Derek92994's 700 Ser II White Oak conversion

[laatsch55]

I think they are going for 7.00 here Darc...haven't checked in awhile though..
A few emitter resistors wouldnt hurt. Ya got picos right?

 

[derek92994]

Yeah got picos. I will place an order soon, if you think of anything else that may be needed please let me know. Going to get a pizza then I will put the wopl back in the cabinet. Scotch, pizza and audio bliss

 

[laatsch55]

Bless ya kid!! going to bed..

 

[pennysdad]

Bless ya kid!! going to bed..

I wish I had a bed...

 

[derek92994]

I wish I had a bed...

You do, its behind all those amps and speakers.

 

[derek92994]

Been running the amp daily for a couple of days. I heard a pop before but dismissed it as a CD artifact. Heard a much louder pop just now, the amp continued to play music for the few seconds before I hit the power switch. This time it seems nothing blown, powered it up and down about 3 times, relays click, all normal (speakers disconnected just in case). Its making me nervous, so I will go back to spare amp tonight, and await further advice.
George (pennysdad) mentioned the transformer as a possible culprit, just throwing that out there, I personally have no idea myself.
Repair History: Rev D board replaced with Rev G1, 2 outputs (95’s, right channel) and 2 fuses replaced on 2 separate occasions, same symptom, loud pop from speaks.

 

[pennysdad]

not so much the transformer, but a 'hiccup' in the voltage supplying that supply rail.

 

[derek92994]

I should also mention one of the main caps has a dent in the bottom of it but it has run fine for 6 years.

 

[pennysdad]

I should also mention one of the main caps has a dent in the bottom of it but it has run fine for 6 years.

I've had a dent in my bottom all my life! Too late to do anything about it now!

 

[laatsch55]

Ok, get it opened up Darc. Power on and start feeling the heatsinks on on the predrivers and MPSA 42's...NOT the low voltage power supplies, they run hot anyway...

 

[laatsch55]

Do you have lower amp fuses we can put in for rail fuses?

 

[derek92994]

Do you have lower amp fuses we can put in for rail fuses?

No, what do I need?

 

[laatsch55]

2 or 3 amp would help if you do experience a short while testing instead of the 5 .

 

[derek92994]

Ok, get it opened up Darc. Power on and start feeling the heatsinks on on the predrivers and MPSA 42's...NOT the low voltage power supplies, they run hot anyway...

ok where are these components?

 

[laatsch55]

The TO-220's laying oin the back lower part of the driver board, the 42's are the 3 small ones in a row....
And then take low voltage measurements on each side...from the test points.

 

[derek92994]

I will go purchase some 2 or 3 amp fuses, they also have to be agx?

 

[laatsch55]

Yes, got a place handy?

 

[derek92994]

Should have. I will go to jaycar electronics.

i think i have found the parts you want me to test, pictured below. I will use a thermal gun.

im heading to electric shop now. Touch base when i get back

 

[laatsch55]

Yep...

 

[derek92994]