i pulled the pot and it was 90ohms across. i put it back and still no love.
the measurement between the D pins is 150 ohms
mdr
😡
the measurement between the D pins is 150 ohms
mdr
😡
Reads 150 ohms due to the capacitor in parallel , 90 ohms is close enough.Id say pot is probably OK
sorry I had the p pins confused.
There is .07mv across the p pins and nothing across the N pins.
I replaced the 10uf cap, just in case, but still nothing.
I pulled the pot again to test the wiper and it seems fine.
😡
I'm really appreciative of all your help.
thanks\mdr
There is .07mv across the p pins and nothing across the N pins.
I replaced the 10uf cap, just in case, but still nothing.
I pulled the pot again to test the wiper and it seems fine.
😡
I'm really appreciative of all your help.
thanks\mdr
Bummer!!! If you have your +/-45vdc on pin C of the output pair then I'd be looking for a new pair🙁 Check and see if you can adjust the good channel up and down a little then return it to the original setting.
Yes I'm able to adjust the good channel (Right channel).
"If you have your +/-45vdc on pin C of the output pair then I'd be looking for a new pair"
are you talking about the regulators on the PS?
cause I'm getting aprox 30v on the outputs of them.
thanks again
mdr
"If you have your +/-45vdc on pin C of the output pair then I'd be looking for a new pair"
are you talking about the regulators on the PS?
cause I'm getting aprox 30v on the outputs of them.
thanks again
mdr
No,not the PS regulators their workin' just fine.I was refering to the SAP 15 pair in the non-working channel. SAP 15-N may have a open emitter resistor(internal resistor).
Would that prevent me from seeing voltage across the S & E pins?
Should I swap it out with the other N from the Right channel?
thanks
mdr
Should I swap it out with the other N from the Right channel?
thanks
mdr
I'd leave the working channel alone.
yep.I don't have any idea the cost of a new pair.But if one took another hit chances are the other had some damage also.If you can swing it.
Only problem now is SAP15 and 16 have been discontinued by Sanken!
They have a replacement, the STD03, but these do not have built in emitter resistors. I think this is due to the fact that the on-chip resistors failed too easily.
You could retrofit these devices into a design using SAP parts, but you would have to add the missing resistor - typicaly 0.22R 3W devices.
You'd have to solder one end of the resistor to the Emitter pin, insert the other end into the hole where the emitter of the SAP transistor would go, and then connect the junction between emitter and resistor to where the Sense pin would have been.
It might be worth contacting Cambridge Audio and asking about obtaining output transistors from them - they may well have plenty of stock. Expect to pay a markup fee, though.
They have a replacement, the STD03, but these do not have built in emitter resistors. I think this is due to the fact that the on-chip resistors failed too easily.
You could retrofit these devices into a design using SAP parts, but you would have to add the missing resistor - typicaly 0.22R 3W devices.
You'd have to solder one end of the resistor to the Emitter pin, insert the other end into the hole where the emitter of the SAP transistor would go, and then connect the junction between emitter and resistor to where the Sense pin would have been.
It might be worth contacting Cambridge Audio and asking about obtaining output transistors from them - they may well have plenty of stock. Expect to pay a markup fee, though.
I checked the resistance between the S&E pins and it registers .4 on my Radioshack meter.
same for both channels.
AAAARRRRRGGGGGHHHH!!!!!
my next step is to de-solder parts from the working channel and swap them with the non working channel till I find the culprit.
I'm getting really good a de-soldering
😀 😉
same for both channels.
AAAARRRRRGGGGGHHHH!!!!!
my next step is to de-solder parts from the working channel and swap them with the non working channel till I find the culprit.
I'm getting really good a de-soldering
😀 😉
Does D211 LED light up on the non-working channel pc board ? Before cannabalizing the good channel can you may a printout of the amplifier boards both right and left , then measure the voltages around each transistors emitter,base & collector - write them legibly for both the good and the bad channel. Both channels are identical so voltages should be real close any voltage that is more than 2 or 3 volts off should be a clue and will aid in tracking down and localizing the problem.
The only other possibility is a bad component on the power amps driver or pre-driver ie Q214 & Q219 for starters.
Well,
One side of the power supply started to blow fuses(FU202), and I noticed a little residue around the base of the Caps. So off they came. And here is the result.
Any suggestions for removing the gunk?
Needless to say I will be replacing these with new caps, Any suggestions on better ones?
I will also replace the regulators and diodes any suggestions on make?
Ok I'm replacing the whole PS.
thanks
this is beginning to take on a life of it's own.
mdr
One side of the power supply started to blow fuses(FU202), and I noticed a little residue around the base of the Caps. So off they came. And here is the result.
An externally hosted image should be here but it was not working when we last tested it.
Any suggestions for removing the gunk?
Needless to say I will be replacing these with new caps, Any suggestions on better ones?
I will also replace the regulators and diodes any suggestions on make?
Ok I'm replacing the whole PS.
thanks
this is beginning to take on a life of it's own.
mdr
That residue doesnt look like residue, and looks more like glue used to hold the capacitors in place.
Well ,you have either shorted out one or more of the diodes in the fullwave bridge rectifier or you have a shorted SAP15 or have a bit of solder causing the short.That stuff from the caps can be chipped away with a exacto knife(usually dried up glue (sony bond).😉
Thanks for your replies.
Since I'll be replacing the Diodes anyway any particular brand style, schottkys?
As far as the Caps go any favorites?
thanks
mdr
Since I'll be replacing the Diodes anyway any particular brand style, schottkys?
As far as the Caps go any favorites?
thanks
mdr
Best just to get machine working 100% before any tweeking.I usually get nichicon or united chemicon or whatever is available.Diodes whatever subs equal to or greater current and PRV.
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