I got a few versions, just in case, may need them again and spares are always welcome.
Digikey:
BC 546 CTA CT-ND
BC 640 TACT-ND
BD 139 gos-ND 80V 1.5 amp To 126
BD 140 165-ND 80V 1.5 amp TO 126
MFR-25 FRE 52-100CT-ND (100 ohm)
CMF5543R200 FHEB 43.2 1/2 watt. May be too big?
Got some 1/4 watt ones coming from Mouser just in case. Hopefully 43.2 is close enough!
Digikey:
BC 546 CTA CT-ND
BC 640 TACT-ND
BD 139 gos-ND 80V 1.5 amp To 126
BD 140 165-ND 80V 1.5 amp TO 126
MFR-25 FRE 52-100CT-ND (100 ohm)
CMF5543R200 FHEB 43.2 1/2 watt. May be too big?
Got some 1/4 watt ones coming from Mouser just in case. Hopefully 43.2 is close enough!
all good
again, resistors are 0207 size of the body; you can't and do not try to squeeze bigger, pad vias are in danger if trying to bodge thicker pin in
again, resistors are 0207 size of the body; you can't and do not try to squeeze bigger, pad vias are in danger if trying to bodge thicker pin in
Looking at Mouser, I don't see this sizing info. Speaking of 0207 you mention. I was afraid the 1/2 watt may be too large. I do have some coming from Mouser in 1/4 watt.
One board out, carefully wicked away solder from pins mounting 10 gauge wire to power supply, and removed them from board. Once detached from mosfets, board is quite maneuverable with only flexible signal wire still attached.
Three smoked resistors out and pads cleaned up. Also cleaned up pads for U+,U- and ground on PC board.
Next will remove the "transistor sandwich" and test those parts. If by strange chance they are good I will be surprised, they look normal enough, but does not mean they are good. If good, I will decide whether to remove and test other small active devices or try just resistors? Pretty sure I remember LEDs on when I first turned off after smoke poof.
Russellc
Three smoked resistors out and pads cleaned up. Also cleaned up pads for U+,U- and ground on PC board.
Next will remove the "transistor sandwich" and test those parts. If by strange chance they are good I will be surprised, they look normal enough, but does not mean they are good. If good, I will decide whether to remove and test other small active devices or try just resistors? Pretty sure I remember LEDs on when I first turned off after smoke poof.
Russellc
Attachments
as Dr. Haus is saying - Everybody lies
so, I don't believe even my self, let alone in own eyes .......... sole thing I believe in is DMM
Hi
Protection for loudspeakers is not necessary ???I didn't see them in any post….
Zen mod- I was writing you a message
Have nice day
Protection for loudspeakers is not necessary ???I didn't see them in any post….
Zen mod- I was writing you a message
Have nice day
it is, with any amp, if you like your speakers, with exception of amps having coupling cap at output
I'll reply to piled PMs hopefully this night
@Russellc Having been through this exercise a couple of times ... replace more parts not less. Even if a part tests good today, it may have suffered during the puff and give up the spirit tomorrow. Also, from my recent amp adventures, 'if it ain't broke, don't fix it' - leave the healthy channel alone. I did just what you described and monkeyed up a good channel. Now I have a few miss-matched parts between the boards, so what, they sound better than ever.
I suspect they are toast. I was only referring to fact they are not burnt, smoke blacked or melted.
Did make a scary pop...
I'm pretty sure I slow motioned, turning somersault in air like kung fu movie hitting switch and pulled plug so fast I experienced a touch of red shift, altering the time space continuum. Likely saving nothing but cats were impressed 😁
Zenmod, post #1936 you suggest to member cwlo to replace R18, R19, T6, led1, R21, R22, Q1, Q2 and R24.
Would you suggest same parts with my mishap? Problems caused by 2 different circumstances, other amp was missing a resistor, whereas mine got a nasty transient.
I also ordered the other T items as well. I did not order the led, will have to get those. I see it must measure correctly, 1.9 volts, is there a particular led part, or just get a bunch and measure?
Thanks,
Russellc
Would you suggest same parts with my mishap? Problems caused by 2 different circumstances, other amp was missing a resistor, whereas mine got a nasty transient.
I also ordered the other T items as well. I did not order the led, will have to get those. I see it must measure correctly, 1.9 volts, is there a particular led part, or just get a bunch and measure?
Thanks,
Russellc
pretty much - same vertical of parts involved in mishap
precision of said voltage isn't so critical - it can be green or red, so ref. voltage in range of 1V8 to 1V9; LED type is - plain normal diffuse one - those are of older/usual variety, not modern superbright ones
I bet you have some in drawer already
I have blue. Short of install, fire up and measure voltage across led, I assume no other way to make this measurement of 1.9 V? I know how to test with multimeter as to leed orientation,not voltage across it. Is T6 the only one of T1-T7 that should be replaced, I did order them all.
Blue all I have on hand. I ordered a selection of what Mouser calls "standard led" in green.
On the resistor front, ones coming are "3 mm" is only size info I found so far, but selection of them coming, surely one will fit.
On the resistor front, ones coming are "3 mm" is only size info I found so far, but selection of them coming, surely one will fit.
Most of parts came, guessed well with resistors they are all as small as originals. Transistors with plenty of spares in case I do something silly again.
Looked at transistor tester device, will be first use. IIRC this was a 6l6 recommendation and I ordered one. Will have to peek on interwebs to see how it works.
Looked at transistor tester device, will be first use. IIRC this was a 6l6 recommendation and I ordered one. Will have to peek on interwebs to see how it works.