Ampeg B100R again...

[mtlbasslad]

IC1 Pin1 .002 VDC Pin7 -.001 Pin8 .003...

[g1]

I think that the 9V at TP4 may be coming back from IC2. And if IC2 is fried that would explain why the +/-20V rails are skewed.
At this point I would just snip out IC2 (they're cheap) and see if TP4 goes to 0VDC. If it stays at 9V then replace IC1 as well.
I say snip out because the traces are usually pretty flimsy (or double sided board) and it's a lot easier to de-solder and remove the pins if they are just cut off. For cheap IC's on newer style boards, that is often the best way to go.

[mtlbasslad]

Guess I'll order some IC's

[mtlbasslad]

Checking Digi-Key & Mouser - there are many iterations of NE5532 & TL074 - with the form I need not much available, hmm

Oh wait, Newark has some. What is the difference between all the variations?

[Enzo]

NE is manufacturer specific. Looking for 5532 op amps in Mouser and in a DIP package, they have four choices in stock.

Looking for TL074 op amps in 14 pin DIP Mouser has six choices in stock.

[mtlbasslad]

Thanks Enzo, I was searching for NE5532 - a search for 5532 gets better results. I learn something every time you post to me.
Another 50 years I should be much wiser...

[mtlbasslad]

g1 - I've ordered the parts from Mouser, added some sockets for the IC's & new insulators for the TIPs. Shipping $20 now, even more expensive than Newark ($12).
Let's see if I can get the IC out without destroying the board... Thanks for your help so far - don't think we are out of the wood yet though.

[g1]

g1 - I've ordered the parts from Mouser, added some sockets for the IC's & new insulators for the TIPs. Shipping $20 now, even more expensive than Newark ($12).

I know the pricing and stock is a little bit poorer, but in Canada Digikey has the best shipping. $8 flat rate for delivery usually the next day or two. You have to use the .ca website. I believe they have a warehouse in Canada now, so no border or customs delays. Mouser was sometimes taking 2 weeks for me.
For US customers, I think mouser has the best options, more stock, and a bit cheaper pricing.

[mtlbasslad]

I looked at Digikey, Mouser & Newark - some sites had some things but not all, so I went with Mouser (CA) who had all the parts. I decided to add IC sockets & new insulators for the TIPs.
Tried your suggestion about clipping the leads on the ICs - my clippers way to big so unsoldered the 5532... Parts will be here Wed maybe, stand by for updates.
PS 'north of Fargo' - are you in The Peg?

[g1]

are you in The Peg?

No but I have lived there. I'm out in the country now down south of there near the border.

[mtlbasslad]

Parts arrived this aft - soldered in socket for 5532, checked no shorts & all pins contacting (those traces are very thin). Plugged in 5532 & tested...
TP5 is now -15VDC TP6 -15VDC Pin 4 -17VDC Pin 8 -23VDC.
Didn't get any farther time to make anniversary supper...

[mtlbasslad]

Joan loved the steak/frites with fried onions...

TP4 is still at -9.7VDC - guess I'll pull IC1 tomorrow...

[mtlbasslad]

Pulled IC1 & soldered in a socket, installed new IC1

TP4 is still -9.7 VDC ugh... TP1 -0.2 TP2 +13 TP3 -12
A bit discouraged here -what next?

[glebert]

Curious that TP1 went from being 0.002V to 0.2V when you didn't change anything there. I would be measuring voltages at the input of IC1 (pins 2,3) with no input.

[mtlbasslad]

glebert - thanks for checking in and welcome to my nightmare...

IC1 Pin2 +0.2VDC Pin3 +0.2VDC