Fet Valve 500 Amp (Older Version) Power Button Light Not Lighting Up

TjMV3 · « **Reply #20 on:** 21 Sep 2008, 05:18 pm »

Okay, I'm going to try replacing this Buss MDA 10 fuse.

Question....

Are there different Buss MDA 10 fuses with different specs and values?

Or are all Buss MDA 10 fuses the same specs/value?

Should I just ask for a " Buss MDA 10" ceramic fuse? Or do I need any other spec/value information?

http://www.overniteelectricsupply.com/mall/morea.asp?ProdID=20284

JerryM · « **Reply #21 on:** 21 Sep 2008, 05:21 pm »

That is a slow blow fuse. It should be available at any Radio Shack or auto part store. Installing a new one is the best test.
Wishing you luck,

Jerry

TjMV3 · « **Reply #22 on:** 21 Sep 2008, 05:23 pm »

Quote from: JerryM on 21 Sep 2008, 05:21 pm

That is a slow blow fuse. It should be available at any Radio Shack or auto part store. Installing a new one is the best test.
Wishing you luck,
Jerry

Ain't that truth!!

We'll, I'll head out in a little while.

Thanks so much guys!!!

TjMV3 · « **Reply #23 on:** 21 Sep 2008, 05:47 pm »

Well, I called before going out and the guy at Radio Shack claims I need to know the value/spec information.

He says he can't cross-reference by just " Buss MDA 10".

So, anyone know the value/specs on this thing?

I'm guessing the " 10 " indicates it's a "10 amp" fuse.

Anthing else? Anyone...anyone...Bueller?

JerryM · « **Reply #24 on:** 21 Sep 2008, 06:01 pm »

Hmmm... Based on the information you posted it is a 10 amp, 250 volt, AC slow blow fuse. I can't imagine needing more information than that. I mean, a Buss MDA10 is a Buss MDA10. There is no cross reference.
Try an auto parts store. You may find someone that knows this fact.
How did tightening the RCA jacks go?
Have fun,
Jerry

TomW16 · « **Reply #25 on:** 21 Sep 2008, 06:03 pm »

Google helped me with the following:

http://www.relectric.com/Store/Fuses/MDA-10

The details are as follows:

Product Details
Item Name: MDA-10

Manufacturer: Bussmann

Characteristic: Time delay

Type: Ceramic tube

Votage Rating: 250 ac/dc

Current Rating: 10 amp

Description:
Time delay Characteristic, Ceramic tube Type, 250 ac/dc Votage Rating, 10 amp Current Rating, Fuses Fuses from Bussmann

Cheers,
Tom

TjMV3 · « **Reply #26 on:** 21 Sep 2008, 06:23 pm »

Quote from: JerryM on 21 Sep 2008, 06:01 pm

Hmmm... Based on the information you posted it is a 10 amp, 250 volt, AC slow blow fuse. I can't imagine needing more information than that. I mean, a Buss MDA10 is a Buss MDA10. There is no cross reference.
Try an auto parts store. You may find someone that knows this fact.
How did tightening the RCA jacks go?
Have fun,
Jerry

So far tightening the RCA jack inputs has been difficult. It's a very tight spot and with and angle. There's a a square circuit board with four large caps sitting right in fornt of the path to the jacks. So I'm trying to find wrench or ratchet that can get back there and not put pressure on the Caps or damage them.

Tom, thanks for those specs.

I saw that earlier when I did a google search, but I wasn't sure if those were the correct specs I needed for this amp and fuse.

Product Details
Item Name: MDA-10

Manufacturer: Bussmann

Characteristic: Time delay

Type: Ceramic tube

Votage Rating: 250 ac/dc

Current Rating: 10 amp

Description:
Time delay Characteristic, Ceramic tube Type, 250 ac/dc Votage Rating, 10 amp Current Rating, Fuses Fuses from Bussmann

mark funk · « **Reply #27 on:** 21 Sep 2008, 06:28 pm »

I know a good way to make sure. Take the fuse out and look at it, it should say what it is on it. And use your fingers not a butter knife to remove the fuse.

TjMV3 · « **Reply #28 on:** 21 Sep 2008, 06:55 pm »

Quote from: mark funk on 21 Sep 2008, 06:28 pm

I know a good way to make sure. Take the fuse out and look at it, it should say what it is on it. And use your fingers not a butter knife to remove the fuse.

The first thing I did was read the fuse. But all it has etched on there is "Buss MDA 10"

That's it.

I wouldn't have had to ask it had the specs/values right on the fuse

TjMV3 · « **Reply #29 on:** 21 Sep 2008, 09:19 pm »

New fuse has been installed.

getting it back in the rack.....in a few minutes.

TjMV3 · « **Reply #30 on:** 21 Sep 2008, 10:07 pm »

Well, that didn't work

Ne w fuse was installed......

Still no power and still no power indicator light.

I guess I'll have to talk to Frank and see what he suggests, tomorrow.

JerryM · « **Reply #31 on:** 21 Sep 2008, 10:16 pm »

Darn, that sucks.

Sorry the idea didn't help. I thought for sure it was just that fuse. Frank will certainly save the day.

Play whatever tunes you can, have a beer, and know you gave it a good shot.

Come to think of it, a good shot wouldn't hurt right now, either!

Good luck,
Jerry

Tom Alverson · « **Reply #32 on:** 21 Sep 2008, 10:26 pm »

It is possible that the new fuse just blew due to a problem with the amp. Or it could just be the power switch is not turning 'on'. I would take both fuses to Radio Shack and see if they will measure them for you with one of their many digital volt meters. If both fuses are good, then the problem is most likely just the power switch. If you know someone who is handy with a soldering iron, you could have them jumper out the switch so the amp is always on and connect it to a switchable power strip.

Tom

avahifi · « **Reply #33 on:** 21 Sep 2008, 10:49 pm »

Sorry I did not get to this thread sooner. I actually took most of the day off for once.

You need an ohmmeter (Digital Multimeter) to measure the main power supply ceramic fuse. You can get an inexpensive one at Radio Shack. Set it on ohms and measure across the fuse (out of circuit of course and with the amp unplugged from the AC wall outlet). If the fuse is good, the reading will be near zero. If the fuse is open (blown) then it will measure very high resistance. If two fuses have blown in a row we will need to see the amp for service. Possibly something went wrong in shipping. If the fuse measures good and no other fuses are blown and the power switch internal lamp is not lighting up, then I would be suspect of the power switch. Call me at 651-330-9871 for more help. Note that a replacement main power supply fuse, the one all by itself and with a white body must be replaced by another slow blow type fuse. A standard fast blow fuse will fail immediately from the turn on surge current. All other fuses should be fast blow types (6 amp internal and 4 amp external 3AG series fuses). A ceramic type was required for the main supply fuse to get the proper voltage rating, along with the proper current rating (10 amp).

Frank Van Alstine

TjMV3 · « **Reply #34 on:** 22 Sep 2008, 03:34 pm »

The Travesty Of Errors.............

Well, as it turns out the guy at Radio Shack did in fact give me the Fast Blow/Fast Acting 10 Amp 250V fuses. Let's ignore the fact that I repeated the words "Slow Blow" roughly 12 times in my request for specs/values of the fuse I needed. Did I mention "Slow Blow"?

Ulitimately it was my fault because I was distracted by my two year old son who wanted to toddler-handle the display items at Radio Shack. So I didn't stop to read the bag of fuses he handed me. Just paid and left. I didn't even read the bag when I got home. Just cut open the top of the bag and took one of the fuses to the amp. That's what I get for assuming the guy at Radio Shack was listening and for my not being dilligent and double-checking.

So today I have been on the phone for over an hour and a half calling every place I can think of ........for a 10 amp, 250V Cermaic Slow Blow fuse. Did I mention I need a " Slow Blow" ?

Anyway, it appears the only options available are internet sales for these fuses.

Matthew of Van Alstine was kind enough to offer the mailing of this fuse, to me; so I can determine whether it was the fuse, or not. Thank you Matthew. And I'll buy some for back up, from internet retailers.

BTW, I called Auto stores, Lowes, Musical Intrument sales and repair stores/shops, TV repair shops, all three Radio Shacks in my general area and a Tube amp repair (amps for guitars and etc) guy in my area. None of them had this fuse.

Apparently this tube is quite rare and difficult to find.

Thank you to everyone for offering their opinins and help!!!

I'll follow up when the fuse arrives.

Wayner · « **Reply #35 on:** 22 Sep 2008, 04:11 pm »

I lost a slo-blo fuse in my U70 and found one at Ace Hardware. It wasn't a 10 amp as I recall, but they may have one. The store we have in town has a nice assortment.

I have observed that Rat Shack doesn't always have "electrical" type people working there, just someone that knows how to run the register and lock up at night.

Wayner

Wayner · « **Reply #36 on:** 22 Sep 2008, 04:19 pm »

http://www.galco.com/scripts/cgiip.exe/wa/wcat/itemdtl.htm?pnum=MDA-10-BUSS

stereocilia · « **Reply #37 on:** 22 Sep 2008, 04:33 pm »

It wasn't completely clear from the thread so far, but I assume you made sure the outlet to which the amp is plugged in is working. (Yes, I've made this mistake).

BTW I'm fortunate to live near an alternative to Radio Shack. Unfortunately, your experience doesn't surprise me. Best of luck!

dB Cooper · « **Reply #38 on:** 22 Sep 2008, 05:02 pm »

Quote from: Wayner on 22 Sep 2008, 04:11 pm

I have observed that Rat Shack doesn't always have "electrical" type people working there, just someone that knows how to run the register and lock up at night.

Wayner

I worked at RS awhile and I can tell you that all they care about anymore is pimping cell phones. Sorry about the off-topicness.

avahifi · « **Reply #39 on:** 22 Sep 2008, 05:06 pm »

First of all, please use a ohmmeter and find out if the fuse in the amplifier is open or not! If it is good, there is no point sending another fuse.

Regards,

Frank

Your local Radio Shack or any TV repair shop can check this for you. All you need to do is take them the fuse.