Posts by kate@mk.absturztau.be
(DIR) Post #B6JQORIXV203d9B2ae by kate@mk.absturztau.be
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@puniko ...der muss mit Absicht gekommen sein, denn sonst würde sich ja keiner von der Blase ins Fediverse verirren?
(DIR) Post #B6JXNDTG7dgC8UYTVw by kate@mk.absturztau.be
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@puniko ...irgendwie ist es auf Bluesky seltsam... da fühle ich so ungute Vibes seit einer Weile, aber das hat nix mit den Idioten zu tun ....
(DIR) Post #B6Ja1fSlfRZURYk3JA by kate@mk.absturztau.be
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@puniko ...da ist es kühl wie auf einer Seite einer Zeitung, so ... weiss nicht, berichterstatterisch? und wenig persönlich? vermutlich aber nur die Blase die ich sehe.... bin da kaum aktiv....
(DIR) Post #B6a4ctNuyXQLUQUx7o by kate@mk.absturztau.be
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@puniko .... lucky you. :patawoozy:
(DIR) Post #B6aBHlmojLDzWP1HpQ by kate@mk.absturztau.be
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@puniko .. during this week I woke up each morning with a high frequency humming in my ears. Tinnitus. That sound is similar to what you hear when your dentist will drill a hole in a tooth. :blabfoxaww:
(DIR) Post #B6aBJmwNPU8zgFSBaC by kate@mk.absturztau.be
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@puniko ...meow!
(DIR) Post #B6kVKRZyjgW9kKuuCu by kate@mk.absturztau.be
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@niconiconi ... do manufacturers actually still have fuses inside amplifiers for speaker protection? I thought that to be a short lived fashion after all?
(DIR) Post #B6kWp261dCl9dw3Y4O by kate@mk.absturztau.be
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@niconiconi .... in all earnest? the HiFi bubble is getting weirder. I just found a "gold standard" fuse on offer for a substantial amount of money to replace any lingering fuses inside your sound system.Mind your head: it is also available for replacing the fuse in your outlet or fuse switchboard. :ablobfoxhyperowo:Funny that that "fuse" syndrome also affects tube amp hifi systems. In case a tube is going to suffer from a spike that fuse cuts off grid voltage, so your poor tube definitely is burning up bright and short. Currently investigating a cheap valve amp here ... :blabfoxaww:
(DIR) Post #B7KAFSid07Ywi96niq by kate@mk.absturztau.be
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@niconiconi ..at least in case you connect the heater ...
(DIR) Post #B7KAFSugHJChJWkQVc by kate@mk.absturztau.be
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@niconiconi ... I'm currently building a tube amp ;-) :ablobcat_cordkamikami:
(DIR) Post #B7QUsP6pWFzWqE2DWy by kate@mk.absturztau.be
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@puniko ... digitally I hope? :ablobfoxhyperowo:
(DIR) Post #B7SX09miUIxdntolwu by kate@mk.absturztau.be
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@Stellar ..that looks like a switching power supply? Those often follow weird schematics and make use of very rare components and rare silicone...
(DIR) Post #B7SZbjNbJFOIp37AeG by kate@mk.absturztau.be
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@Stellar .. in wich case you should check all other components. I assume you haven't got any schematics of this?Those switching power supplies often do have protective fuses in the input section close to where the power cord is attached. Some do have over current and over voltage protection. Some of these are "one way" components. They usually connect between the live wire and protective earth/ground. So they could be permanently shorting the input after having saved your electronics once against overcurrent or overvoltage. They often look like blue insulated discs with two wires. Some are also orange or black, but blue is most likely. When you post a photo with better resolution I probably can come up with more hints if you like?
(DIR) Post #B7Sj2vguXiy0PbBtx2 by kate@mk.absturztau.be
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@Stellar ... they all should have a resistance of megaohms. But, this isn't always easily measured with a battery powered meter as the probing voltage might by 9 volts max. They still might break down when 120/230 Volts get attached.Also there usually is a bridge rectifier somewhere that creates DC from the input voltage first before that is switched down by various switching units. Since you checked all capacitors the rectifier might have a single diode or more shorted. Which can blow your fuses anytime too. When you like just shoot a photo more close up of all the PCBs and I have a look what you can check. When you feel it is not for the public feel free to post it in a private message to me.
(DIR) Post #B7Sno1bWm7p8B7NwgK by kate@mk.absturztau.be
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@Stellar Great! .. so ... all your blue disc items are capacitors, so far so good. The PCB has descriptive names of components on it, which is great.The is one component close to the input terminals that looks like a black disc and is makred on the PCB as VDR ... Check any and all components that bear that name VDR. VDR is short for Voltage Dependent Resistor. Those react to overvoltage and should afterwards self-rest to a high resistance again. Your meter should show many Megaohms.Also a bit further there is the bridge rectifier in a black plastic casing that is characterized by a cut off edge. In case you can identify the brand and name of the rectifier you could find the layout of the connectors. If not you can try this: usually the two middle wires of the four in a row are for the AC and the two at the end of the connector row are the DC connectors. Just check all 4 connectors for a short with your meter.All the bigger capacitors look like in good shape. A faulty capacitor is easily found by checking the metallic bare top of the capacitor where there are some fine lines in the metal. These lines are the intended cracks in case the capacitor has overloaded and would blast off. There are no dark spots or visible coal like burnings anywhere as far as I can see. So that is a good sign.Now for the sinister things. Just in case all the above checks do find nothing the culprit might be an overloaded transistor in the switching sections. Also there are several diodes visible. All those are very hard if not impossible to check in-circuit. What you can do however is check their terminals from the soldering side for any shorts. However, since the switching sections connect the transistor switches to chokes and transformers with very low resistance, so a low meter value doesn't tell you if it is a short or not in all cases.Make sure your values are really zero to conclude it is a short inside the diode or transistor.Proceed to all your PCBs in that way to find any clues or faulty components.Get back to me with any or all findings and photos of the other PCBs if you want.Also feel free to send me messages to my e-mal if you want.Also yet another hint: if possible check all transistor switches for their ID, name and brand. That might help a lot later on to find replacements and the layout of thier respective connecting wires. Good luck!!
(DIR) Post #B7Swz5tW429yFz9V5c by kate@mk.absturztau.be
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@Stellar ..those blue capacitors have a low capacitance, so their loaded even by the small voltage of your multitool quite quickly so you do not see them loading.
(DIR) Post #B7SxTWlciU4KHwyLGi by kate@mk.absturztau.be
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@Stellar the fast-blow glas fuses of that type should generally be available in stores that sell electronics and fuses. Amazon has them too.When the fuse blows it means that the current rushing through is far too high, hence there is a fault or short behind it.
(DIR) Post #B7SyEFHJYcAfes4XjM by kate@mk.absturztau.be
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@Stellar Yes the T means slow and F means Fast. 5A means that the fuse blows at 5 amps or more. So that PCB is protected by it and the fuse avoids the PCB to burn and hence avoids fire. T5AH are quite common, also higher currents are available. Those glasses fuses are also available up to 10 A. The higher value fuses are filled with sand which you easily can see in case you have one of these. Do not attempt to replace this fuse with one of higher current value! This only increases the risk for more damage.
(DIR) Post #B7Sz6ycZBqERvL6vQG by kate@mk.absturztau.be
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@Stellar be careful when you get a set of these. My experience with sets is that they sometimes mark the fuses with cryptic text and not the standard terms for the rating.The rating should be carved on the metal ends. sometimes it is also printed on the glas. And in cheap-o boxes the have none. You must be careful to read the little inscriptions on tiny paper stickers in the box. Beware!
(DIR) Post #B7T0TXWqBVx0VrksuO by kate@mk.absturztau.be
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@Stellar ..that is insane! Those boxes must have hundreds of fuses in them? IN any case I guess that is total overkill?Cannot you just purchase twenty of those you need?