Hello, thank you for that really useful tip. I ran into a no power issue with my G-major and checked everything on the PSU without success, ie the fuse was blowing on plud into AC. I clean the yellow-browny glue on every parts and then magic, it turned back on ! Many thanks Rob !
Hi,
Isn't it typical to see the EMI choke wire linked? I thought only maplins used tio do that to save a few pennies.
regards john
Isn't it typical to see the EMI choke wire linked? I thought only maplins used tio do that to save a few pennies.
regards john
A little update from me, even though it's been almost 6 years since I last posted on this; my TC Electronics PSU is now fixed!
It turned out that R2 (the 150K resistor) was broken after all. I'm not sure why I thought it was ok all those years ago, but it did in fact measure open circuit and with a little help from my dad who happened to have a 150K power resistor the part has been swapped out and the unit now powers up fine! Very happy! 🙂
It seems I was also wrong in a previous post where I thought the resistor started with a violet band, I think that was just a bit of discolouration or something that tricked me into thinking that brown was violet.
So if you have one of these units and it doesn't work I'd suggest carefully checking all of the power resistors in addition to the other suggestions mentioned in this thread. They're probably the easiest part to check anyway.
It turned out that R2 (the 150K resistor) was broken after all. I'm not sure why I thought it was ok all those years ago, but it did in fact measure open circuit and with a little help from my dad who happened to have a 150K power resistor the part has been swapped out and the unit now powers up fine! Very happy! 🙂
It seems I was also wrong in a previous post where I thought the resistor started with a violet band, I think that was just a bit of discolouration or something that tricked me into thinking that brown was violet.
So if you have one of these units and it doesn't work I'd suggest carefully checking all of the power resistors in addition to the other suggestions mentioned in this thread. They're probably the easiest part to check anyway.
Just had one of these power supplies stop working in a TC Electronic D-TWO digital delay.
Three components were faulty. R3 (pink 30K resistor), D13 shottky diode and the Q2 mosfet. I couldn't find an original K2625 so substituted it with STP4NK60ZFP from Mouser, worked fine.
Three components were faulty. R3 (pink 30K resistor), D13 shottky diode and the Q2 mosfet. I couldn't find an original K2625 so substituted it with STP4NK60ZFP from Mouser, worked fine.
Congratulations col ! Glad to hear another successful diy repair has worked.
I started the initial post in the topic in 2013....wow, thats 10 years ago - how time flies! I am sure there are many more with TC- Electroncis psu faults but just aren't aware of the availability of support and information to fix them.
I started the initial post in the topic in 2013....wow, thats 10 years ago - how time flies! I am sure there are many more with TC- Electroncis psu faults but just aren't aware of the availability of support and information to fix them.
The cause of failure was probably the yellow-brown goop used to secure the components around the transformer. As mentioned earlier, as these units get older and the goop breaks down it becomes conductive and shorts out touching components.
I also suspected that! Without a suitable solvent cleanup can be a pain and a potential risk of damaging the pcb or other components.
Hi All
Despite this repair thread being almost 10 years old, I wanted to reply to it as I have just completed my first ever electronics repair and it was this thread that gave me the confidence to have a try. My repair was on a TC Helicon Voiceworks which blew a fuse on the power supply board, literally just out of the blue! Lots of Googling brought me here and I would like to especially thank Nuryev for helping me narrow down the problem area highlighted in his image posted in this discussion. I ended up replacing pretty much everything in that area, although there was only an obvious fault on the MOSFET and one of the diodes. For the small cost, I replaced the power caps even though they measured OK on ESR as they were not too expensive. Buying the ESR meter and the M tester was a few dollars well spent. I am really pleased with this early success and having been able to recover my beloved TCH Voiceworks. Onto my next repair!! 🙂
Once again, a huge thank you to all those in this discussion who helped guide me to the fault. 👍
Despite this repair thread being almost 10 years old, I wanted to reply to it as I have just completed my first ever electronics repair and it was this thread that gave me the confidence to have a try. My repair was on a TC Helicon Voiceworks which blew a fuse on the power supply board, literally just out of the blue! Lots of Googling brought me here and I would like to especially thank Nuryev for helping me narrow down the problem area highlighted in his image posted in this discussion. I ended up replacing pretty much everything in that area, although there was only an obvious fault on the MOSFET and one of the diodes. For the small cost, I replaced the power caps even though they measured OK on ESR as they were not too expensive. Buying the ESR meter and the M tester was a few dollars well spent. I am really pleased with this early success and having been able to recover my beloved TCH Voiceworks. Onto my next repair!! 🙂
Once again, a huge thank you to all those in this discussion who helped guide me to the fault. 👍
Hi Graham,
Congratulations on your successful repair.
It's a good feeling to know that you have saved yourself some money, saved the environment and gained some valuable experience. I am still on the diy road, but have moved on from effects pedals to amplifier repair and more recently a complete Revox a77 reel to reel tape recorder overhaul. My latest project is a Tektronics 2465 Oscilloscope.
I am in Perth WA so if you need any help feel free to drop me a line - be warned though, I have no formal training and most, if not all, of my learning has come from this very site diyAudio. It was the help and support from the very patient and knowledgeable members on diyaudio that has taught me what I know. Enjou your TCH Voiceworks, and good luck with your next repair!
Just remember to unplug before you open, and discharge any large capacitors - take care, stay safe and have fun!
diyAudio enables us to stand on the shoulders of giants - like Nelson Pass, Raymond van Der Steen, Mooly and others to mention a few who have contributed to my learning.
Congratulations on your successful repair.
It's a good feeling to know that you have saved yourself some money, saved the environment and gained some valuable experience. I am still on the diy road, but have moved on from effects pedals to amplifier repair and more recently a complete Revox a77 reel to reel tape recorder overhaul. My latest project is a Tektronics 2465 Oscilloscope.
I am in Perth WA so if you need any help feel free to drop me a line - be warned though, I have no formal training and most, if not all, of my learning has come from this very site diyAudio. It was the help and support from the very patient and knowledgeable members on diyaudio that has taught me what I know. Enjou your TCH Voiceworks, and good luck with your next repair!
Just remember to unplug before you open, and discharge any large capacitors - take care, stay safe and have fun!
diyAudio enables us to stand on the shoulders of giants - like Nelson Pass, Raymond van Der Steen, Mooly and others to mention a few who have contributed to my learning.
Thanks again Nuryev - Good advice on the capacitors. You can never bee too careful. I'd hate to blow up my nice new shiny test gear!!
My next project is a Monitor Audio RXW-12 active subwoofer amp / board that died. I have messaged in a separate thread on DIY Audio for this one. I reached out to Monitor Audio and they were kind enough to share the full schematics with me. This repairing stuff is addictive!
My next project is a Monitor Audio RXW-12 active subwoofer amp / board that died. I have messaged in a separate thread on DIY Audio for this one. I reached out to Monitor Audio and they were kind enough to share the full schematics with me. This repairing stuff is addictive!
The subwoofer plate amps are interesting projects. I have repaired a few and found that there are usually two points of failure.;
1) a resistor in the primary circuit of the power supply close to the AC input
2) a regulator that that is usually in the same vicinity that is prone to overheat and fail.
Look for signs of discolouration - the ceramic resistors can disintegrate when scraped with a metal object.
WARNING! WARNING! WARNING!
Plate amps are usually powered by a SMPS (Switch Mode Power Supply) - if you are a novice to SMPS read, research, read more.. then research more!! They can be extremely dangerous to work on!! Capacitors can still hold a charge for some time even after unplugged from mains power! Be Careful and proceed with caution.
1) a resistor in the primary circuit of the power supply close to the AC input
2) a regulator that that is usually in the same vicinity that is prone to overheat and fail.
Look for signs of discolouration - the ceramic resistors can disintegrate when scraped with a metal object.
WARNING! WARNING! WARNING!
Plate amps are usually powered by a SMPS (Switch Mode Power Supply) - if you are a novice to SMPS read, research, read more.. then research more!! They can be extremely dangerous to work on!! Capacitors can still hold a charge for some time even after unplugged from mains power! Be Careful and proceed with caution.