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I am repairing a Sony DA3000ES which seems to have one blown channel (displays Code 22 : Protection mode and powers off)
Tested the transistors found one is shorted. DigiKey seems to have this part listed here: https://www.digikey.com/en/products/detail/vishay-siliconix/SUP18N15-95-E3/2623095 which states these are 150v 18amp 88w but it’s obsolete, the substitutes show a 150v 17a 80w version and a 200v 18a 110w version.
Will these work as a replacement? (I highly doubt the 17a one would cut it)
Also it seems these are in pairs on the receiver will these substitutes work to replace just one? Or should I replace the pair so they are matched?
Be advised that “substitute” is a term that has substantially different meanings to different people…
Can’t say yes or no, for a variety of reasons:
Section ii.15 of the terms and conditions stipulate that that it’s the purchaser’s responsibility to determine suitability for use. That is necessarily so because:
There’s no telling from here what else might be busted, which is quite likely. If one’s concept of “work” means “replacing will restore function,” then in that case even the original part number would not “work”.
Without understanding the original criteria for device selection, one has no basis for making judgement calls as to what variations from the original might be tolerable.
Actually it’s probably not a bad option to consider, owing to the fact that FET drain current ratings actually mean something very much different than the casual observer may expect.
Can’t really comment, for similar reasons as above. Any repair effort one would undertake without first developing a working knowledge of the design is a dice roll.
The Q1683 MOSFETs in your picture are part of a half-bridge digital driver. In many respects, they are similar to the motor driver I described in this article.
Matching: IMO, this is not necessary as we dealing with a digital circuit not analog.
Replace both: Recommend replacing both and potentially the HIP21011BZT. It’s been my experience that failure of any MOSFET will compromise the other and often the driver.
Which MOSFET: Generally, the more capable MOSFET will work. We are dealing with a high frequency switcher where the MOSFET and it’s switching characteristic e.g. capacitance, speed, etc. However, deviation is not recommended. Given the devices mentioned in your original post, I would recommend selecting the device with similar gate capacitance and turn on/off times. This is generally safe if we assume conservative Sony engineers.
Be sure to verify pinout and inspect the thermal interface.
Thank you for the detailed reply, it is very much appreciated.
A bit more background on the problem, from what I gather the speaker wires on the one channel touched while the unit was on, the receiver then went into protect mode and shut off. (I assume because of this protect mode, not much damage would have occurred especially since only the one of the pair seems shorted. But that is just a guess.)
Any tips on how to test the driver IC? It is much harder to remove/replace as I am looking at it now, and it’s surrounded by a few SMD resistors & caps that are extremely close. So I only want to replace it if necessary.
With the MOSFETs removed, we may be able to see the square wave drive signal for the lower MOSFET. Unfortunately, the upper drive signal will not be observable - in fact, without a fully functioning circuit, the “bootstrapped” will not be present effectively starving the upper driver.
It’s a yucky situation where it either works or it self-destructs. That’s why I usually replace both MOSFETs and driver.
Given your constraints, you could replace the MOSFETs and cross your fingers. With all the usual caveats of potential destruction of the new MOSFETS and potential damage to the PCB.
Consider purchasing a few spare MOSFETS and the driver for a second attempt.
Sorry, that’s the best advice I can give. Makes me wish we had a good old 6L6 amplifier to troubleshoot.
I replaced the two dead “SUP 18N15-95”'s (Unfortunately since I could not find exact matching spec ones on DigiKey I ordered “exact” model # ones from china), they arrived I installed them. the receiver powered on and worked fine. However after maybe 10 or 15 mins it went into protect mode error 22 again and I noticed it smelt hot, touching the heatsink for those dead transistors was hot enough to burn me. (The other heatsinks are hot but not like that one). Is it possible the [HIP21011BZT] would cause this? I mean the receiver worked… which would imply to me the HIP21011BZT was ok… however since they ran so hot it implies these 18N15-95’s were not up to spec and sadly might be fakes. Any feedback would be great thanks again!
There is a possibility that the HIP21011BZT could have been compromised when the original MOSFET went out and I see @APDahlen had mentioned that could be an issue.
