r/audiorepair

Hi everyone,

I’m trying to diagnose a failed StormAudio PA 200 Elite multichannel power amplifier from a home cinema system. I’m not planning to repair this myself, but I want to understand what a competent technician should check before I’m pushed into a very expensive replacement.

System context:

• StormAudio PA 200 Elite power amp
• StormAudio ISP 3D processor
• M&K cinema speakers
• AudioQuest Niagara 1200 power conditioner/surge protector
• Installed in Portugal, 220–240V
• Rear fuse marking: 220–240V: T5A L 250V

Failure timeline:

About a week ago, while watching a football match, the amplifier suddenly became much louder than usual. The rear fans sounded like they were running at abnormally high speed continuously for the whole session. I took a video at the time, and the front LED appears to be blinking/alternating red and green, or possibly yellow/red.

A few days later, the cinema was turned on again. After a few seconds, the sound stopped. Since then the amplifier appears completely dead:

• no front LED
• no fans
• no relay click
• no response to power cycling
• other equipment in the rack still appears to have power

The local installer suspects a power surge and is recommending replacement/upgrade, but I’m skeptical because the loud fans and blinking LED came before the total failure. To me it sounds more like the amp was already in some thermal/fan/protection/PSU fault state.

I have photos of the rear panel, fuse marking, internal layout, fans, etc. I don’t see any obvious burn marks or exploded components, but I’m not a technician.

My main questions:

1. For a high-power Class D multichannel amp that is now totally dead/no LED, would the first checks usually be IEC fuse, mains input, soft-start/inrush, standby PSU, and low-voltage rails?
2. If the T5A L 250V fuse is blown, what are the most common downstream causes to check before replacing it and powering on again?
3. Does the sequence “fans running full speed + blinking LED, then dead days later” point more toward thermal/fan-control/PSU/protection failure than a one-off surge?
4. Are amps like this usually repairable at PSU/module level, or are they commonly uneconomical to repair?
5. What should I specifically ask a local repair tech to test so I don’t get a vague “probably surge, replace it” answer?

I’m trying to find the most cost-effective route: proper bench diagnosis and repair if possible, rather than a €20k+ replacement of the system.

Thanks for any guidance.

I bought an Adcom GFA-5500 amp on eBay. It arrived with shipping damage, including broken speaker terminals, that might result in me returning it in any event. Because of that I haven't had a chance to try it yet to see if it's working right otherwise.

I took off the cover to see how the speaker terminals were attached and noticed these capacitors tops were domed a bit. Wasn't sure if that was normal or not a big deal or if it was a sign they were bulging and were either gone or on their way out.

Any thoughts?

I've had this guitar amp for 5 years and never had a problem with it. Nonetheless it has started to fail, specially when I try to use the clean channel it loses a lot of volume.

The function of the part is to alternate into the clean and overdrived sound of the guitar signal.

When I wiggle the switch it sometimes comes back to its normal volume, so I am almost 100% sure the problem is with the switch of the channel change.

I'd like to replace it but the problem is that I don't know a lot of electronics and I'm not sure what type of switch I should buy.

Hope someone can help me.

The photo of the switch is attached at the top of the post.

I really wish I could upload a video to show what’s going on better. But basically as the title says, I have this Philips MC235B that struggles to open when I place it upright, but once I lay it down flat it works without issue. I’m stumped as to why this is. The closer I open it towards a 90° angle the easier it is to slide itself open

I have a Marantz 1040 home stereo amplifier that is wired for European voltage, but I'm in the U.S. and my tech guy isn't available to convert it for at least a month.

Would it be a bad idea (for safety or sound) to get one of these so I can use it in the meantime, since my budget is a bit tight?

https://www.ebay.com/itm/318289801133

LiteFuze 300 Watt Step Up/Step Down Travel Voltage Converter, 220/110v to 110/220v

Not to open a whole can of worms, since there are so many conflicting ideas about safe wattage, but the Marantz officially lists at 125 watts of power consumption.

Any advice is appreciated!

Hello.

I got a carver stack for an insane deal and I love my TL-3200. Awesome quality. When testing the receiver I got however, this is happening. It won’t output any sound when hooked up to my TL-3200, and it just does this. When turning up the volume knob, it makes an extremely loud popping sound before cutting the buzzing for a second, then the buzzing comes back.

I got it to play sound once from the TL-3200, and the volume knob was very spotty. When turning the knob, static sounds came and it did not increase the volume like how it should, with random extremely loud and extremely quiet sporadic volume levels. It also kept on cutting out my left ear channel when adjusting the knob.

Am I screwed on this here? I’m quite new to audio repair.

Please excuse the awful ramshackle setup, but I'm testing some new wharfedale glendale XP2's, and one of the speakers has slowly started to die. It started to sound extremely tinny and then it died completely. I've tested the cables, switched them around and I've tested the amplifier separately. My friend said it could be the voice coil but any advice would be appreciated. (Also, this is not a permanent setup. I'm just testing the components)

I'm looking for some advice on an old VS2421 2.1 speaker system. It's a very cheap multimedia speaker set, but it has sentimental value so I'm trying to repair it instead of replacing it.

The issue is a constant low-frequency hum (I'd estimate around 100 Hz) that starts as soon as the system is powered on, even with no audio cable connected.

Based on previous advice, I replaced the main filter capacitor (Samxon 4700µF 35V, ~20 years old) with a new Nichicon PW 4700µF 50V 105°C(the big green top right of photo 1).

Unfortunately, the hum is still present. It may be slightly lower than before, but it's definitely still audible.

Here are a few observations:

• The hum is present in both satellite speakers and the subwoofer.
• The master volume control has no effect on the hum.
• The bass control affects the subwoofer. Increasing the knob increases the hum from the subwoofer.
• If I turn the bass control all the way down, the subwoofer becomes silent, but the satellites still have the hum.
• The subwoofer cone can be felt vibrating slightly from the hum.

I'm attaching a picture of the PCB.

Based on these symptoms, what would you investigate next?

Would you suspect:

• other electrolytic capacitors around the amplifier,
• the power supply,
• the bridge rectifier,
• or simply the design of this very cheap amplifier?

Any advice would be greatly appreciated. Thanks :-)

I have this old Technica stereo reciever that used to work great for me till one day it stopped making noise, and there was no more click on power up. I opened it and checked the relay, and sure enough, it has a big crack on its side. I can solder in a new one by myself, but I've been having trouble identifying a suitable replacement for it since they dont make this particular relay anymore. I dont want to risk frying anything by putting the wrong thing in here. Can anyone point me in the right direction?

Matsushita JR1a-DC24V-TV

AJR39004

https://www.soundstagenetwork.com/revequip/mirage_om5.htm?__cf_chl_f_tk=NCF2Ob4N5NeUITJsXd8I2d76Diz970SzF4lLblF5_Lg-1782955785-1.0.1.1-DTOGLz3qgq31Rn_MkFMdTYDt04mo_jYQKQj89ocChmM

Found a pair of Mirage OM-5s in the dumpster with the boards also removed but nearby. Basically, everything is there with the exception of one of the subwoofer mesh covers.

Initial testing:
I hooked both of them up, sent some sound through them via a good AVR. They sounded great... until the light on the front of each went red after about 30 minutes. Once this happens, perhaps it's in standby mode, but I cannot get the subwoofers to work again like this.

I do a total power off on the tower, wait a few seconds, and even then, I usually have to close whatever tab was playing music, power off the AVR, then start turning stuff on from the tower to the AV, it's kind of picky. The mids/tweeters still go, but the subs (2 on each tower) are totally dead with a red light. It will green light every time at the start but then shut off. This happens on both towers.

Fixing Attempts:

My first instinct was to recap the entire amp board and even the tweeter board for good measure; these are 25-year-old caps, so maybe they were dying. No dice, still fails after 30 minutes. I triple-checked all the positive/negative directions. They are the correct cap types as well. Cap job was fine, even on the tweeter board (brown board in the pictures).

I thought it was overheating after this. I tried blowing a ton of air directly on the board with a fan (had the board partially out with the screws loosened so air could flow across the board and the caps). That did not work; same problem. I also tried crimping new wire and attaching it to the speaker drivers themselves with a more secure connection, thinking maybe heat was causing some kind of problem with the fit. Still has that 30-minute timeout period, no matter what I do.

I did some measuring with a multimeter, but I can't make heads or tails of much. If anyone can tell me the continuity checks I need. I can provide more pics of the chips if need be.

I checked on the 4 MOSFETs, and apparently they come out with a good reading.

I also replaced the IR2111, which are chips that are not soldered in. Still no changes.

Where I am now:

Really like the speakers when they work, but god damn, buying new amp boards, if that is even possible since these have 3 wires, some kind of extra connector (2-pin top right) is going to cost a ton with money I do not have right now. I blew close to 100 bucks on parts (some I didn't even need) trying to fix this thing. Still has the same problem. Works for 30 minutes, green light turns red, subwoofers stop moving.

AVR is a Denon x4700h. Powers my Klipsch passive speakers just fine.

Just found this in a relative's garage, disk drive 1 and 4 work great, but 2,3, and 5 won't read the disk. Checked out the user manual and troubleshooting steps and didn't find anything helpful! Any ideas would be great!

https://www.manualslib.com/manual/151981/Sharp-Cd-Es777.html

Hello. I purchased an RPW-10 at an estate sale. I wasn't able to test prior to bringing it home. I plugged it in and ....nothing. I checked the fuse and it was blown. I opened the back panel of the amplifier plate and this is what I see.

I've read about the conductive glue causing problems in these Klipsch amps. (Is this glue or a leaked cap?)

I've built a guitar tube amp and I've soldered plenty of guitar pedal boards. I almost feel like I could repair this but is it even worth trying to desolder the vertical daughter board and cleaning it up, replacing whatever is burnt?

Am I better off buying a new sub amp plate off Dayton audio/Amazon? Could I just run one of those class D monoamp boards into the sub?

Btw, I contacted the estate sale and they refunded me and said I could keep the sub. So if I break it, it's no big deal.

I’m planning on refoaming the woofers on these old speakers (for obvious reasons lol) but i can’t figure out how to get the driver out of the enclosure. None of those screws on the front are actually real as far as i can tell, pretty sure they’re plastic and they crack when i try to turn them with an alan key. No access from the back either, you can kinda see the spots where 4 screws poke through the back (circled). Idk if that helps because I can’t find a way to do anything with those screws lol. Only other option i can think of is to completely disassemble the enclosure but I really don’t wanna do that. Too broke for new speakers so any help would be appreciated, sorry for the big paragraph haha

WM-F03. Plugged the rechargeable battery into a 1.5V adapter connected to a 9V battery supply (incredibly dumb mistake, I know). The corner of the circuit board is now burnt and there’s a liquid emanating from the board. Now no sound comes through when I use the tape player, not even white noise. The power light still comes on, the mechanical bits all still work (play, stop, ff, rw, auto reverse) and the radio still has sound coming through it. As you could guess I’m very inexperienced with electronics and haven’t the skill or equipment to fix this myself, so I wanted to know what my options are in terms of fixing this, as I don’t have the money to replace it currently.

Hello there is no sound coming out of this marantz. Obviously to me it looks like the relay needs replaced. Do these two things need to be replaced while I am at the relay since it looks like they have leaked. How do I know what to order to replace these? I don’t have much history. I bought it for parts on eBay probably 12 years ago but with the rust there may have been some water damage?

This is where the headshell connects to the tonearm on .y marantz 6100. I am trying to figure out why i have no left channel. From everything I've read, the contacts should be spring loaded, but these don't seem to be moving at all. I've tried spraying some contact cleaner in there, but I'm not getting any spring action. Is this a part that can be replaced?

Hi Folks!

Just wanting to confirm my troubleshooting narrowing it down to the left power amp:

1. noise doesn't change when using volume knob

2. doesn't change when stereo/mono knob is changed

Measured the voltage between the left A outputs with the multimeter... volts fluctuate somewhat wildly (from a range of .3 to like 1.8) when noise occurs, and dissipates when not noisy.

I'm seeing that I should replace the 2SA798 transistor with a matched pair of KSA992s. Is that the first thing to do or is there something else more obvious? Anything else I should replace while the board is out?

Somewhat new to this, but eager to learn more.