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Does the KSC3503 package require a mica insulator to prevent shorting to the metal heat sync plate?

After a restore, what is the normal temperature of an 800B power transformer that has been cooking for a couple of hours?

C102 on the 800B schematic is 200 uF. 214 uF is within 10%. Have you tested the C102 can with an ESR meter?

Nice work @Freddie73 How difficult was it to replace those can caps under that bundled wire wrap overhead? How did you move the wires out of the way?

Right now I have a single resistor. Please see photo in post #15. What is the downside of a single resistor?

Hi Dave, I only added one resistor. Do you have a photo of the recommended approach with the second resistor installed? Thanks!

@BlackScholes - Tonebells used 2N5116...

For the two scope board JFETs (Q1201, Q1204), what is the correct (best) modern substitute part number? 2N5114, 2N5515, or 2N5516?

Why is 2N5516 not suitable to replace Q1201 and Q1204 (Marantz part # 34-1030)?

Is there a sub for the three scope board diodes? CR1201 CR1202 CR1203

Thanks was the pinout different than the Marantz originals? Did you have to shrink tube the leads or did they plug right in?

Is there any advantage of using 2N5116 vs 2N5114 when replacing Q1201 and Q1204?

Is 2N5114 this the correct sub for Q1201 and Q1204? Does anyone know a source for 2N5114? Mouser and Digikey are out of stock.

Nice work @BlackScholes ! Can you share you parts list for the scope board? Also, have you replaced your FM muting LDR? If so, which components did you use?

@tonebells is this the recommended part? https://www.mouser.com/ProductDetail/onsemi-Fairchild/KSC3503DS?qs=K0aVCp%2F7QwZFJOGYBADtRQ%3D%3D Or is there are more robust recommended part number that is a direct plug in?

@SoulSmileInc I had success with the 544SD replacements (yellow color).

Should the traces be jumpered when the PCB is that dark?

Thanks but are the heat marks in the photo from the resistors normal for the 18 scope board or indicative of a problem?

Mine scope is intermittent. Might be a cold solder joint. The back of the board looks baked. Is it normal for those two tan/orange 10K resistors (metal oxide or wire wound?) to discolor the board to this extent?

Does anyone know the modern day part numbers for the four scope transistors that have a pinout that will allow a direct mounting plug in to the board (instead of having the flying leads)?

I believe that means your LNT caps were manufactured the 22nd week of 2020. The eBay seller sold you 3 1/2 year old filter capacitors…

FYI. In case someone lands on this thread in the future from a Google search, here's a photo of the NOS Zenith branded 6DS4 Nuvistor. It looks like it was manufactured the 35th week of 1971. I believe 188 might be an EIA code which signifies GE manufacture. I couldn't find a manufacturer...

I received the NOS 6DS4 Nuvistor. It is branded Zenith and has an EIA code of 188, which indicates GE manufacture. I believe the Nuvistor production date may be 1971. Without any sophisticated test equipment, the NOS Nuvistor appears (based on magic eye closure) to perform about the same as...

Did you check the manufacturing date codes on all the capacitors the eBay seller sent you? If I recall correctly, Nichicon LNT date codes are usually "stamped" on the top of the capacitor (opposite end of the screw and vent). What year were they made? Did you replace all the caps in your...

How does it sound different than before?