Very first post at diy...
Hello,
Can anyone make a stab-in-the-dark diagnosis (or general area I should look into) from this description? Much appreciated!
I own a Job 225 amplifier which emits loud "pops" (through speaker) on the right channel upon start-up. It throws up a variety of "wheezes," buzzes and pops, all intermittently, within the first 5 - 20 minutes of start up. And then all of a sudden it's all quiet and fine again, till next start up...
Apart from this the amp functions normally. From the loudness of the pops, I would surmise the signal is no more than a watt in level (to the speaker). The issue started after couple years of normal usage, and it has progressively gotten worse. I can say the issue is strictly with the amp itself and not with any other components.
Has anyone had similar issue with their amplifier (any brand)? Thanks for looking...
Hello,
Can anyone make a stab-in-the-dark diagnosis (or general area I should look into) from this description? Much appreciated!
I own a Job 225 amplifier which emits loud "pops" (through speaker) on the right channel upon start-up. It throws up a variety of "wheezes," buzzes and pops, all intermittently, within the first 5 - 20 minutes of start up. And then all of a sudden it's all quiet and fine again, till next start up...
Apart from this the amp functions normally. From the loudness of the pops, I would surmise the signal is no more than a watt in level (to the speaker). The issue started after couple years of normal usage, and it has progressively gotten worse. I can say the issue is strictly with the amp itself and not with any other components.
Has anyone had similar issue with their amplifier (any brand)? Thanks for looking...
Looks like bad solder joints developed with time.
Check/reflow the board, connectors, wires...
Check/reflow the board, connectors, wires...
Yes. Many times.
I just beat it until it gets better. Or worse.
Agree with juma that this is usually loose contact "somewhere".
I've had one of those too. Turns out not soldering all the components leads to some really bizarre behaviour that is rather hard to diagnose.
Regarding OP: A bad solder joint will do what you describe. You might be able to provoke it by letting the amp warm up and then pushing on the PCB with the (insulated) handle of a small screwdriver or similar insulated poking device.
Tom
I now power up my pcb and twist it and any bad joints either pop through the speaker or cause the amp to output DC. I have an amp dc protector so that kicks in if a problem occurs.
I must revisit this, unfortunately... (Please see the first post for the original issue.)
Despite my best efforts, I have not been able to address any possible bad solder joints... (I have touched up various points.) So I've been basically just living with it as is, only connecting the right speaker after 15 minutes of startup.
Yesterday, when I connected the banana plug (right channel) into the amp, I saw a little light inside the terminal, with the resulting loud POP. I quickly removed it, but it did the same moments later when I attempted to connect it again. After that, it was all good again... back to normal operation.
I'm not an electronics engineer, but I'm guessing it's a grounding issue of some sort (?). I would appreciate any stab-in-the-dark suggestions/prognosis. Could it still be a bad solder joint?
Thanks once again for your help.
Despite my best efforts, I have not been able to address any possible bad solder joints... (I have touched up various points.) So I've been basically just living with it as is, only connecting the right speaker after 15 minutes of startup.
Yesterday, when I connected the banana plug (right channel) into the amp, I saw a little light inside the terminal, with the resulting loud POP. I quickly removed it, but it did the same moments later when I attempted to connect it again. After that, it was all good again... back to normal operation.
I'm not an electronics engineer, but I'm guessing it's a grounding issue of some sort (?). I would appreciate any stab-in-the-dark suggestions/prognosis. Could it still be a bad solder joint?
Thanks once again for your help.
It is a bad connection. "Somewhere". These can be hard to find.
Switch contacts. Jack contacts. The ever-popular solder joint that looks good but is "only touching", not BONDED. IC sockets. (I "fixed" many Apple ][s by leaning on all the socketed chips until they "creaked".) Less common troubles are the factory terminations on resistors, capacitors, and rarely semiconductors.
Switch contacts. Jack contacts. The ever-popular solder joint that looks good but is "only touching", not BONDED. IC sockets. (I "fixed" many Apple ][s by leaning on all the socketed chips until they "creaked".) Less common troubles are the factory terminations on resistors, capacitors, and rarely semiconductors.
Recommendation Sought for a Repair Shop in NYC...
Hello,
(I don't believe this is an offense as per the rules, but please delete if it's so.)
I'm looking for a reputable electronics repair shop in NYC to fix my JOB 225 amp. I have just accepted that the problem at hand (the "pops," the arcing, etc.) is just beyond my ability...If anyone can recommend a solid place, I would be much grateful.
Thanks in advance.
Hello,
(I don't believe this is an offense as per the rules, but please delete if it's so.)
I'm looking for a reputable electronics repair shop in NYC to fix my JOB 225 amp. I have just accepted that the problem at hand (the "pops," the arcing, etc.) is just beyond my ability...If anyone can recommend a solid place, I would be much grateful.
Thanks in advance.
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