Subwoofer Plate Amp Repair

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Do you have any knowledge and experience with diyAudio repair? If you do you could safely remove the plate amp and have a look for stressed components, capacitors and resistors etc. If you have dvm and soldering iron you should consider a diy repair. However, I would hasten to add that your Yung SD300-6 has a SMPS that holds High Voltages for a considerable time even after the power has been switched off and the cable unplugged!
Even if you don't undertake the repair yourself - having a look should be safe - at least you would then have an idea if it is just capacitors that need replacing or the entire Plate Amp.
Good luck.
 
Member
Joined 2010
Paid Member
"Instantly breaks the fuse...." suggests something more emphatic and probably invisible to the eye. If there was anything to be seen, it may be overheated resistors, but the more likely reason is failed power semiconductors. Testing the amplifier's output transistors is not terribly difficult but the switchmode PSU is another matter.

Don't even think about going anywhere near the power supply, powered or not, as nuryev explained. If a plate amplifier was fitted with a shielded SMPS power supply, it may be safe to work on the associated power amplifier but usually there is zero protection and it's not always obvious what is or isn't dangerous circuitry, both sides of the PCB, heatsinks included! Unless you can work safely with high voltage (380V + at lethal current) and have suitable rated safety tools and instruments, please don't poke about in there. :no:

Plate amps are relatively cheap assemblies, service tech rates aren't but they are both better and more certain, safer options for repairs. There are several UK repair guys here and they'll make themselves known if you let us know your approx. location.
 
Looks fine

Everything looks fine, nothing looks blown etc, I'm from leicestershire, anyone in nottingham/birmingham/Loughborough would be fine.

I can get a new one for $100 (friend coming back from america) so maybe just buying a new one is cheaper?

Don't want to risk death for £66 ish haha, if I take pictures would that help?

Thanks
 
Very often it's the power supplies that go, but even that would manifest just about identically to blown output devices/chip. I hate to say this but for £66 you may as well get another one. It could take hours to find what's wrong. So, unless you've got a mate who knows electronics ...

Shame to chuck all those connectors, pots etc., and possibly even a decent supply.
 
It was definitely a very decent amp....I only ever used a 1.6 amp fuse (recommended 2.5) and still it would never struggle with anything, the peerless xls10 would give up long before it would.

It now won't turn on at all, fixed a new fuse (for the first time in months), doesn't draw any power at all-the previous fuse had not just blown but the glass had shattered.

Real shame....can't get the damn woofer out now! might have to partially destroy the box to salvage it, this has been a bit of a disaster all round....(the woofer screws just turn and won't pull out).

No local engineers in leicester/nottingham/birmingham that can salvage this before it gets messy?
 
Are you able to grip the head of the screws with a long nose pliers and turn and pull them?

I would suggest you go carefully and salvage the box -unless you are comitted to buying a new subwoofer - which makes the diy repair project a wasted exercise. You don't want your diy solution to create a new problem. If you are able to safely remove the plate and take some pics and email or post them here I could tell you what to look for - but it can be dangerous. Looking but not touching any components is safest.

We can identify capacitors, resistors and transistors that may be suspect.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.