I have a ST4151V chip I'd like to know how to go about testing it for shorted outputs.
I have the datasheet but not sure I quite get it.
Thanks, nosaj
From the data sheet, pins 10 and 13 are the outputs, so measure them to either power pin. This is just a transistor circuit in a box, so test it as if it were individual parts. You just can't get at all the parts. I often do that in large amps. I measure resistance from the red output terminal to the main filter cap hot leads.
I get about 3megaohms one way and OL with the leads reversed for both outputs. So I'd say it's not shorted.
Nosaj
Probably not shorted, but remember you are only testing its output transistors.
And you noted that the V= was common, but the V- had separate terminals, one per channel.
What is the actual symptom?Doesnthe amp blow fuses?
Do you have DC on the speaker out?
As noted by Enzo, these are "conventional amps in a box", intended to ease assembly to manufaturers and simplify servicing by full replacement, obviously they are not meant to be opened and replaced, in fact I guess you want to confirm whether ordering a new one or not, but I know for sure that in certain Countries, notably in Central America (and maybe Cuba?) , there´s Techs who cut the plastic case open, somehow unsolder original transistors and solder new ones to the backplane.
Guess that can be done with TO220 cases, maybe larger ones.
At first the yamaha piano wouldn't turn on But after resoldering the chip back in I was greeted with piano noise. When i would play it loud it would cut out and sometimes reboot.
After lifting the other circuit board I found the metal dimpled upwards making slight contact with the circuit board. After hammering it down and reinstalling everything. It doesn't cut out or reboot anymore.
Someone had put a bolt in that was too long and it bent the metal towards the board.
Thanks,
nosaj