HELP! Rescuing Dad's old PL400 S2 (pics)

[lightfall]

PL 2000 series 2. The thump was somewhat intermittent but not regular. It stopped, I think, when I didn't plug the turntable and amp into the switched outlets located on the back of the pl2000s2.

I will give a more clear account of this when I return home!

 

[laatsch55]

You really shouldn't plug anything into the pre-amp power wise....

 

[laatsch55]

Hard on pre-amp power switches....

 

[lightfall]

I was just trying to follow those phase linear instruction manuals haha, I think you are right though!

 

[laatsch55]

Been there, done that, replaced switches....

 

[lightfall]

I will start by plugging all units into a surge protector separately, do you recommend I do something to the switched power sockets in the preamp or is that not necessarily beneficial? Do you suppose I damaged the preamp by doing so? I had the volume at very low levels for a very short period of time. I better DBT that sucker just in case.

 

[laatsch55]

No you didn't hurt anything using the AC outlets on the pre....

 

[laatsch55]

Leave the sockets empty...it's cool...

 

[gadget73]

Does the 2000 preamp have the power relays like a 4000 does? Those put almost no load on the switch, but I still wouldn't trust it to handle the amplifier power load. Should be OK for the turntable though. I just don't like running a lot of load through single cords. It seems like a bad idea to me.

Also, does the 2000 use those cards like a 4000? I had lots of noise problems with my friend's 4000 that was entirely related to many many broken solder joints. The first time I tested it, it made a cracking noise so loud I thought it was going to blow my speakers.

 

[lightfall]

I am going to try to see what the 4000 looks like, I am not sure what cards you are referencing. The unit was incredibly clean, aside from a cracked solder joint on one of the RCA jacks that I repaired it looked pretty immaculate. I did take a close look for cracked joints, but it would not hurt to take another look.

 

[lightfall]

This 12 hour shift is killing me, I want to get home and test it NOW

 

[gadget73]

I dug up the 2000 service manual, and it does not appear to have cards like the 4000 has. Thats a good thing, fixing that thing was a huge pain in the ass.


http://thecarversite.com/shell-manuals.htm

iff'n you'd like a copy of the manual for that. The owners manual and the service manual are both there.




These are the guts of a 4000. You can see all of the cards.

here's the bottom side. The one I fixed needed ALL of those joints re-soldered. The cards are not supported, so they put a lot of strain on the main board.

 

[lightfall]

Interesting: I hooked up my phone's audio player to RCA on the aux input and thought for a second I was getting really nice, clear audio. Upon close inspection I was only getting sound from the right channel. The LED indicator on the amp for the right channel showed appropriate dB output. When I tried the balancer pot on the preamp I noticed that I got a hollow, tinny, sound from the left channel with no bass.

Now this next part I am not sure if it is correlation or causation but I unbypassed the tone control button and adjusted the bass knob for the right channel. A couple seconds after I got a few THUMPs with corresponding spikes on the right channel dB meter. I quickly stopped with the knob thinking it was a scratchy pot and the thump was somehow the pot scratching. The thumps continued somewhat more regularly and I panicked and shut the unit down. Once it was powered off a final loud THUMP occurred after shut off on the left channel.

 

[lightfall]

Also, I did not mention, the entire time I got no dB reading on the left channel, even when I could hear the tinny sound and adjusted the volume knob all around on both the pre and amp.

I will take a closer look at the 2000 internals again for broken solder points but I THINK it is supported inside. My wife's family is in town visiting through the week and I work 12 hour shifts this week so I will have to steal every trouble shooting moment.

 

[laatsch55]

Do we know if the amp is OK?

 

[lightfall]

5.6.1 of the service manual suggests that loss of one channel when tone circuit is in requires replacement of z3 and/or switch assembly. Now I need to see if both channels work when tone is in...hmm.

 

[lightfall]

I am retesting the amp now before I do any more goofing around.

 

[laatsch55]

Have you heard the amp through speakers , from both channels?

 

[lightfall]

ARGH DBT glowing bright on the amp. Preamp is DBT OK. Fuses OK on both.

Talk about disheartening.

 

[lightfall]

Thebamp produced good sound on the right channel, quiet hollow tinny sound on the left. Total time on was probably less than a minute and low volume overall.