thats all i need to know 😀 btw i will work on a project in next few days and post updates here. also HAPPY NEW YEAR !!!
75 w tungsten bulb limiter is better than nothing. LED bulb is useless. Some people in UK use a one cup tea boiler appliance series the mains, but it has to be immersed in a cup of water.
You did test all the transistors with the diode scale already? Or are you unable to reach them because no DVM probes? The alligator clip lead used to connect the DVM negative to power supply ground or speaker ground looks like this: https://www.parts-express.com/Medium-Alligator-Clip-22-AWG-Test-Lead-Set-10-Pcs.-360-152
If you already have meter leads that have the 1 mm probes that are too short for an alligator clip to connect to, you can buy grabber meter leads like this: https://www.parts-express.com/Banana-to-Mini-Grabber-Test-Leads-39-390-328
or alligator clip meter lead like this: https://www.parts-express.com/Banana-To-Alligator-Test-Leads-390-125
Use an electronics supply in your country of course, like farnell, RS, digikey (slovakia), or mouser (slovakia). .
You did test all the transistors with the diode scale already? Or are you unable to reach them because no DVM probes? The alligator clip lead used to connect the DVM negative to power supply ground or speaker ground looks like this: https://www.parts-express.com/Medium-Alligator-Clip-22-AWG-Test-Lead-Set-10-Pcs.-360-152
If you already have meter leads that have the 1 mm probes that are too short for an alligator clip to connect to, you can buy grabber meter leads like this: https://www.parts-express.com/Banana-to-Mini-Grabber-Test-Leads-39-390-328
or alligator clip meter lead like this: https://www.parts-express.com/Banana-To-Alligator-Test-Leads-390-125
Use an electronics supply in your country of course, like farnell, RS, digikey (slovakia), or mouser (slovakia). .
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my probes are ok, i did not check transistors yet with tester i will do it tomorrow. btw i will make that limiter with bulb tomorrow also and post the updates 😀
i will draw transistors and will put all values that i will get from them so you can see it. thats best way. because i dont know if values that i get are good or bad but i remember that one of two leads from transistor is like 400 something and other one is a bit mroe that that thats all i measured before
Sigh ....
Okay, sg97, you have got to understand some of this before you can fix anything. I know you just want to "fix it", but just because it works does not mean it is working correctly. Right now people are doing the fixing by remote, but you are the one with the stuff in your hands. We do our best, but that isn't enough without some understanding on your part.
The Tea cup warmer is not nearly the same as a light bulb. Use a light bulb if you must. I hate light bulb testers and wish they were never thought of, they introduce too many variables, and they do not make things damage-proof. They buy you time and will stop a short from causing too much more damage most times. It's still up to you to detect and prevent fault conditions from causing more damage. I use a Variac (metered), and although I can't see you buying one, that is what you should be using. Others here have no excuse not to use the proper device, enough said.
As I have said many times. Get used to how your meter reacts to transistors. I hope you bought a good (new) NPN and PNP transistor to teach yourself this. If not, please do.
-Chris
Okay, sg97, you have got to understand some of this before you can fix anything. I know you just want to "fix it", but just because it works does not mean it is working correctly. Right now people are doing the fixing by remote, but you are the one with the stuff in your hands. We do our best, but that isn't enough without some understanding on your part.
The Tea cup warmer is not nearly the same as a light bulb. Use a light bulb if you must. I hate light bulb testers and wish they were never thought of, they introduce too many variables, and they do not make things damage-proof. They buy you time and will stop a short from causing too much more damage most times. It's still up to you to detect and prevent fault conditions from causing more damage. I use a Variac (metered), and although I can't see you buying one, that is what you should be using. Others here have no excuse not to use the proper device, enough said.
As I have said many times. Get used to how your meter reacts to transistors. I hope you bought a good (new) NPN and PNP transistor to teach yourself this. If not, please do.
-Chris
@ Chris
If you knew how much I salute your patience and your altruism.
If you knew how much I salute your patience and your altruism.
good idea but i will buy all new transistors so i can be sure its none of them and i will mess around with old ones
Yes, they are stamped, but you must have a good magnifier to even see them clearly. Sometimes it is white ink, but many times it is more like a branded part number.
Bend one of them back a little, and you will see it on the flat side.
Bend one of them back a little, and you will see it on the flat side.
i will remove transistors from board and check this if there are markings that would be cool xd
removal by newbies causes more damage than leaving them alone. You don't need markings to buy the small round ones. There is only one kind of mid sized EBC silicon transistor sold pnp & npn, usually at most sources zero. TO5 package as you have is extinct. I can sometimes find an EBC TO39 package in stock at farnell. If huggygood wants to give you anything, 2n5320/22 are what my ST120 had. Mooly provided some old European part numbers in post 14 & 19. 2n2907 as post 117 is wattage limited only suitable for the input transistor. Plastic pack transistors are BCE and require twisting the leads around to install for EBC parts. I damaged my circuit board doing that. Lifted the lands up ( which can happen any time you remove any part from a pcb).
If you want to test your meter, measure the diodes in the power supply between transformer and Capacitor. 500-700 forwards (black to line) 9999 or ----- backwards. If you meter does not read that, change the battery and if it is still not right, buy another from a major supply house. I like tenma thest days. 400 is not a legitimate silicon transistor reading. I have seen damaged trsnsistors read 450-470 BC.
If you want to test your meter, measure the diodes in the power supply between transformer and Capacitor. 500-700 forwards (black to line) 9999 or ----- backwards. If you meter does not read that, change the battery and if it is still not right, buy another from a major supply house. I like tenma thest days. 400 is not a legitimate silicon transistor reading. I have seen damaged trsnsistors read 450-470 BC.
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