5000X in need of some love..

[smurfer77]

Hi Ben

It is difficult to measure low ohm value emitter resistors with a normal multimeter, you have to take into account the test lead resistance in the measurement, and even then you won't get a very accurate reading. Try shorting the test leads on the meter and see what resistance reading there is - you then have to subtract that reading from any measurement you do on low ohm value resistors.

Cheers

John

Agree with John... and even by shorting leads and subtracting this value from measurement it's not going to be super trustworthy because the accuracy in that 0.2Ohm range is typically poor. I'm talking +/- ~0.1Ohms over even 0.2, with a decent Fluke depending on the lead type. I bought a 4-wire bench multimeter after getting frustrated with that stuff...

 

[AnalogueBen]

Spot on with the advice here, I found I have 0.5 ohms in lead resistance, one nifty feature on my fluke though is the REL (relative) button which zeros the reading of the shorted leads thus giving a better reading. Never heard of a 4-wire bench meter, sounds like an accurate tool. Thanks.

 

[AnalogueBen]

Hey all,
Well it's been a successful afternoon for me, the 5000X is now punching out the tunes very nicely I think the best part was that the FM started working again, as at first there was nothing just AM.

What I've done since it arrived is..

• Good cleaning
• Replacement of filter caps
• New outputs and mica
• Removed preamp board to throughly deoxit all pots and all other switches
• Removed main amp boards, reflowed all solder joints
• Removed all soild 1/2 watt resistors and replaced with KOA carbon film.
• Replaced cement resistors
• New trimpots 20:1
• Bias and center voltage set

I'll give it a few weeks before I drop in a pair of 4700 uf Nichicon KG's and probably won't recap the rest for some time as well. Just want to notice changes one by one before going full recap, thinking this approach might teach me a little more about sound improvements and restorations in general. I will say though, it's some work to remove the boards on this model and if I go that far in again the caps will be changed out..!

I just need to clean up the shafts and gears in the tuner assembly because it's stiff and I'm assisting with its movement.

Cheers for the advice along the way