Re: M-audio AV30 speakers recap and repair

I finally got back to this project. I plugged the Vin and Vout from the regulators into the vacant holes where the (removed) 2W resistors had been and drilled a couple other holes on a nearby beefy area of the ground plane. I put the regulators (insulated) on a single oversized heatsink that snugly tucks into a gap between the transformer and the heatsink for the output transistors and after double-checking things, and crossing my fingers, I fired it up. Am reading almost 34Vac across the transformer, making me wonder how the zeners ever...

Re: M-audio AV30 speakers recap and repair

I haven't decided upon any solid course of action yet, I'm still brainstorming.
The panel is metal and grounded, I might have tack-soldered the heatsinks on, had both devices had ground on the mounting tab. Epoxy is an option. I could leave a "live" heatsink inside the speaker, it's not like -14v or -20v at 1A is going to curl the hair of someone shocked by it (I'll probably be the last person inside this speaker). But, that doesn't seem a clean solution. I'm tempted to search for a couple insulators with decent thermal...

Re: M-audio AV30 speakers recap and repair

Thank you, everyone, for all the useful information.
I am in the US and our utility provides a consistent 118vac @ 60hz.
A tall pair of 18mm nichicon VZ caps rated at 3300uf/50v/105c fit nicely as replacements for the primary filter caps. The higher voltage was probably unnecessary, but I replaced the caps on the output side that had literally melted down with nichicon PJ's at 220uf/35v/105c (was a snug fit).

I looked in my junk box and found I had salvaged a pair of these heatsinks off of some dead critter:...

Re: M-audio AV30 speakers recap and repair

I bought a dead pair of these for $5 at a Goodwill last week.
I cracked mine open and found a Rev 2.0 board where C47 and C48 are domed on top, have blown the plugs out the bottom, burned off their labels, vaporized any through-the-hole plating, and left a charred pit on the bottom of the PCB. One zener diode (which tests open in both directions) and the run around it is as toasted as were the caps. The second zener tests good but also shows signs of abuse.
There's plenty of real estate to scrape off some green lacquer and...

Re: vixio vx42l hdtv10a

Wow...
One usually assumes the bad part you pull out will be the same value as what you'll put back in... My VZ42HL main supply board doesn't look like the pictures you all are posting here. Could someone please tell me the value of C241? It's one of the caps under the heat sink on the right side of the supply. It's the cap closest to the center white connector. I have a bulging Nichicon 470mfd 100v 85c in that hole and a solder flux mess around it's PCB connections.

It think someone substituted their own value...
Is C241 supposed...

Re: vixio vx42l hdtv10a

I just had a Nov 2007 VX42L sent my way. All four 470uf 35v caps on the inverted boards are toast, and they show signs of having been replaced before. I believe I have some Panasonic FM's around I'll use, but I wonder if someone might help me determine what the last tech considered valid replacements... the last repairperson installed Samwha LT series. They are stamped 105c, but I can't for the life of me find any specs on the LT series on the web?
Thank you.

PS - There is also some bulging on the largest filter on the main supply, a...

Re: VX922 with FSP035-1PI01 PSU

I have a VX710 flat panel with the exact same power supply.
It will power on for approximately a second then go black. The power indicator stays on green and steady, and correctly switches to amber if the input signal is lost.
While on, the screen looks fine, you can repeatedly display the screen for a (short) second by toggling the power, or holding menu button "2".

So, I popped it apart expecting to find barfing caps, but none appear faulty. Although there are a couple of the notorious Capxon's.
Closer...

Re: Rubycon bad cap series..

Hah! I'm back from last January and still whining about my dying SX270 SFF PC's. I'd begged a batch of mobo's out of Dell prior to their January bad-cap-replacement cutoff and am just now running out of spares. kc8, you'd mentioned you were going to try a polymer fix, I'm off to read the thread you referenced!!!

PS - Seeing just one or two erupted MCZ's in these Vesuvius motherboards is the exception for me, the attached photo I put in this January thread shows *15* toasted Ruby MCZ's: [URL=https://www.badcaps.net/forum/showthread.php?t=4793&page=3&pp=20]https://www.badcaps.net/forum/showthread.php?t=4793&page=3&pp=20[/URL]...

I'd had a discussion here about this back in January with no resolution...
I pulled another board yesterday with another batch of ugly Rubycon MCZ's (only 9 of them erupted this time). My stack of refurbed Dell GX270 SFF Foxconn/Vesuvius/Killerbee motherboards is now down to one.

I somewhat came to the conclusion from the previous discussion that these tiny SFF PC's are thermally challenged. There was talk by some of trying polymers in the GX270. Has anyone tried such a mod? Does anyone have a good inexpensive source for compatible solid caps in small quantities? (It doesn't...

Re: Unknown Cap on D845HV Board

[url]http://capacitor.web.fc2.com/[/url]

(I like the brand called "Vent")Re: Unknown Cap on D845HV Board<br /...called "Vent")Re: Unknown Cap on D845HV Board

[url]http://capacitor.web.fc2.com/[/url]

(I like the brand called "Vent")

Re: When to Choose ZL vs. MCZ

Yes, the stripes are all lined up like good little soldiers, no polarity issues here. The PC actually ran anywhere from 1 to 15 minutes before freezing with the board with the 15 leaking MCZ's. The PSU ran fine for a day with the new motherboard before I swapped it to give it a visual inspection, which it passes. The CPU is up and running for 2-3 days now without a glitch. The air exhausting out the back is MUCH cooler now, having functioning capacitors.

I was leaning towards it being a thermal issue causing the MCZ's to fail. Is it feasable...

Re: When to Choose ZL vs. MCZ

We have 13 (lucky, huh?) of the GX270 SFF's here. They all run 24/7. They are placed in fairly well ventilated areas but use only the (inadequate) stock cooling. Both DIMM slots are populated (512 * 2), but AGP and PCI slots are unused. The processors vary from 2.66 to 3.2mhz with a mix of Northwood and Prescott cores. The processors are likely taxed somewhat most of the time as, having no true video card, they do all the work in displaying Serenescreen's Marine Aquarium 2 (hi-res) screensaver most of the day (the patients love it). The actual applications...

Re: When to Choose ZL vs. MCZ

Dell's free ride on replacing GX270 motherboards ends this month, so, planning for the future, I'm starting to shop caps or cap kits for manual replacement.

I had already crossed Rubycon MCZ's off my list, yet find they are touted as reliable here. The following photo is a late-model (Rev A02) GX270 mobo with 15 caps that have barfed all over (the 2 that look decent puked the electrolyte out the bottom). The entire batch (as shown by inset in lower-right corner) are Rubycon MCZ's. So... what gives? MCZ's are good? or garbage? Or do you...