Look like STK modules, which are known to fail without reason...
Think of changing to modern types, chip amp or transistor amp if needed.
And caps which have experienced shorted diodes are frankly unreliable, as the STK modules are let us say, noted for going bang anyway.
Think of changing to modern types, chip amp or transistor amp if needed.
And caps which have experienced shorted diodes are frankly unreliable, as the STK modules are let us say, noted for going bang anyway.
They only fail if overheated and no pro-active service is done.
Otherwise they are reliable.
They run hot, and sometimes break loose from the PC board connections, resulting in failure.
Please explain what pro active service means, I have a Sansui with an intermediate section STK, and a Kenwood amp with a STK 4141 output stage.
You mean a regular inspection, tighten heat sink and so on?
Acceptable...
Sanyo was founded by the brother in law of Mr. Matsushita, and parts of Sanyo ended up in the Matsushita group.
Those modules may be OEM versions of STKs, and there are threads here about making equivalent modules.
But first the existing ones should be checked for life, or death, so to speak.
Acceptable...
Sanyo was founded by the brother in law of Mr. Matsushita, and parts of Sanyo ended up in the Matsushita group.
Those modules may be OEM versions of STKs, and there are threads here about making equivalent modules.
But first the existing ones should be checked for life, or death, so to speak.
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Being proactive with service in my view is things like checking solder connections on ALL heat-producing components - STK's, Regulators, Wire-Wound resistors, etc.
And doing a visual of the PC traces for any possible "dry soldering" which could eventually cause a failure.
Then, re-soldering/reflowing those joints to insure reliability.
I've been doing that for decades in the shop, mainly to prevent "call backs" possibly due to customer rough handling of their equipment.
Particularly with vintage equipment.
It's insurance.
The Technics pre and power sets like the SE-A1000 sell for silly money nowadays depending on condition now let me ask if you would pay top £££ for a SE-A1000 with a class D amp inside.
Would you ?
Oh I would repair it instead of scrapping it. I also would not pay much money for old stuff and "resale value" is not in my book. Quality of old amplifiers is often exaggerated and what to do when those modules are nowhere to be found? Do not underestimate the looks of devices that are a large part of the attraction factor. I have a history of repairing Marantz cult stuff that I would not even want for free like the nearly always defective and almost irreparable SC-80 (the CD-80 however is one of the best CD players I have ever seen). Same goes for some Musical Fidelity devices with many a design imperfection and having at least 1 severe issue that despite that still are popular.
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Thanks for all the tips, after the weekend I'll go back to the device and measure the components.
Scrapping it isn't an option it's part of a bigger system
Scrapping it isn't an option it's part of a bigger system
@RS232 : Nobody pays silly money for broken units.
@Revoxis: Shift the thing away from refrigerator or whatever coil is on the left, it is a heat source, can reduce life.
And after the amp is brought back to life, do go over the rest of the components and do a pro active / preventive service like Wiseoldtech says, insurance of sorts.
@Revoxis: Shift the thing away from refrigerator or whatever coil is on the left, it is a heat source, can reduce life.
And after the amp is brought back to life, do go over the rest of the components and do a pro active / preventive service like Wiseoldtech says, insurance of sorts.
Ah that refrigerator wasn't connected and was only there for a day, due to a new one.
I am planning to go over the components once its fixed, i'm still waiting for the new parts. in the meantime does anyone know how can safely measure the ohm of those large 10000uf 63v caps?
I'm not 100% sure if i need to desolder them first to do the check or short them first? and if so which pins?
Would this be any good after its working again? Technics SE-A1000 / M2 Upgrade Kit Audio Capacitors
The problem when doing things in the dark is that an forming an opinion is hard and it is influenced by others opinions too fast. That gives an unpleasant kind of incertainty especially if you want also to prove that the old caps are old (they are but I determined this empirically) but lack the knowledge/experience to measure them.
Maybe it is then just a matter of replacing them for the ones you pointed at yourself and be done with it. The amplifier will then be like it is new. If “resale value” and “original” are carved in stone you could keep the old ones and never look at them again.
You can’t go wrong with Nichicon LKG but still make sure to use better diodes than wimpy 3A rated ones. I think I would even search for 8A ones like SR8200. It may be a classic but I would prefer a classic that keeps working.
Maybe it is then just a matter of replacing them for the ones you pointed at yourself and be done with it. The amplifier will then be like it is new. If “resale value” and “original” are carved in stone you could keep the old ones and never look at them again.
You can’t go wrong with Nichicon LKG but still make sure to use better diodes than wimpy 3A rated ones. I think I would even search for 8A ones like SR8200. It may be a classic but I would prefer a classic that keeps working.
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With a simple digital multimeter at the 200 Ohm range (continuaty test) put the test leads on the terminals of the capacitor.
You should see the Ohms go up until end of range. Now reverse the test leads. The Ohms now go down to zero and opposite end of range.
Do this only if you are sure the elco's are fully discharged.
This gives an indication that the capacitors at least are not open or short circuit.
Also, this indicates that no short circuit is present in the power IC.
Remove the 4 power rectifier diodes ans replace them with 5A types.
In my experience, the big power supply elco's do not get defective that often.
Put a 100 W lamp in series with the mains supply.
Then connect power without speakers. If the lamp does not glow brightly and if after a few seconds the speaker relay(s) click, chances are that the amp could be O.K.
If not, the power IC is suspect.
That is how I would staart to tackle this problem.
You should see the Ohms go up until end of range. Now reverse the test leads. The Ohms now go down to zero and opposite end of range.
Do this only if you are sure the elco's are fully discharged.
This gives an indication that the capacitors at least are not open or short circuit.
Also, this indicates that no short circuit is present in the power IC.
Remove the 4 power rectifier diodes ans replace them with 5A types.
In my experience, the big power supply elco's do not get defective that often.
Put a 100 W lamp in series with the mains supply.
Then connect power without speakers. If the lamp does not glow brightly and if after a few seconds the speaker relay(s) click, chances are that the amp could be O.K.
If not, the power IC is suspect.
That is how I would staart to tackle this problem.
10,000 uF 63V are the power caps (just above the kit). They are not in the kit but they can be added to the order. You are right, they are mentioning all caps and then mention the power caps are not included. Then they list 2 x 22,000 uF 63V!?!?
It is probably better to order them elsewhere.
It is probably better to order them elsewhere.