Author Topic: How do I test a LM3886TF power amp chip?  (Read 5072 times)

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Offline LektroiDTopic starter

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How do I test a LM3886TF power amp chip?
« on: September 29, 2014, 11:51:52 am »
I have a faulty Tannoy Precision 8D speaker, I've replaced the regulators & rectifier (I had these in stock so I thought I'd replace the parts I had before spending money). It's looking like it could be one of the power amplifiers that have failed. So, I bought some from evilBay, but they all have different manufacture codes. They look unised, but I would like to test them before soldering them in, as they are real bastards to remove.

Any ideas how I could test them before commiting them to the PCB?
 

Offline diyaudio

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Re: How do I test a LM3886TF power amp chip?
« Reply #1 on: September 29, 2014, 01:02:48 pm »
I have a faulty Tannoy Precision 8D speaker, I've replaced the regulators & rectifier (I had these in stock so I thought I'd replace the parts I had before spending money). It's looking like it could be one of the power amplifiers that have failed. So, I bought some from evilBay, but they all have different manufacture codes. They look unised, but I would like to test them before soldering them in, as they are real bastards to remove.

Any ideas how I could test them before commiting them to the PCB?

yes, if you really paranoid just build a bread board test jig it requires some effort from your side, if you lazy,  remove the old one, and just resolder the new one, set-up with a cheap speaker to verify its operational.
 

Offline macboy

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Re: How do I test a LM3886TF power amp chip?
« Reply #2 on: September 29, 2014, 01:03:40 pm »
LM3886 is commonly suspect of being counterfeit. Best bet is to buy them from big distributors (Digi-key, Mouser, etc.) or direct from TI. If you want to talk to people very experienced in such things, head over to the chipamp forum at diyaudio.com .
 

Offline LektroiDTopic starter

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Re: How do I test a LM3886TF power amp chip?
« Reply #3 on: September 29, 2014, 02:49:41 pm »
LM3886 is commonly suspect of being counterfeit. Best bet is to buy them from big distributors (Digi-key, Mouser, etc.) or direct from TI. If you want to talk to people very experienced in such things, head over to the chipamp forum at diyaudio.com .

Counterfeit meaning they do not work, or made by a unregulated manufacturer?
 

Offline SeanB

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Re: How do I test a LM3886TF power amp chip?
« Reply #4 on: September 29, 2014, 05:08:01 pm »
Both, or they may be so poorly made that they work at low power, but fail ( often in a spectacular way) when you start to turn up the volume.
 

Offline dundee

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Re: How do I test a LM3886TF power amp chip?
« Reply #5 on: September 29, 2014, 10:16:43 pm »
 


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