K8060 Power Amp R16 (47) blew when 1st powered on - the fuse didn’t blow (1amp slow blow)
I followed all the instructions and the 60w bulb didn’t light up at all - never got arounf to trimming!
I’ve checked but can find no errors in the assembly - where can I start to fix it, without starting from scratch?
Any advise would be very welcome - thanks in advance… Jeff
Not only you have problems like that.
The first time I build this amplfire it happend me also.
What i did was just desolder the thik solderpoints and cleaned the PCB.
Then i resoldered the parts again with a small solderpoint and yes it was ok.
First I had to replace the TIP’s ofcourse.
Yes it’s a small PCB and I think there was a point that connected an other point what was not so ment.
Otherway : The best you can try from scretch.
hi had the amp working fine for a while using it as a sub amp in my car inverter on a 2x30v120va thingy from R.S.,felt it could do with more power so i [color=#FF4080]replaced the big caps with 4700uf50v as on page 7[/color],which made the maplin 3oow inverter beep alot cos it couldnt provide enougth power,doh.
i sat it aside a while until this evening ,on plugging it in it made a whizzing noise([color=#FF4080]no speaker attached oops[/color]) and i could see i[color=#FFFF00] bright light coming through the gaps[/color] in the enclosure the sound turned into a crackling sound needless to say it was turned off sharpish,amongst the soot on the board and a cheeky replugin to see whats frying i assertain that resistor 16 has decided to turn into a rudimentary light bulb??
shall i just replace the resistor or did something else cause this?
should i consider putting in the blue type resisters
( i have not got the tip147and the other one in the wrong place 
)
[color=#80BFBF][color=#FFFFFF]am planning to connect the amp to a 555squair wave generator and a 1200w longstroke sub ,as an aid to finding and securing items causing cabin rattle in car[/color][/color]tried to add image erm lets av another go ps amplifire lol,.facebook.com/photo.php?pid=2 … 0396760258
Check if R19 is still OK.
Most likely, the upper power transistor is defective.
thanks for the reply,the plot thickens
R20 (47 OHM )tested at 1to 0.9 ohm, no continuity through R19(disconnected one end of each to stop other components affecting the reading),replaced R16 as i was in the area ,earlier failure had caused track pad to lift a bit but still have continuity,
by the top transistor i guess you mean T8 TIP 124, where do i investigate next?
I mean the TIP142.
Hard to tell what else could be defective, without being able to examine your circuit.
Safest, fastest and easiest solution is to simply replace all semiconductors.
Is that code for BUY ANOTHER ONE ?
as ironically this seems to be the most economical option at… £15 .
Because buying components is not cheap unless buying 100s of the things,
and this board does require some specific bits.
:–Slow blow fuse(not included) at… £? .
:------Heatsink to stop it frying lol(not included)…£10 .
:---------As it is i got a bag of spair capacitors (4700uf as in diagram but not in kit)…£6-£10 .
:------------The transformer to power the amp(not included)…£20-£30 .
:---------------Power switch (not included)…£3-£7 .
:------------------Mains plug and cable(not included)… £extra .
:---------------------speaker wire(not included) …£extra .
:------------------------signal input socket(not included)… £extra .
So far this super budget amplifyer option has a total cost of between… £54-£72 .
Additional tips would be £2-£3 each and R19+20 around £1-£2 each these prices are non inclusive of postage apx£5.
Considering that the board has nearly blasted its tracks off not sure that a total overhall of the board is a sound investment.
Not sure about putting the assembely in post(with or without transformer and cabinet?) havent looked into the costs here.
As for my soldering i have enougth confidence in it as i have had experience and sucess with other items,white goods,games consoles,lots of diy kits,waterproof items,kinetic sculpture,
besides the amp worked fine not too long ago.