Hi Guys,
I am Liem from Indonesia.
I own Threshold S/300 and recently accidentally I blew one of the fuses (positive rail) after I unplugged the interconect without turning the unit off first.
After I replaced the fuse and turned it on, it blew my speaker.
When I checked the DC voltage of the speaker output terminal, I found 61 Volt output!
I wonder what has caused this problem.
What parts should be checked or replaced?
Thank you for your advice.
Best regards,
Liem
I am Liem from Indonesia.
I own Threshold S/300 and recently accidentally I blew one of the fuses (positive rail) after I unplugged the interconect without turning the unit off first.
After I replaced the fuse and turned it on, it blew my speaker.
When I checked the DC voltage of the speaker output terminal, I found 61 Volt output!
I wonder what has caused this problem.
What parts should be checked or replaced?
Thank you for your advice.
Best regards,
Liem
Moved to Pass Labs 
liem
post well lit and big enough pictures (1200px at least) , schm of your particular amp if you have it, so we can start from there
post well lit and big enough pictures (1200px at least) , schm of your particular amp if you have it, so we can start from there
Most likely you have blown one or more output transistors.
It might be possible to locate which one by toasted emitter resistors.
It might be possible to locate which one by toasted emitter resistors.
Blown Parts
Thank you Sir for moving me to Pass Lab forum.
Thank you very much Mr. Pass. I am glad to get response from you. Sorry for late in responding back.
I herewith would like to attach a picture showing the blown parts after I asked a repair person to open the S300.
Can you confirm if the parts in this PCB will be the only parts to repair?
The technician also checked the output transistor (PNP and NPN) and found they were in good conditions.
Thank you for your advice.
Best regards,
Liem KF
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Thank you Sir for moving me to Pass Lab forum.
Thank you very much Mr. Pass. I am glad to get response from you. Sorry for late in responding back.
I herewith would like to attach a picture showing the blown parts after I asked a repair person to open the S300.
Can you confirm if the parts in this PCB will be the only parts to repair?
The technician also checked the output transistor (PNP and NPN) and found they were in good conditions.
Thank you for your advice.
Best regards,
Liem KF
Attachments
impossible to answer just on base of that picture
if tech checked all OS transistors and they're good, that's great
what you need now is to clean that pcb from burns (alcohol and cotton swabs) and check all components .... practically common troublesooting routine
locate schematic ( they're around) of your exact amp FE, inform which parts are blown
if tech checked all OS transistors and they're good, that's great
what you need now is to clean that pcb from burns (alcohol and cotton swabs) and check all components .... practically common troublesooting routine
locate schematic ( they're around) of your exact amp FE, inform which parts are blown
Blown Parts
Dear Zen Mod;
Thank you for your suggestion. The technician told me that these parts needed replacements: MPS U10, U60 A42 and A92 and some capacitors and resistors.
Hopefully only these parts that need replacement.
In regards to resistors and capacitors, please suggest the best one to use as replacements.
Thank you.
Dear Zen Mod;
Thank you for your suggestion. The technician told me that these parts needed replacements: MPS U10, U60 A42 and A92 and some capacitors and resistors.
Hopefully only these parts that need replacement.
In regards to resistors and capacitors, please suggest the best one to use as replacements.
Thank you.
you can't trust your repair guy?
anyway, here's the sch. if you need it
btw. I'm sort of tech, and last thing I wish during repair of anything , is customer babbling about parts
refused further dealing not once......
anyway, here's the sch. if you need it
btw. I'm sort of tech, and last thing I wish during repair of anything , is customer babbling about parts
refused further dealing not once......
Quality components for Threshold S300
Hi Zein Mod;
Thank you for your sending me the schematic diagram.
My technician has limited knowledge about the High End audio unit.
All he knows is to get the unit sound again and he has no concern whether the sound quality after repair degrades or not.
So, I need advices about the quality components to bring the unit sound quality back to its original or better...
Thank you and best regards,
Liem KF
Hi Zein Mod;
Thank you for your sending me the schematic diagram.
My technician has limited knowledge about the High End audio unit.
All he knows is to get the unit sound again and he has no concern whether the sound quality after repair degrades or not.
So, I need advices about the quality components to bring the unit sound quality back to its original or better...
Thank you and best regards,
Liem KF
standard metal film resistors
no need to change solid/block caps
replace Tantalum caps, if there, with modern electrolytic - decent branded (Panasonic, Elna, Nichicon, whatever
if needed, ask again
no need to change solid/block caps
replace Tantalum caps, if there, with modern electrolytic - decent branded (Panasonic, Elna, Nichicon, whatever
if needed, ask again
Component for S300
Dear Zen Mod;
Great! Thank you for your information. I really appreciate that.
Best regards,
Liem
Dear Zen Mod;
Great! Thank you for your information. I really appreciate that.
Best regards,
Liem
Tantalum
Dear Zen Mod;
To replace Tantalum Cap, is it better to use Mylar 0.15uF 50 v or elcap MKP 0.15uF 250 V?
It's hard to find Elcap 0.15uF from Elna or Panasonic or others here.
Dear Zen Mod;
To replace Tantalum Cap, is it better to use Mylar 0.15uF 50 v or elcap MKP 0.15uF 250 V?
It's hard to find Elcap 0.15uF from Elna or Panasonic or others here.
Curious regarding tantalum caps. I know the old wet tantalums like the ones used back in the '80s suck, but the newer solid tantalums actually seem pretty good?
