Boo.... and my head sinks down to the table in despair!!! Not what I wanted to hear but sounds about right. I was going to hook up a couple of 12v batteries in series and try it on 24v but am clutching at straws at this point _ I did read somewhere (I can't find the post) about the boards locking out as some PS give an initial 53v at start up which locks the boards out but I don't think that's what is happening to mine. I appreciate the input from all. Was so close yet so far! £ days at work now to console myself and consider my options.
Sorry man! I know the feeling, especially when it comes to stuff that takes it's time from the east. About a year ago when I first discovered 5v DC-DC isolators and how they are a saviour to bluetooth/amp board set ups I ordered a single one from china. I unwrapped it like it was Christmas, immediately soldered to a 19v PSU and fried the thing. 4 weeks I waited for it. For some reason I didn't realise they were available locally (perhaps this is a double installment in how dim I can be sometimes).
This guy makes it look unreasonably easy: YouTube - You have nothing to lose but the few quid the chip and inductors that Jim suggests may be gone too. I have a found that in a situation like this (if it is fried) you have nothing to lose and only experience to gain even if you don't get it up and running again.
Good on Doug for helping out so much!
This guy makes it look unreasonably easy: YouTube - You have nothing to lose but the few quid the chip and inductors that Jim suggests may be gone too. I have a found that in a situation like this (if it is fried) you have nothing to lose and only experience to gain even if you don't get it up and running again.
Good on Doug for helping out so much!
If it is any consolation, 3e do seem to ship fast. A little over a week when I have bought via ebay. I see they have an Aliexpress outlet now too.
For the record, I have hot swapped speakers on my 3e 3255 but i did it as quick as possible without a signal.
For the record, I have hot swapped speakers on my 3e 3255 but i did it as quick as possible without a signal.
Ha ha, the vid makes it look way to easy but as you said nothing to lose. My amp board took 6 weeks as they were sold out when I first went to buy it!! At least my other half doesn't have to hear me talking about it all the time and spreading it over the dining room table!!
A week - wow that was quick. Not keen to spend again but it's that or nowt so may have to do it. Will try a lower voltage in a few days but think it will have to be a re-buy. Still there are worse things going on right now in life so can hardly moan.
I tend to question the quality of a $70 amplifier when the chip, which is usually the least expensive part, is listed at $15 on my supplier's catalog. That leaves about $55 for ancilliary circuitry, bulk capacitors and other parts that can be quite expensive on their own. That heat sink would probably cost about $30 alone.
This is one of the problems with these boards... you never know if you are getting proper design, counterfeit parts, recovered parts or proper assembly. And from what I can discover EBay and Ali Babba are up to their eyebrows in it by not policing their sellers.
Looking more closely at the chip's specs...
I see that the clip and fault pins can only source 9 ma of current and the Reset can only sink about 9ma. Also these pins can only take -0.3 to 4.9 volts each. So one needs to be very careful when manipulating them... it's possible the reset has been damaged (by accidentally feeding it +12 volts, for example) and that's the end of that song.
It is also interesting to note that TI recommends holding Reset low for a time during power up to protect the outputs. Unless it is correctly implemented on that board it would require external logic so powering up with our little switch in the "On" position could be risky.
The thing with electronics like this is that once properly implemented and perminently connected these devices can be very robust and last a good long time ... but... they are very unforgiving of abuses, either accidental or otherwise.
My best recommendation for the future...
Decide on your board. Study it's specs and facilities carefully. Design your interface... case, on-off, reset, volume, etc... hook it up once, do any troubleshooting, and when it works, you're done.
Decide on your board. Study it's specs and facilities carefully. Design your interface... case, on-off, reset, volume, etc... hook it up once, do any troubleshooting, and when it works, you're done.
Thanks Doug and others for your help and advice. Will probably order another board and maybe in a few weeks time post a pic of a working amp. Thanks again.
No worries ... always happy to help.
But this time, don't play with it until you break it. 😀
Thanks. I made it - lots of time during lockdown - got a 'steel wall box', rubbed the paint off parts of it, left it outside for a few days in the rain (kept spraying it with salt/vinegar.hydrogen peroxide mix to speed it up), the meters and switch from fleabay, lights off a 1940s hotrod, sanded down chicken head knob to take the shine off, volume dial is metal, sanded to fade it and a couple of printed stickers and away I went. Certainly grabs peoples attention when they walk in and see it!!!
Thanks guys, haven't stopped listening to it since I did it - was a lot of fun to make and I learnt a lot ion the way - might add radiation icon tomorrow just to make my life complete