

It’s not a difficult thing to fix it’s basically re-soldering two large resistors on the PCB
I would take it myself just to flip it but I’m simply too busy at the minute repair wise to take on anything else. 
If it’s still about in a couple of weeks though I will definitely have it

MatthewShreddery

Cheers dudes - don't mean to sound like I'm whinging BTW!

MatthewShreddery

Buuuuuump! 

ICBM

It's a MkII, if that helps.

The problem is probably not the two large 'box' ceramic resistors, but the smaller cylindrical one almost directly below the footswitch socket. You will have to get at the back side of the PCB to fix it, but not too difficult if you know what you're doing.

MatthewShreddery

ICBM said:

It's a MkII, if that helps.

The problem is probably not the two large 'box' ceramic resistors, but the smaller cylindrical one almost directly below the footswitch socket. You will have to get at the back side of the PCB to fix it, but not too difficult if you know what you're doing.

Thanks as ever.
Is it likely that the resistor will need replacing, or just resoldering? 

mrn1989

I'd take but too far for me, I'm based in Bucks

Gilly

Pm sent. I’m interested if it can be made to stay on the clean channel?

mrn1989

Gilly said:

Pm sent. I’m interested if it can be made to stay on the clean channel?

It will need repair, running it as it is could cause real damage, potentially fire if its due to resistors overheating, which is commonly the cause

MatthewShreddery

I may just fix this myself as I have some time off soon.
Watch this space - if interested Pm me

ICBM

MatthewShreddery said:

Is it likely that the resistor will need replacing, or just resoldering? 

Just resoldering.

mrn1989 said:

It will need repair, running it as it is could cause real damage, potentially fire if its due to resistors overheating, which is commonly the cause

Sorry, this is nonsense.

The resistors do overheat, but only just enough to cook the solder joints over a *very* long period, and slowly turn the board brown. There is no fire risk whatever.

(Unlike the Blues Junior, which does have a genuine risk of more serious burning due to a completely different cause - high-voltage arcing on the valve PCB - but is still highly unlikely to actually be a fire risk outside the amp.)

mrn1989

mrn1989 said:

It will need repair, running it as it is could cause real damage, potentially fire if its due to resistors overheating, which is commonly the cause

Sorry, this is nonsense.

The resistors do overheat, but only just enough to cook the solder joints over a *very* long period, and slowly turn the board brown. There is no fire risk whatever.

(Unlike the Blues Junior, which does have a genuine risk of more serious burning due to a completely different cause - high-voltage arcing on the valve PCB - but is still highly unlikely to actually be a fire risk outside the amp.)

Just going by what my tech told me when I asked if he'd dealt with this issue before and if he'd be up for the task. He also said sustained use left as is with burnt resistors and no repair could damage other components from excess current flow. It's a simple fix and he said it takes more time to pull the board out than it does to replace parts.

He sent me an image and said it will almost certainly look something like this

https://i.imgur.com/fzydATB.png

Philtre

Would this resistor problem be less likely if the amp had been set to run at 240v?

ICBM

mrn1989 said:

Just going by what my tech told me when I asked if he'd dealt with this issue before and if he'd be up for the task. He also said sustained use left as is with burnt resistors and no repair could damage other components from excess current flow. It's a simple fix and he said it takes more time to pull the board out than it does to replace parts. 

He sent me an image and said it will almost certainly look something like this

That's typical of any HRD that's been used for long enough - but there is no fire risk, and no particular hazard to other parts since no extra current will flow.

The diodes CR13 and CR14 also run very hot, and if they desolder themselves that *can* blow other parts.

Philtre said:

Would this resistor problem be less likely if the amp had been set to run at 240v?

Yes. Those resistors are the most affected by the supply voltage since the output end of them - to the diodes - is a fixed voltage, which means that when the input voltage is raised, the voltage drop across them and hence the heating is increased.


For amusement, this is what the result of a Blues Junior arc can look like! I've never seen one actually set fire to the amp though.

mrn1989

That looks like my girlfriends toast, yikes! lol

LastMantra

I'd have had a go but I'm In Scotland 

Good luck whatever you do 

MatthewShreddery

Bump