Hi Stuart, thanks for the video. I had this exact problem on my amp. I had a local shop raise the resisters and repair the wire like in your video. They charged my about $500 Candian for the repair and I had to wait months to get the amp back. As no good deed goes unpunished, our local band was opening for a touring act and at showtime the headliners guitar amp was acting up so he used my for the show. They had another couple of shows after on the road before coming back by our town again on their way home so I let him take my amp and as luck would have it, the channel selection was not working when he returned it. I watched the video, opened it up and sure enough one of the capacitors had come loose. So this time I imitated your repair and saved myself months of waiting and hundreds of dollars. Thanks a million Stuart!
Hi Michael. You've made my day because this is exactly why I do these videos (apart from the drugs, the girls and the sacks of cash of course...) Wow, you were seriously ripped off at $500. I would charge about $100 Canaadian for that!
I am delighted to have the amp working again! Great job Stuart and thanks for the detailed vid - very interesting. This is the most popular amp for rehearsal and recording at the studio, so yes, it's seen the occasional spillage and mistreatment. Well loved otherwise! Great tip on that 12AY7 valve to reign in the volume - will do that, as it's unbearably loud beyond 2-3! To be clear - the previous 2 services did initially solve the channel switching problem, but it soon went faulty again. Hopefully not this time! Will be back with any future service needs. Mike - Safehouse Studio
This is very helpful, thanks. I've got one on the bench with similar issues. I think the reason other techs haven't been able to fix is because they just knew to not touch these with a barge pole :)) You we're right moaning about Fender. What a mess!
Excellent repair, it's hard to believe that a ( couple) other ppl looked at this and couldn't figure it out.mind boggling to say the least, makes one wonder if they had even looked at it, but great job none the less,one repaired amp, another satisfied customer, a little bit of ching in the kettle, win win..
Yes I do wonder sometimes how much detailed investigation gets done. Quite often it's a 'service' (whatever that means) and a bill for £150 or whatever!
It turned out to be easy… I replaced the 470 ohm 5 watt resistors with some space off the board but I also had to repair damaged traces on the underside of the pcb… The amp had been repaired before and the traces were already long gone replaced with wire. The whole are was heavily burnt. One if the 470 ohm resistors had snapped off due to vibration. It’s back in action now. Thanks for replying 😁
@@stuartukguitarampguy5830 finally I had the time to fix my Amp and it's working again very well. Additionally I"ve added an aluminium heatsink on every of the two 470 ohm resistors. THANKS once more for all your outstanding videos.
hi, thanx for the infos, although i would recommend to lift that zeners up if i already install a new one.. ???? otherwise it will do the same fault/heat again later on.
I do not understand why you did not remove the other one and mount them OFF THE BOARD so the destruction does not continue to happen? Was there a reason as too why that I might have missed....
I'm 50/50 on that. It's hard to get them mounted off the board AND stable to they don't flap around. I've literally just finished another one today and I've made a sort of heatsink arrangement for the two reistors. What's your off board mounting solution? (Keeping them mechanically stable too).
Did you drain the filter caps? I check that before I put a finger or screwdriver in there. Might avoid ruining anything extra. Wow that was an extreme risk to power up th amp board leaning up agains the chassis. Otherwise a very helpful video. Thank you.
There is an amp for sale but states amp turns on and works. But will randomly change channels and effects randomly. Would this fix be the answer to the amps problem. Or would you know the cause.
It's a toss up between Standing it off for better heat flow, but risking a dry joint as the resistor can now move (as the amp is moved around, bumped etc) -v- slightly worse heatflow but having the resistor stable. I usually go for the former. Stuart
A defective 4560 (U3) Operational amp was the culprit in another unit that I worked on +16v was getting loaded down due to internal short in the IC. FYI
I always explicitly ask if the owner wants their gear cleaned. Some owners want to keep the dirt and grime on their gear because of the "road worn" look.
Hi, Stuart, Well I’m fighting for a longtime now with the channel switching issue. I changed the 470 ohms resistors, the zener diode, the relay… When the foot switch is plug, there is no issue. Once unplugged I get the switch channel issue. When the HRD is running for a longtime the issue disappear. I became crazy !!!. Any Advices or things to check ? Thks 😉
SO it's the front channel switch which is the issue? SOunds like when the amp gets hot, it cures itself. That points to maybe a bad joint. Very hard to say without seeing it.
Thanks for your quick answer Stuart, appreciate, I would love to bring my HRD to your shop. But I’m living in France !!! I’ll recheck all the connections point again… The Pcb is damaged too, I’ve rebuild some of them.
Anytime I find the scorched resistors I change them out for the Marshall style with the tall legs. It keeps the heat away from the board and extends the life of all the components. I know some guys like to just use long leads from normal ceramic resistors, but I don't think it has the strength to support the resistor when the musician is banging the amp around during a load out.
@@stuartukguitarampguy5830 true. Keeping inventory is difficult because there's so many different components and most of them you're never going to need. And inventory equals money tied up. I have the most common parts stocked and some odds and ends, but mostly I always end up having to order something for the customer anyways. Its a lucky day in which I have everything in-house- in fact that is usually so rare that when it happens I question what it is that I am overlooking.
great job, but, it would have been nice to see you clean all the old flux from the solder joints from previous repair and maybe lift the resistors off the board slightly to stop burning thru the board
Agreed. I'll probaby do that next time. There's a slight downside of lifting the resistors as they can now wobble around and could eventually become desoldered.
I'm having issues but its with the footswitch, not the switches on the amp itself. Any ideas? It basically stays in overdrive when the switch is connected, but the switch appears to work, reverb will switch on and off and the lights come on and off too.
@@stuartukguitarampguy5830 I believe it might be because I've got a 3 switch footswitch, apparently these have only 2 switches, there isn't supposed to be one for reverb, does that make sense?
At 4:00: this is exactly why lead-free solder sucks! It never wets to the component leads as well as lead solder does, and lead-free crystallizes and turns crumbly wherever it's exposed to heat, much faster and sooner than leaded solder would. Lead free solder certainly does not belong in a tube amp, nor should it be used on hot-running power supply components like big resistors and high-wattage diodes.
@@stuartukguitarampguy5830 , personally, instead of laying the resistor down flat so it could continue to bake the board, drying out the solder and causing foil traces to come undone from the board, I would have stood them up straight on one end (extending the topmost lead if need be to reach through the board), securing them against vibrating with high-temp silicone RTV. And, instead of using a separate wire to repair the broken foil trace, if you stood the resistors on end the full length of one component lead of each resistor coming through the board could be bent over and secured to the solder joint of the next component, giving the resistor "a good leg to stand on"! As it stands, they'll just continue to bake that area of the board (possibly causing the foils to unbound from the board); ditto for the large diode, that too could be stood on end.
@@stuartukguitarampguy5830 , did you not replace the two caps next to the hot resistors? They'll fail sooner rather than later; if they filter the relay supply, well, relay coils work a lot better on DC than on AC ripple, and I am guessing that the +/- 15v is also used for something else, like effects IC's perhaps? Also, if the board-mounting screws didn't include toothed star washers, I would have added them to prevent the screws from vibrating loose. A free-floating screw can do a lot of damage in a circuit with 400+ volts!
Hi Tim You only need insulation if the wire routing could possibly cause a short. In this case it couldn't so TC wire is fine. For example I always use TC wire when repairing a pcb trace.
At 7:15, you really should use a socket wrench or nut driver handle to remove the nuts from the controls. Its "bad form" to use an adjustable wrench, and can scratch the faceplate.
@@stuartukguitarampguy5830 , I won't say I haven't done it ---- if you're doing a service call to the club or someone's home and don't have the right socket, sure; but at the shop one is presumed to have the correct tool on the bench or in the tool chest! On my bench, I have a set of 3 "Hozan" sockets, double-ended deep sockets with a built-in, foldaway handle/break-free lever in the middle; 9/10, 11/12, and 13/14 millimeter sizes that cover most repair needs for removing control-shaft nuts. I was using these back in the 1980s when I was a car-stereo installer! Still available, as far as I know; some other company now makes a similar product out of high-impact plastic, I've seen other amp-repair guys on You Tube using them but I can't remember the name of the tool or the company. When I worked as a telecom and data-cable installer, we all had a cross shaped, heavily-cast 4-way socket wrench that if you'd put a chain on it and hung it around your neck you'd have looked like Ozzy Osbourne!
@@goodun2974 Ha ha! Nice one. I can just see you walking around with that on your neck! I'd be interested in those hi impact plastic versions. I'll see if I can find them.
@@stuartukguitarampguy5830 , Brad the Guitologist featured them on his YT channel, but I unsubbed because there was just too much non-repair-related drama and Q-inspired ranting. Anyway, I can't remember the name of the plastic sockets but I'll try to search for them....they had a clever, cute name which I can't remember (and a quick Google search didn't turn up anything). Hozan tools, however, are still available; from electronics to bike repair and industrial maintenance, they make many hugh-quality special purpose tools and kits.
@@stuartukguitarampguy5830 , Another socket-related tool-tip for replacing shaft nuts and such is to modify a deep socket by epoxy-gluing a shaft nut inside the socket, about 1/4" at most, or a bit less(4 to 6 mm or so) past the mouth of the socket, and reaming out the hole in the middle of the shaft nut (after the epoxy is well cured), sufficiently to remove the internal threads from the glued-in shaft nut. When reassembling a piece of equipment,, you can drop a shaft nut into the socket and it'll pretty much stay in place even if you need to hold the socket in a horizontal position, and you can start the nut threading onto the pot shaft without having to use needle nose pliers or your fingers. Perhaps not as necessary for most guitar amps, but old hifi gear and antique radios often have the pot shafts recessed into a well or tunnel on the escutcheon, and while its easy to remove them its not so easy to get the threads started when your fingers won't fit in there! I got tired of fumbling with needle nose pliers or Hemostats, and sometimes cross-threading the shaft nuts, so I made a set of specially modified sockets just for this purpose. (JB Weld epoxy worked well for this, BTW).
I always take those resistors out so they stop burning the board. Add wires to the pads if they’re not yet destroyed, and attach to panel mount resistors screwed into the chassis.
Thanks Alva, good tip. My problem is always money though. My customers are quite price sensitive. They don't mind paying, say, £45 for a repair but if I then start doing all srts of precautionary mods and hand a bill for £125 or whatever, that's way too much for them. Also, 90% of the amps I do are not gig-critical - it's just people playing at home. So it's not really that serious if another problem arises in a year or two. They can just bring the amp back to me to get it fixed.
People are always bitching to me about my adjustable wrench! I use it all the time and it's an excellent tool for pot nuts etc. Never once made a mistake with it in thousands of amps!
The only way to repair these amps And I’ve done so many I’ve lost count, is to install a aluminium angle, bolted to the existing transformer holes. This allows for some 10watt chassis mount resistors to bolt to angle bracket. This fits nicely between both boards, and removes the heat from the PCB. I’ve seen techs put heat sinks on the the resistors. Which complete rubbish in a enclosed compartment. With the chassis mount resistors there is enough mass in the aluminium bracket bolted to the chassis to remove the heat.
Just replaced the 470ohm resistors in my hrd as board burning. New ones fitted but no drive channel or reverb. The copper trace around the component hole came of board easy. Will never buy a fender amp again.
@stuartukguitarampguy5830 i used copper wire to go point to point. The overdrive light didnt go red, discovered dry joint on board where light wires go. All working now. Posted videos of repair on my channel. Marshall have the power resistors off the board, so why dont fender!
I have one on the bench now that has similar problem I've never encountered. light switches from off to green to red, but amp always stays on dirty channel. It does add the "more drive" gain but no clean channel at all... anyone experienced this before?
Fairly baffled that you did not correct the heat on the board issue with length. Also not crazy about the exposed wire facing the chasis in the trace repair. Living dangerously.
There's also exposed conductive solder joints not much further away than the wire repair, and nobody cares about those. There's standoffs on the chassis giving plenty of room.
Stuart, I think amplifier manufacturers should canvass amp techs and get their feedback about the repairability and functionality of their products. So we can get rid of these overtly technical amps.
Hi Patrick. My view is that they care almost nothing about repairability. It adds zero to their bottom line. If the choice is saving 10c on costs or making it slightly easier to repair, they'll save the 10c every time.
The two resistors should not be so close to the board… the problem is only fixed temporary. The board will get warm because the resistors are not elevated from the board.
God I am Old Young Stuart! I HATE all these horrible Circus board newish so called Fenders!.Sorry just don't sound good to my old ears. I'll stick with my 1976 Musicman 2x10 65! Which is a proper (Leo) amp!! (Yes Co co will be fine Matron! Thank you!)
I hear you but actually the HotRod Deluxe and similar are actually cracking amps. The only problem is a handful of build isues which make them a bit unreliable.
Hi Stuart, thanks for the video. I had this exact problem on my amp. I had a local shop raise the resisters and repair the wire like in your video. They charged my about $500 Candian for the repair and I had to wait months to get the amp back.
As no good deed goes unpunished, our local band was opening for a touring act and at showtime the headliners guitar amp was acting up so he used my for the show. They had another couple of shows after on the road before coming back by our town again on their way home so I let him take my amp and as luck would have it, the channel selection was not working when he returned it. I watched the video, opened it up and sure enough one of the capacitors had come loose. So this time I imitated your repair and saved myself months of waiting and hundreds of dollars. Thanks a million Stuart!
Hi Michael. You've made my day because this is exactly why I do these videos (apart from the drugs, the girls and the sacks of cash of course...) Wow, you were seriously ripped off at $500. I would charge about $100 Canaadian for that!
I am delighted to have the amp working again! Great job Stuart and thanks for the detailed vid - very interesting. This is the most popular amp for rehearsal and recording at the studio, so yes, it's seen the occasional spillage and mistreatment. Well loved otherwise! Great tip on that 12AY7 valve to reign in the volume - will do that, as it's unbearably loud beyond 2-3! To be clear - the previous 2 services did initially solve the channel switching problem, but it soon went faulty again. Hopefully not this time! Will be back with any future service needs. Mike - Safehouse Studio
Thanks Mike.
This is very helpful, thanks. I've got one on the bench with similar issues. I think the reason other techs haven't been able to fix is because they just knew to not touch these with a barge pole :)) You we're right moaning about Fender. What a mess!
Good luck fixing it. If it's channel switching it's likely to be the zeners.
Excellent repair, it's hard to believe that a ( couple) other ppl looked at this and couldn't figure it out.mind boggling to say the least, makes one wonder if they had even looked at it, but great job none the less,one repaired amp, another satisfied customer, a little bit of ching in the kettle, win win..
Yes I do wonder sometimes how much detailed investigation gets done. Quite often it's a 'service' (whatever that means) and a bill for £150 or whatever!
john salaman - I repair amps in New York and also surprised *two* previous techs didn’t notice the scorched board 🤷🏽♂️
@@cirenosnor5768 Did they even open it!
Nice job on the repair, Stuart!
Thanks Michael!
Thanks for making this video, I have one of these to look at and it turns out it has exactly this problem...
I hope you manage to get it fixed.
It turned out to be easy… I replaced the 470 ohm 5 watt resistors with some space off the board but I also had to repair damaged traces on the underside of the pcb… The amp had been repaired before and the traces were already long gone replaced with wire. The whole are was heavily burnt. One if the 470 ohm resistors had snapped off due to vibration. It’s back in action now. Thanks for replying 😁
@@cameronwalter997 Excellent well done
Nicely done. Good repair Stuart cheers matey
Thank you very much for this very informative video. I have exactly the same problem on my Fender Hot Rod. Greetings from Switzerland🇨🇭
I hope it helped! All the best from rainy England.
@@stuartukguitarampguy5830 finally I had the time to fix my Amp and it's working again very well. Additionally I"ve added an aluminium heatsink on every of the two 470 ohm resistors.
THANKS once more for all your outstanding videos.
@@BACKBONEhardrock Excellent, well done.
Thank you very much for video, saved me a headache.
Excellent that's exactly why I produce them.
Thank you sir for great video helpful
Thanks Raymond
I've seen some repair videos on UA-cam on the Hot Rod Deluxe where they extend out the resistors so there's not as much heat burning the board.
Yes that's a good idea and I do that sometimes.
hi, thanx for the infos,
although i would recommend to lift that zeners up if i already install a new one..
????
otherwise it will do the same fault/heat again later on.
Yes good thinking but they would have to be replaced as the leads are too short for them to be lifted.
I do not understand why you did not remove the other one and mount them OFF THE BOARD so the destruction does not continue to happen? Was there a reason as too why that I might have missed....
I'm 50/50 on that. It's hard to get them mounted off the board AND stable to they don't flap around. I've literally just finished another one today and I've made a sort of heatsink arrangement for the two reistors. What's your off board mounting solution? (Keeping them mechanically stable too).
Great job this is good too know guess I won’t pass on these for cheap anymore.
Did you drain the filter caps? I check that before I put a finger or screwdriver in there. Might avoid ruining anything extra. Wow that was an extreme risk to power up th amp board leaning up agains the chassis. Otherwise a very helpful video. Thank you.
Hi Christian Yes I always do that. 3,000 amps and still alive...
Can anything be done to lift the power resistors off the board. Longer legs or some of that silicone padding ??
Yes you can do that. Not easy though. PAdding tends to heat insulate the underside.
what type of cable do you use to make the bridge?
There is an amp for sale but states amp turns on and works. But will randomly change channels and effects randomly. Would this fix be the answer to the amps problem. Or would you know the cause.
Why is it necessary to scrape the track before making the bridge?
Just ordinary tinned copper wire. Scrape the resist off the track otherwise you can;t solder to it!
Why did you put the new resistor hard down on the board again?
It's a toss up between Standing it off for better heat flow, but risking a dry joint as the resistor can now move (as the amp is moved around, bumped etc)
-v- slightly worse heatflow but having the resistor stable. I usually go for the former. Stuart
A defective 4560 (U3) Operational amp was the culprit in another unit that I worked on +16v was getting loaded down due to internal short in the IC. FYI
Ah interesting. Yes I've known dual op amps like the 1458 to go down many times.
I always explicitly ask if the owner wants their gear cleaned. Some owners want to keep the dirt and grime on their gear because of the "road worn" look.
Yes I'm very mindful of that too! I have amps back after several years which still have my 'luggage tag' job number label atached!
Hi, Stuart, Well I’m fighting for a longtime now with the channel switching issue. I changed the 470 ohms resistors, the zener diode, the relay… When the foot switch is plug, there is no issue. Once unplugged I get the switch channel issue. When the HRD is running for a longtime the issue disappear. I became crazy !!!. Any Advices or things to check ? Thks 😉
SO it's the front channel switch which is the issue? SOunds like when the amp gets hot, it cures itself. That points to maybe a bad joint. Very hard to say without seeing it.
Thanks for your quick answer Stuart, appreciate, I would love to bring my HRD to your shop. But I’m living in France !!! I’ll recheck all the connections point again… The Pcb is damaged too, I’ve rebuild some of them.
Anytime I find the scorched resistors I change them out for the Marshall style with the tall legs. It keeps the heat away from the board and extends the life of all the components. I know some guys like to just use long leads from normal ceramic resistors, but I don't think it has the strength to support the resistor when the musician is banging the amp around during a load out.
Good tip, thanks. Bit of a pain though to have to stock all the values of Marshall-style power resistors.
@@stuartukguitarampguy5830 true. Keeping inventory is difficult because there's so many different components and most of them you're never going to need. And inventory equals money tied up. I have the most common parts stocked and some odds and ends, but mostly I always end up having to order something for the customer anyways. Its a lucky day in which I have everything in-house- in fact that is usually so rare that when it happens I question what it is that I am overlooking.
Thank you
Hey Stuart. Need some help. My hot Rod devile switch Chanel stays on and na change. What should I do. Please
Off the top of my head it will either be the zeners producing the 15V supply, or a stuck relay.
great job, but, it would have been nice to see you clean all the old flux from the solder joints from previous repair and maybe lift the resistors off the board slightly to stop burning thru the board
Agreed. I'll probaby do that next time. There's a slight downside of lifting the resistors as they can now wobble around and could eventually become desoldered.
I'm having issues but its with the footswitch, not the switches on the amp itself. Any ideas? It basically stays in overdrive when the switch is connected, but the switch appears to work, reverb will switch on and off and the lights come on and off too.
Hard to diagnose over the net without seeing it. I hope you manage to get it sorted.
@@stuartukguitarampguy5830 I believe it might be because I've got a 3 switch footswitch, apparently these have only 2 switches, there isn't supposed to be one for reverb, does that make sense?
@@nzoomed Yes that sounds correct
A shorted CR28 (D28) 10V Zener diode was the culprit with a Hot Rod Deluxe I recently serviced. FYI
Many thanks. Yes I've had that too.
At 4:00: this is exactly why lead-free solder sucks! It never wets to the component leads as well as lead solder does, and lead-free crystallizes and turns crumbly wherever it's exposed to heat, much faster and sooner than leaded solder would. Lead free solder certainly does not belong in a tube amp, nor should it be used on hot-running power supply components like big resistors and high-wattage diodes.
Agreed. I never use lead-free solder! Can't stand the stuff.
@@stuartukguitarampguy5830 , personally, instead of laying the resistor down flat so it could continue to bake the board, drying out the solder and causing foil traces to come undone from the board, I would have stood them up straight on one end (extending the topmost lead if need be to reach through the board), securing them against vibrating with high-temp silicone RTV. And, instead of using a separate wire to repair the broken foil trace, if you stood the resistors on end the full length of one component lead of each resistor coming through the board could be bent over and secured to the solder joint of the next component, giving the resistor "a good leg to stand on"! As it stands, they'll just continue to bake that area of the board (possibly causing the foils to unbound from the board); ditto for the large diode, that too could be stood on end.
@@goodun2974 Good tips thanks.
@@stuartukguitarampguy5830 , did you not replace the two caps next to the hot resistors? They'll fail sooner rather than later; if they filter the relay supply, well, relay coils work a lot better on DC than on AC ripple, and I am guessing that the +/- 15v is also used for something else, like effects IC's perhaps? Also, if the board-mounting screws didn't include toothed star washers, I would have added them to prevent the screws from vibrating loose. A free-floating screw can do a lot of damage in a circuit with 400+ volts!
Why didn’t you use a piece of wire or use shrink wrap on than bare wire?
Hi Tim You only need insulation if the wire routing could possibly cause a short. In this case it couldn't so TC wire is fine. For example I always use TC wire when repairing a pcb trace.
THANKS!
At 7:15, you really should use a socket wrench or nut driver handle to remove the nuts from the controls. Its "bad form" to use an adjustable wrench, and can scratch the faceplate.
True but I've removed many thousand of nuts using my adjustable and never once marked the faceplate. I have a delicate touch!!
@@stuartukguitarampguy5830 , I won't say I haven't done it ---- if you're doing a service call to the club or someone's home and don't have the right socket, sure; but at the shop one is presumed to have the correct tool on the bench or in the tool chest! On my bench, I have a set of 3 "Hozan" sockets, double-ended deep sockets with a built-in, foldaway handle/break-free lever in the middle; 9/10, 11/12, and 13/14 millimeter sizes that cover most repair needs for removing control-shaft nuts. I was using these back in the 1980s when I was a car-stereo installer! Still available, as far as I know; some other company now makes a similar product out of high-impact plastic, I've seen other amp-repair guys on You Tube using them but I can't remember the name of the tool or the company. When I worked as a telecom and data-cable installer, we all had a cross shaped, heavily-cast 4-way socket wrench that if you'd put a chain on it and hung it around your neck you'd have looked like Ozzy Osbourne!
@@goodun2974 Ha ha! Nice one. I can just see you walking around with that on your neck! I'd be interested in those hi impact plastic versions. I'll see if I can find them.
@@stuartukguitarampguy5830 , Brad the Guitologist featured them on his YT channel, but I unsubbed because there was just too much non-repair-related drama and Q-inspired ranting. Anyway, I can't remember the name of the plastic sockets but I'll try to search for them....they had a clever, cute name which I can't remember (and a quick Google search didn't turn up anything). Hozan tools, however, are still available; from electronics to bike repair and industrial maintenance, they make many hugh-quality special purpose tools and kits.
@@stuartukguitarampguy5830 , Another socket-related tool-tip for replacing shaft nuts and such is to modify a deep socket by epoxy-gluing a shaft nut inside the socket, about 1/4" at most, or a bit less(4 to 6 mm or so) past the mouth of the socket, and reaming out the hole in the middle of the shaft nut (after the epoxy is well cured), sufficiently to remove the internal threads from the glued-in shaft nut. When reassembling a piece of equipment,, you can drop a shaft nut into the socket and it'll pretty much stay in place even if you need to hold the socket in a horizontal position, and you can start the nut threading onto the pot shaft without having to use needle nose pliers or your fingers. Perhaps not as necessary for most guitar amps, but old hifi gear and antique radios often have the pot shafts recessed into a well or tunnel on the escutcheon, and while its easy to remove them its not so easy to get the threads started when your fingers won't fit in there! I got tired of fumbling with needle nose pliers or Hemostats, and sometimes cross-threading the shaft nuts, so I made a set of specially modified sockets just for this purpose. (JB Weld epoxy worked well for this, BTW).
I always take those resistors out so they stop burning the board. Add wires to the pads if they’re not yet destroyed, and attach to panel mount resistors screwed into the chassis.
Thanks Alva, good tip. My problem is always money though. My customers are quite price sensitive. They don't mind paying, say, £45 for a repair but if I then start doing all srts of precautionary mods and hand a bill for £125 or whatever, that's way too much for them. Also, 90% of the amps I do are not gig-critical - it's just people playing at home. So it's not really that serious if another problem arises in a year or two. They can just bring the amp back to me to get it fixed.
@@stuartukguitarampguy5830 I see your point. I often struggle with the "what should be done" vs "what has to be done right now".
bodging with an adjustable wrench?
People are always bitching to me about my adjustable wrench! I use it all the time and it's an excellent tool for pot nuts etc. Never once made a mistake with it in thousands of amps!
Is there another reason why this happens?
Probably! I expect there are many reasons.
The only way to repair these amps
And I’ve done so many I’ve lost count, is to install a aluminium angle, bolted to the existing transformer holes. This allows for some 10watt chassis mount resistors to bolt to angle bracket.
This fits nicely between both boards, and removes the heat from the PCB. I’ve seen techs put heat sinks on the the resistors. Which complete rubbish in a enclosed compartment. With the chassis mount resistors there is enough mass in the aluminium bracket bolted to the chassis to remove the heat.
Ok I've made a mental note of that thanks.
Just replaced the 470ohm resistors in my hrd as board burning. New ones fitted but no drive channel or reverb. The copper trace around the component hole came of board easy. Will never buy a fender amp again.
Yes it's not good is it!
@stuartukguitarampguy5830 i used copper wire to go point to point. The overdrive light didnt go red, discovered dry joint on board where light wires go. All working now. Posted videos of repair on my channel.
Marshall have the power resistors off the board, so why dont fender!
Exactly! That whole area is a mess!
I have one on the bench now that has similar problem I've never encountered. light switches from off to green to red, but amp always stays on dirty channel. It does add the "more drive" gain but no clean channel at all... anyone experienced this before?
I haven't had that. It could be a relay issue?
The best method is to raise those resistors off the board giving a bit of air space for cooling. Badly engineered design from the start.
And they eve thought that mounting those 5 watters upside down would solve the heat problem!!!🤣🤣🤐🤐🧐🧐
You should have left a gap between the board and the white resistors.
Fairly baffled that you did not correct the heat on the board issue with length. Also not crazy about the exposed wire facing the chasis in the trace repair. Living dangerously.
There's also exposed conductive solder joints not much further away than the wire repair, and nobody cares about those. There's standoffs on the chassis giving plenty of room.
Stuart, I think amplifier manufacturers should canvass amp techs and get their feedback about the repairability and functionality of their products. So we can get rid of these overtly technical amps.
Hi Patrick. My view is that they care almost nothing about repairability. It adds zero to their bottom line. If the choice is saving 10c on costs or making it slightly easier to repair, they'll save the 10c every time.
Lovely, a very much deserved berating of an American company by an English gentleman, fantastic ;).
The two resistors should not be so close to the board… the problem is only fixed temporary. The board will get warm because the resistors are not elevated from the board.
Yep, bad design.
If I'm buying a used one of these Fender HotRods I'm asking the seller for pictures of the insides.
Good idea. They're great amps but they suffer from a small handful of common issues, all easily rectified fortunately.
God I am Old Young Stuart! I HATE all these horrible Circus board newish so called Fenders!.Sorry just don't sound good to my old ears. I'll stick with my 1976 Musicman 2x10 65! Which is a proper (Leo) amp!! (Yes Co co will be fine Matron! Thank you!)
I hear you but actually the HotRod Deluxe and similar are actually cracking amps. The only problem is a handful of build isues which make them a bit unreliable.