I sometimes have access to dead mother boards and computer power supplies and I am wondering if the caps, or any other parts are good for audio use.
I tend to think that the film caps rated at 400v can be used as bypass. Also the electro caps are 105 degrees and my logic says that they must be good then, but again I'm not sure.
Are these worth the time desoldering these things or I better just dump them in the bin?
I tend to think that the film caps rated at 400v can be used as bypass. Also the electro caps are 105 degrees and my logic says that they must be good then, but again I'm not sure.
Are these worth the time desoldering these things or I better just dump them in the bin?
Lately because of the cost of living, all my friends and family know that instead of sending old or broken Computers VCR etc to the dump to pass them on to me.
I found that it doesn't take long to pull the main board etc from a monitor or computer, so I don't see the problem.
What I do is set the soldering Iron up next to the couch, make a cup of coffee and while I am watching TV I Take my time and desolder everything I want and before you know it your moving on to the next board. Also I set up shelves in the shed just for boards I haven't done yet. I would rather spend time on the couch with my family desoldering then at work to get the money to buy new components.
I found that it doesn't take long to pull the main board etc from a monitor or computer, so I don't see the problem.
What I do is set the soldering Iron up next to the couch, make a cup of coffee and while I am watching TV I Take my time and desolder everything I want and before you know it your moving on to the next board. Also I set up shelves in the shed just for boards I haven't done yet. I would rather spend time on the couch with my family desoldering then at work to get the money to buy new components.
Computers have all kinds of parts to salvage.
The Powersupply, has HV caps, along with other goodies. Also contains several transistors, resistors, and the small heatsinks are good for putting on hot transistors or rectifier in an audio project.
Computer Monitors are even better. The circuit that plugs on the back of the CRT has HV transistors in sets of 3 for RGB and sometimes complementary pairs too. Also you will find a few good high wattage resistors and HV caps there too. My amp uses 150V transistors in the LTP and CCS taken from computer monitor. I also got a bunch of trimmer POTS from various monitors. You can never have enough trimmer pots.
Also lots 1/4W and 1/2W resistors in somewhat standard values can be found.
The Powersupply, has HV caps, along with other goodies. Also contains several transistors, resistors, and the small heatsinks are good for putting on hot transistors or rectifier in an audio project.
Computer Monitors are even better. The circuit that plugs on the back of the CRT has HV transistors in sets of 3 for RGB and sometimes complementary pairs too. Also you will find a few good high wattage resistors and HV caps there too. My amp uses 150V transistors in the LTP and CCS taken from computer monitor. I also got a bunch of trimmer POTS from various monitors. You can never have enough trimmer pots.
Also lots 1/4W and 1/2W resistors in somewhat standard values can be found.
Lol you should not of said that...
Just completed stripping a PC PSU last night, to use the board as a support and the case, for a gainclone PSU.
Caps were a bit dissapointing, save for the 2 200V 470ufd ones... lots of little toroids and transformers I cannot yet identify, diodes, 2 small alu heatsinks that can mount to PCB with solder, number of large resistors, I assume 1 or 2 watt. 3 pin powersocket, like at the back of some kettles, and PCs (of course), 110 / 240V selector switch, 80mm fan.
BUT NOW!!!!!!!!!!!!!!!!
tuh duh.... tuh duh tuh duh tuh duh, TUH DUH (jaws theme)
I am going to strip a viewsonic monitor. Erm where will the caps be that can shock me, and how do I discharge them?
Just completed stripping a PC PSU last night, to use the board as a support and the case, for a gainclone PSU.
Caps were a bit dissapointing, save for the 2 200V 470ufd ones... lots of little toroids and transformers I cannot yet identify, diodes, 2 small alu heatsinks that can mount to PCB with solder, number of large resistors, I assume 1 or 2 watt. 3 pin powersocket, like at the back of some kettles, and PCs (of course), 110 / 240V selector switch, 80mm fan.
BUT NOW!!!!!!!!!!!!!!!!
tuh duh.... tuh duh tuh duh tuh duh, TUH DUH (jaws theme)
I am going to strip a viewsonic monitor. Erm where will the caps be that can shock me, and how do I discharge them?
you discharge them by putting one finger at each pole 
uhh, no seriously, put a resistor between the poles, and keep it there for about 10. secs that'l do it deppending on the value of the resistor.
btw, i have found psu heatsinks to be more than sufficient for low power gainclones, and the filmcaps are great for decoupling.
the hv caps could be good for tube stuff perhaps?
i have a shitload of boxes and crates filled to the brim with electronics, plus i work one day a week at a electronics service shop.
things come cheap theese days.
uhh, no seriously, put a resistor between the poles, and keep it there for about 10. secs that'l do it deppending on the value of the resistor.
btw, i have found psu heatsinks to be more than sufficient for low power gainclones, and the filmcaps are great for decoupling.
the hv caps could be good for tube stuff perhaps?
i have a shitload of boxes and crates filled to the brim with electronics, plus i work one day a week at a electronics service shop.
things come cheap theese days.
So far so good, got all the big caps off the monitor PCB, in fact its pretty empty by now, not many large electrolytics, but lots of those jobbies which looks like rectangles of hardened enamel paint... must say I now have a pretty decent number of small capacitors for getting along in the electronics hobby again...
Wonder if I can find any use for some of the stuff though like the large ICs and transistors on there... Did get some pushbuttons I can use with the DS1669 digital pot as soon as I find one...
Once again a number of small heatsinks, one is quite nice with a sort of clip that holds the chip in place in stead of a a screw...
Wonder if I can find any use for some of the stuff though like the large ICs and transistors on there... Did get some pushbuttons I can use with the DS1669 digital pot as soon as I find one...
Once again a number of small heatsinks, one is quite nice with a sort of clip that holds the chip in place in stead of a a screw...
MrDodo said:
Don't know about after a few months but the tube itself is a giant capacitor and will definitely hold a charge for a few days at least, and it is at about 22,000V!!! The point where the high tention lead plugs into the back is the danger zone......(or I guess at the other end if you disconnect/cut at the HT transformer).....
danger points arrowed
sorry best pic of a crt I could find!Tony.
Attachments
MrDodo said:
A few months is fairly safe, but echoing Wintermute, the voltage in the CRT is huge and will kill you so it plays to be cautious. A long bladed flatblade screw driver with an insulated handle, grounded (a clip-lead to the chassis -- with it plugged in and off), one hand behind your back, safety glasses and you slide the screw driver into the anode cap of the CRT.
Go out on the net and look for a picture tutorial.
The HiVoltage caps in a CRT are usually quite good for tube amps (if you have to use elcos).
dave
The power supply and monitor will have the most usefull stuff...
Motherboard is all low voltage caps and surface mount stuff, CDroms, PCI cards, etc. dont really have anything usefull on them (unless you are really good with desoldering smds).
The boards also seem to use higher temperature solder, which can be annoying.
Giving me a dead PSU or monitor is almost better than a working one, because theres no guilt when I take it apart
Motherboard is all low voltage caps and surface mount stuff, CDroms, PCI cards, etc. dont really have anything usefull on them (unless you are really good with desoldering smds).
The boards also seem to use higher temperature solder, which can be annoying.
Giving me a dead PSU or monitor is almost better than a working one, because theres no guilt when I take it apart
PSU's always have 220-330uF cap's. But they are rated 250V. We know that cap in PSU will give it's best when loaded around 80% of their nominal voltage. In GC for example, we need 63V cap's. Talking high end, PSU caps are here useless. But I am always using them. Why to trow away. There are also a number of other caps in PC PSU that can be reused. Power transistors too.
Network cards have pulse transformer. It can be used when modding CD player (dig. out). I haven't got any answers whether this is even a slight audiophile approach or not. Somehow I beleive it is not.
There are some heatsinks here and there. PSU, chipset on motherboard, VGA cards, etc. Aluminium is always usefull.
Many times I have used wires from PSU for connection between amp board and output transistors. Hard to solder, not cooper, nice colors.
Elcos at the motherboard are rated 6.3V. Good quality, but low voltage. Eventually usefull if you need them in PSU which drives something digital that works on 5V.
There are some voltage regulators at the mainboard. This can be used too.
But, if you have old MFM or RLL hards you can find power mosfets which can be used to build some of Nelson's fine things. Before I found that I have thrown away some 20-30 old 10MB disks.
DVD-ROMS may have transport which can be used to repair some today's cheap DVD players, because they use computers transports.
Fans can be used for cooling. I usually clean them with vacuum cleaner, oil them, and they are as good as new. Run them at half of their nominal voltage and they are even quieter.
Scanners and matric printers can be used if you want to build CNC machine. They do have step mottors and rails for X and Y axis.
Scanner case can be used for a PCB "enlighter" (sorry, can't find appropriate word). Throw everything out, put in some neon lamps and make your own PCBoards.
Network cards have pulse transformer. It can be used when modding CD player (dig. out). I haven't got any answers whether this is even a slight audiophile approach or not. Somehow I beleive it is not.
There are some heatsinks here and there. PSU, chipset on motherboard, VGA cards, etc. Aluminium is always usefull.
Many times I have used wires from PSU for connection between amp board and output transistors. Hard to solder, not cooper, nice colors.
Elcos at the motherboard are rated 6.3V. Good quality, but low voltage. Eventually usefull if you need them in PSU which drives something digital that works on 5V.
There are some voltage regulators at the mainboard. This can be used too.
But, if you have old MFM or RLL hards you can find power mosfets which can be used to build some of Nelson's fine things. Before I found that I have thrown away some 20-30 old 10MB disks.
DVD-ROMS may have transport which can be used to repair some today's cheap DVD players, because they use computers transports.
Fans can be used for cooling. I usually clean them with vacuum cleaner, oil them, and they are as good as new. Run them at half of their nominal voltage and they are even quieter.
Scanners and matric printers can be used if you want to build CNC machine. They do have step mottors and rails for X and Y axis.
Scanner case can be used for a PCB "enlighter" (sorry, can't find appropriate word). Throw everything out, put in some neon lamps and make your own PCBoards.
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