Author Topic: Service? Why? How?  (Read 723 times)

Offline GECO

Re: Service? Why? How?
« Reply #15 on: August 10, 2018, 07:59:41 AM »
some servicing taking place


Sent from my SM-G930F using Tapatalk


Offline Coenoes

Re: Service? Why? How?
« Reply #16 on: August 10, 2018, 08:08:14 AM »
Wow. That looks interesting

Sent from my SM-G950F using Tapatalk


Offline ALF

Re: Service? Why? How?
« Reply #17 on: August 10, 2018, 09:54:38 AM »
My trusted testing/service tool is my Tectronix Huntron Tracker, I inspect every capacitor with this unit if it fail the test I replace it and if it tends to fail in the future I also replace it. Now and then I pick up diodes with small forward or reverse leakage current even while the unit is working fine then I still replace it, so servicing/bias and DC offset adjust can be a time consuming job but it can prevent future poofs   
"the fostex thang".....

Online Shonver

  • Trade Count: (+8)
  • AVForums Grandmaster
  • *****
  • Posts: 10,366
  • Total likes: 5
  • Criss-cross rhythms that explode with happiness
    • Elipse (under construction)
Re: Service? Why? How?
« Reply #18 on: August 10, 2018, 10:34:17 AM »
There is a grey overlapping area between fix, tweak and service. Especially on vintage equipment. On one project I replaced the caps in an amplifier, plus all small resistors. But the amp had a recurring noise problem in one channel, which this >90% revamp did not fix. I never got to find the offending component, but I did replace all the small-signal transistors on the main board, which made a clear improvement in basic noise levels in both channels. Sometimes, as in the case of these transistors, the original parts used are not the best.
________________

DON'T PANIC
Capie

Offline IlkoAlexandrov

Re: Service? Why? How?
« Reply #19 on: August 10, 2018, 07:18:03 PM »
If i may with my limited experience in this, and fully agreeing with all above - who do it not like me - thinking of it .. Yet, with >30 years building and braking boards and having soldered enough ICs to puke :

2 broad categories : Valve, solid state / sand

Valve in order of service attention : Valves - are they OK? Electrolytics, some resistors exposed to heat OR on the signal path, resistors very close to the output / power valves - measure well and replace at 1st doubt. AC fuse : remove completely or replace it with a fresh no-glass one. Trim pots : bias trims - cleaning and a fixed value high Q resistors perhaps? Volume control cleanup in integrates. All RCAs - Nordost (?) cleanup solution. Old valve amps : valve contacts cleanup - both on female and on valve side. Very aging wires on the signal or AC / DC path inside ?? Replace it ! Another last minute update asb ! All HT and Heaters - are they as they should be and why not if they out ?

SS in order of service attention : Electrolytics and some resistors exposed to heat, only in AA, eg Pass. AC fuse : replace it with a fresh no-glass one. Volume control cleanup in integrates. All RCAs - Nordost cleanup solution.

There is some more but i'll stop here, out of respect for some people here who know better - at the very least.

i

« Last Edit: August 10, 2018, 07:51:23 PM by IlkoAlexandrov »
Less is More
Nothing other than Exclame must come between You and the Music, period. So if the lights are out it is you and the music!

Offline wanda

Re: Service? Why? How?
« Reply #20 on: August 11, 2018, 09:11:56 AM »
Everything and everybody needs service. The question is what type of service.
the person who has a problem has the solution