Discussion in 'Pioneer Audio' started by joe4fun, Jul 5, 2011.
So My next question is do I need a heat sink??
Is the transistor getting very hot?
I have not changed it yet because I did not know whether I need a heat sink or not
If your replacing a smaller case size transistor to a larger case style then a heat sink may not be needed. If you are unsure, carefully run it and keep very close eye on temperature and make a judgement.
Thanks QSilver will give that a go
OK ... first off - thank you all for the replies - the popping and cracking was only present in PHONO - FM and AUX work well - I hardly ever use the FM and AUX only use this for playing records - last week a pop and crackle and lost my LEFT channel - from reading posts on here I replaced all the transistors on the AWF 011 bd - same situation - No Left Channel - looking at the schematic the -19V is -48V ??? Has anyone ever seen this?? I followed the signal that back to the Power Supply Bd.- please see the attached file ... any help would be greatly appreciated - please note I know just enough to get myself in trouble -
The EQ issues probably took it out.
You should replace the EQ transistors again.
And recap it.
C1 and 2. 80-MMK5104M50J01TR18
C7 and C8, 647-UPW1A331MPD1TD
C11 and C12, 647-UKL1H3R3MDDANA
Thank you very much for the input ...I ordered the transistors for the PS board and should have them Monday or Tuesday. If that does not do the trick will reorder the transistors and caps - again, thanks for the help / suggestion ...have a great day !!!
Hi all, what would be a suitable replacement for the 2SB536
I would call Mouser ... their Tech Support is not only very knowledgeable, but very helpful.
It would help if you detailed the model number (SX-850?), board number(AWH-059) and part number (Q11?Q12?) because there is never a simple answer.
If the above assumptions are correct, you need 512-KSA940TU for q11,q12 and 512-KSC2073TU for Q9,Q10.
Sometimes the factory part used and a replacement will not directly correspond.
When the phono amp tanks, if it's the power supply, it will kill BOTH channels, not one.
Once new caps and transistors are installed, you should really do the FIRST thing and verify that the phono jacks
in the back are actually connected to the phono inputs and the signal is making it through the switches AND
in the case of PHONO 2 also the left and rightr channels are making it through the MIC jack!!
Use the ohmmeter function of the DMM from the center contact of each of the 4 phono plugs, to pins 19 & 20 of the AWF-011 board. It should show 100 ohms on the switched-to input.
Be aware that an unused (NOT switched to) phono input is connected to ground through each jack's 100 ohm resistor series resistor. Check the resistors as well, in case some schmuck blew them up.
phono 1 left R2
phono 1 right R1
phono 2 left R3
phono 2 right R4
BTW Juicer and especially pjf610 - both should have started their own threads....
Very sorry ... I was unaware - I made a comment a while back on this thread thanking everyone for their input when I first got my Pioneer - the info was very helpful - then - BANG - stuff hit the fan - please except my apologies
I replaced Q6 and the -48V is now -19V and I have left channel in phono ... many thanks for the input !
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