Pop and a fizzle

[T-wrecks]

Well I have had a partially WO phase linear 400 series 1, eight fin for awhile. It has a revE board in it. Mj21196g outputs, rca410 drivers. Original backplane assy and resistors. Original filter caps. It had Dons output relay board installed. Well resistor r10 on the relay assy has failed open. I have pulled the relay board so far. I'm in contact with done but thought maybe I could get some help here as well

 

[T-wrecks]

Here is a picture of the blown resistor

 

[T-wrecks]

Don said this resistor is supposed to blow if the relay fails but I also found this in the back of the board

There is a solder bridge between that resistor leg and speaker post

 

[Northwinds]

Are you the AK member that I referred over here this morning? If so, welcome to Phoenix. You will get answers here quickly

Ron

 

[WOPL Sniffer]

I'm trying to find my skizmo for the DCP. Don is on the road all the time and can be difficult to get ahold of, Be patient. Lee should be lurking about....

 

[T-wrecks]

Yessir, I've been around in the past, people may remember me. This is
me

 

[WOPL Sniffer]

Don said this resistor is supposed to blow if the relay fails but I also found this in the back of the board
View attachment 27339

What is it????

 

[WOPL Sniffer]

Yessir, I've been around in the past, people may remember me. This is
me View attachment 27340

You look nothing like your yearbook picture.

 

[T-wrecks]

Are you the AK member that I referred over here this morning? If so, welcome to Phoenix. You will get answers here quickly

Ron

Yessir that was me thank you

 

[WOPL Sniffer]

Well I have had a partially WO phase linear 400 series 1, eight fin for awhile. It has a revE board in it. Mj21196g outputs, rca410 drivers. Original backplane assy and resistors. Original filter caps. It had Dons output relay board installed. Well resistor r10 on the relay assy has failed open. I have pulled the relay board so far. I'm in contact with done but thought maybe I could get some help here as well

Have you started by ohming out your backplane (output/Pre) transistors? Did you blow fuses? Did your rent check bounce??????????????????????

 

[T-wrecks]

What is it????

there is a booger of solder right there

in this second picture I peeled the little booger back off from the binding post pad (the big hole pad)

 

[T-wrecks]

Haha, ok full disclaimer rent WAS a day late. And found one rail fuse is 250 volt, 5amp the other 125 volt, 5amp. Still both good however. So obviously that is not correct voltage fuse. Hmm. I have only pulled one driver so far. Can't find my precision sockets

 

[WOPL Sniffer]

Looks like it was supposed to be connected. It smoked the run off the board. It's possible when the resistor got hot it started melting solder. I would start ohming out the outputs. That DCP is toast at this time. It may be able to be repaired but with a blown trace, jumpers will have to be installed or??? I don't like to do that although some may. You need to ensure the amp is ok though. An ohm meter will get you a long way.

 

[WOPL Sniffer]

don't worry about the fuse. 5 amps is 5 amps no matter if it's 250v or 500v


An amp is an amp

 

[WOPL Sniffer]

it's time to do a full blown (no pun) wopl upgrade and get rid of the ancient backplane crap.

 

[T-wrecks]

I don't think there was a trace there, I guess I need to check the schematic lol. Also I'm pretty sure you can't test the outputs in circuit? Or? Can you?

 

[WOPL Sniffer]

I don't think there was a trace there, I guess I need to check the schematic lol. Also I'm pretty sure you can't test the outputs in circuit? Or? Can you?

Refer to your manual, the transistors CAN be checked in circuit but I prefer to pull them.

The way the pad is shaped, it appears to be connected.

 

[WOPL Sniffer]

look at your first picture. The speaker post pad is shaped as if it is connected otherwise it should be square like the others

 

[T-wrecks]

Edit:wrong pic
Here is a clearer picture

 

[laatsch55]

there is a booger of solder right there

in this second picture I peeled the little booger back off from the binding post pad (the big hole pad)

hould not be anything touching that pad on the solder side...
S