Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

A501 / Z501 Luxkit Amplifier schematic
A501 / Z501 Luxkit Amplifier schematic
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th March 2019, 08:29 AM   #111
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
A501 / Z501 Luxkit Amplifier schematic
Working through the posts...

The only result that mattered was the behaviour of the amp with pin 7 grounded. It seems like doing this did indeed change the behaviour (which is good) but what we really needed was the voltage check of offset.

You could do that by anticipating that the click was the speaker relay connecting correctly and so wiring the meter across the speaker sockets and seeing what happened.

This result is a big step forward though and hopefully shows the main amp is basically OK. The circuit also seems to show a single LED, not a bi-colour type.

---------------------------------

Discharging caps. Normally the circuit itself will do that. Just check to make sure there is no high voltage across them. Anything under a couple of volts is OK to begin working on the amp. To manually discharge a large cap use a resistor appropriate to the voltage. A 4k7 2watt carbon type should cover most situations on solid state stuff.

-----------------------------------

The shiny green is a mask which we call solder resist. The board still looks like a phenolic resin type to me and will have a distinct smell as you solder on it. The discolouration in response to long term heat is perfectly normal though.

The soldering looks pretty much par for the course tbh. Look at the last pictures in post #1 here which show the kind of thing to be aware of. Some of those joints on your board look very suspect but I would beware at this stage of doing more remedial work... try and diagnose and fix the issue at hand first.

Sony CDP790 and KSS240 Restoration Project

-----------------------------

The cap marked 471 is a 470pF polystyrene type. Its 4 and 7 and then 1 zero as the multiplier. 473 would be 47,000pF or 47nF (nano) or 0.047uF.

------------------------------

So where next

Well I guess you have to replace that opamp and also clean the top area of the board around the opamp gently. The voltage you measured on pin 7 earlier is the one thing I have doubts over... because I would have expected it to be stuck more toward the supply rail than an indeterminate voltage.

That doesn't change anything as far as we are concerned, its just a case of,

1/ Is the opamp alone genuinely faulty? It would still be last on my list of suspects tbh.

2/ Is the problem contamination on the top of the board affecting the high impedance circuity of the opamp? This means replacing the opamp may well fix the issue as contamination is automatically burned off and removed.

3/ Is the problem one of the passive parts around the opamp. It happens, however unlikely.
  Reply With Quote
Old 16th March 2019, 12:37 PM   #112
druidaudio is offline druidaudio  Wales
diyAudio Member
 
Join Date: Feb 2009
Location: Wales UK
A501 / Z501 Luxkit Amplifier schematic
Quote:
Originally Posted by SONDEKNZ View Post
@druidaudio

Can you confirm what the normal "PLAY" state of the Control Console LED is on your Z501 please? Is it solid red? Or does it turn solid green?
I no longer have my Z501, so cannot check and don't remember, but the manual says it should go from blinking red to continuous, so I assume this is also red?
Sorry I cannot be more helpful.
  Reply With Quote
Old 16th March 2019, 08:57 PM   #113
SONDEKNZ is offline SONDEKNZ  New Zealand
diyAudio Member
 
SONDEKNZ's Avatar
 
Join Date: Jul 2013
Location: Auckland
Default Seems like SOLID RED LED = "PLAY"...

Thanks DRUIDAUDIO. No drama.

By all accounts, it seems like a solid red LED = "PLAY".

I have several different amps, so I can't quite recall either.

Let's just see how it plays out...
  Reply With Quote

Reply


A501 / Z501 Luxkit Amplifier schematicHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Luxkit Avance Z-504 sismofyt Solid State 8 17th January 2018 01:38 AM
Luxkit A1020 need help!!! huytienluu Tubes / Valves 13 27th June 2015 06:07 AM
Luxkit A503/Z503 curcuit schematic/build instuction wanted Frank J.Y. Lin Analog Line Level 0 27th December 2006 10:36 AM
Need help wiring an SAE A501 for 220V testlab Solid State 3 21st November 2006 08:47 PM
How to use SAE A501 Amp, 1980's 321uam Solid State 2 25th September 2004 08:32 AM


New To Site? Need Help?

All times are GMT. The time now is 06:24 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki