Pardon raising this thread from the dead.
I have the same problem, a PDR-12 (from 2001) with the same two resistors burned. Mine look like different resistor values than yours, though. The resistors on mine seem to be two of the same kind in sequence: red, black, white, and gold. But I though white couldn't be a multiplier...There are multiple accounts of resistors in these positions burning on PDR-12 and the PDR-10, but none with resistors that look like what I've found on my PDR-12.
Here are some photos.
I really hope somebody can direct me towards an answer:
What type of resistors are these?
I have the same problem, a PDR-12 (from 2001) with the same two resistors burned. Mine look like different resistor values than yours, though. The resistors on mine seem to be two of the same kind in sequence: red, black, white, and gold. But I though white couldn't be a multiplier...There are multiple accounts of resistors in these positions burning on PDR-12 and the PDR-10, but none with resistors that look like what I've found on my PDR-12.
Here are some photos.
I really hope somebody can direct me towards an answer:
What type of resistors are these?
Yeah wierd ! Maybe it's the other way round ? White,Black,Red, Gold = 9K
https://www.eeweb.com/toolbox/4-band-resistor-calculator
As the resistors are burned, the values could way off. But, check them anyway, out of circuit, & see if they are close to 9k. If so, try changing them. They look like 1W carbon devices from here.
https://www.eeweb.com/toolbox/4-band-resistor-calculator
As the resistors are burned, the values could way off. But, check them anyway, out of circuit, & see if they are close to 9k. If so, try changing them. They look like 1W carbon devices from here.
Tomorrow I will pull the resistors and measure them out of circuit. I measured them while still in the board this afternoon, and got 2k ohms for the both of them. I had to look up how to interpret my multimeter readings on google (i'm in ee preschool, an electric toddler).
The pcb says PDR-12 as well as PDR-10, with the PDR-10 blacked out with marker. At first I assumed this means they use the same components as Rick's PDR-10, in his retro radio posting. This would be, as Nexus said earlier, "2k7 and 5k1 in series." How likely is it both models used the same components? Also, he is on 240v UK power. Would the resistors be different in a model made for 110v US power, or would some other component compensate for this difference? Would it be dangerous to try out these components?
root1657 of imgur helpfully pointed out these are most likely not the original resistors, judging from the sloppy soldering and positioning.
lnx64 of imgur pointed out they are not “burned,” but that they have gotten hot. I hadn't seen a truly "burned" resistor until he shared an image in the comment section of my imgur post.
What I think happened: the subwoofer broke down, somebody replaced the original resistors, poorly, then the new ones got toasty, and the subwoofer stopped performing again.
I wonder why the resistors are getting so hot? I just learned about the Capacitor Plague of the early 2000s, and thought the two big capacitors by the transformer could be toast. They aren't busted open and leaking electrolyte though. The tops are intact, and flat. Maybe a tiny bit convex? They are the original, Paradigm-branded capacitors. 5600uf, 50v, 85 degrees c.
I reached out to paradigm customer support to find out the resistor values. I hope they reply soon.
I hope to update this, until I've completed this PDR-12 project. I like the idea that the next person to come across a PDR-12 in a thrift store might see this and be able to rehabilitate it.
The pcb says PDR-12 as well as PDR-10, with the PDR-10 blacked out with marker. At first I assumed this means they use the same components as Rick's PDR-10, in his retro radio posting. This would be, as Nexus said earlier, "2k7 and 5k1 in series." How likely is it both models used the same components? Also, he is on 240v UK power. Would the resistors be different in a model made for 110v US power, or would some other component compensate for this difference? Would it be dangerous to try out these components?
root1657 of imgur helpfully pointed out these are most likely not the original resistors, judging from the sloppy soldering and positioning.
lnx64 of imgur pointed out they are not “burned,” but that they have gotten hot. I hadn't seen a truly "burned" resistor until he shared an image in the comment section of my imgur post.
What I think happened: the subwoofer broke down, somebody replaced the original resistors, poorly, then the new ones got toasty, and the subwoofer stopped performing again.
I wonder why the resistors are getting so hot? I just learned about the Capacitor Plague of the early 2000s, and thought the two big capacitors by the transformer could be toast. They aren't busted open and leaking electrolyte though. The tops are intact, and flat. Maybe a tiny bit convex? They are the original, Paradigm-branded capacitors. 5600uf, 50v, 85 degrees c.
I reached out to paradigm customer support to find out the resistor values. I hope they reply soon.
I hope to update this, until I've completed this PDR-12 project. I like the idea that the next person to come across a PDR-12 in a thrift store might see this and be able to rehabilitate it.
I measured the resistors out of circuit, they are 2k ohms. Jamie Z from Paradigm replied, and the 2001 PDR-12 resistors at R81 and R82 are 2k 2w. I'm going to replace these and the large capacitors. I am buying capacitors from digikey that are rated for 105 degrees, and 63v, as Rick of Retro Radio uses. I'd like to solder in resistors that can handle the heat, and hopefully last longer.
Is there a more robust solution than the original spec resistors?
Thanks for the help.
Is there a more robust solution than the original spec resistors?
Thanks for the help.
Glad you discovered what they are
Yes, use 5W types
Thank you! That led me to read about watt ratings for resistors. I just ordered a single resistor at 4k ohm 6.5w. I consulted rick's retro radio post, and skipping over two of the burned contacts seemed like a good idea. It's only 2.5w over the previous resistors dissipation, I hope that's enough. I'll update when I've installed the new pieces.
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