Need help verifying if the PL14_20 Control board kit will work in my 400S2

[dmccan13]

Can anyone tell me if the PL14_20 control board kit will work in my unit? The markings on the board in there show PL36 I think. I just want to verify before I drop the coin.

Thank you!

 

[Gepetto]

Absolutely it will

Replied in other thread. The PL14-20G1 is universal in ever PL400 or 700 ever made, regardless of generation.

Changes PL made were really cosmetic in nature, the basic design never varied much.

 

[dmccan13]

Thank you Gepetto! That helps a lot, still getting my sealegs here. That's all I needed, now I can order Been stewing on this for a couple days. That's what led me here. I appreciate the help

 

[J!m]

DAMN! Those resistors got hot.

 

[Gepetto]

DAMN! Those resistors got hot.

The technical term is toasty

 

[J!m]

Yeah, but I don't like my toast THAT dark...

That 880 board was the same shade I think.

 

[dmccan13]

What would make them get that hot to scortch the hell out of the board? I've ordered the WO board, but is there something else I need to be looking at? When I pulled the fuses the line fuse was fine but the supply fuses were both blown.

 

[dmccan13]

I don't want to fry the new board once I have it together.

 

[Gepetto]

What would make them get that hot to scortch the hell out of the board? I've ordered the WO board, but is there something else I need to be looking at? When I pulled the fuses the line fuse was fine but the supply fuses were both blown.

That toast look was a design feature of the PL36 board. They put the interns on that project.

Yes you likely have multiple blown output transistors if you have blown rail fuses.

 

[dmccan13]

Ugg, I figured. So a full backplane refit right?

 

[dmccan13]

What caused the fuses to blow and why did they not protect the transistors?

 

[dmccan13]

And thank you again for your help @Gepetto

 

[laatsch55]

What caused the fuses to blow and why did they not protect the transistors?

The transistors shorted and then the fuse blew....that's the sequence...

 

[laatsch55]

Ugg, I figured. So a full backplane refit right?

Depends on what you want to do. Do you know how to test a transistor?

 

[dmccan13]

The transistors shorted and then the fuse blew....that's the sequence...

I got you. Thank you. I was thinking the fuses protected them, so this helps.

 

[dmccan13]

Depends on what you want to do. Do you know how to test a transistor?

I don't but I'm decent at electronics, I can look it up. I'd still have to separate them from the circuit like caps right? So if I'm going to have to pull them all, I may as well replace them all while I'm at it. But I'm absolutely open to any advice. I veer off course regularly

 

[laatsch55]

While you are waiting on the board, dismount and test all outputs.

https://forums.phxaudiotape.com/thr...cs-thanks-to-markthefixer-and-echowars.10000/

 

[dmccan13]

While you are waiting on the board, dismount and test all outputs.

https://forums.phxaudiotape.com/thr...cs-thanks-to-markthefixer-and-echowars.10000/

Roger that, makes sense. Thank you

 

[laatsch55]

Got a good meter?

 

[dmccan13]

I'm decent, got a fluke 87. This is the guidance I need, so I appreciate it. I guess there are potentially NPNs and PNPs. I noticed 4 RCAs and 12 Motorolas (?). I'll look them up in the morning and start the process. What I haven't done before is solder joints that big. However this is good in another way, I need to pull the cooling fins off to finish cleaning, I think this was buried in a root cellar before I got it...