New bulbs for Carver TFM-55 (works great then buzzz....poof!)

gwg_97

Well I got the new meter bulbs for my new to me TFM-55. See the smaller clear ones and blue ones in the photo (next to the old larger clear bulbs). I soldered them in place and fired it up. All is well, the lights work on both the normal and dimmer setting. Cool! That was easy! I'm feeling pretty smart!

OK, I wasn't satisfied with the light's compromised (broken) pin connection to the pcb (it was that way when I opened up the amp), so I added some heat and pushed what was left of the broken pins out of the pcb a bit, then I added a bit more solder. Reconnected the wires to the pcb with the existing "pin connector" and fired it up again. I got that familiar buzz at start up (What! No lights!), I waited for the usual click (at 4 seconds) and instead I got a prolonged buzz, then "pop" with a bit of smoke from the right rear of the amp. Crap! Is that the dreaded "Carver smoke"?

Luckily both channels still work and the amp sounds fine. The meters also work except for no lights.

So much for my inexpensive new amp. I really don't want to spend $300 to get this guy fixed. Any ideas. From what I can see, nothing appears to be cooked in the amp. Weird!

disneyjoe7

I would go over your work again too see if anything is ok. I'm a bit worried about "OK, I wasn't satisfied with the light's compromised (broken) pin connection to the pcb (it was that way when I opened up the amp), so I added some heat and pushed what was left of the broken pins out of the pcb a bit, then I added a bit more solder"

gwg_97

Yeah, me too. Something definitely cooked. Here is a photo of the potential smoke area (see R218 at the center right of the photo and R208 at the upper center of the photo). I should note that the R218 area had a bit of white residue and black stain around it before I even touched the lights. Not sure about the area near R208.

Glowrdr

Is that where you added some solder? It almost appears to me that R218 and Rx02 are connected

gwg_97

The only place I added solder was on the light's pcb (inside the yellow circles). The leads on the other light are outside of the photo to the right. The orange and white wires in the photo were previously to attach to pins/wires on the pcb via a connector. That was broken when I opened up the amp. I simply cut off the old connector and soldered the wires directly to the pcb

Glowrdr

Aaah - must just be the picture then. Should be an easy fix, less than $100 if I had to guess.

gwg_97

I called Rolland today. He is 10 weeks out. Bummer!

disneyjoe7

I bringing to think the new bulbs draw more current, and blow some circuits. Just a thought...

pitdogg2

gwg_97 wrote: »

I called Rolland today. He is 10 weeks out. Bummer!

Trust me his wait is worth waiting for.

gwg_97

Yeah, that is what I figured. Not a big deal. Thanks for the heads up!

pitdogg2

disneyjoe7 wrote: »

I bringing to think the new bulbs draw more current, and blow some circuits. Just a thought...

hows that happen? It's only going to get the current sent to it...right? If i remember right something like 6 volts is all that is sent to them.

gwg_97

pitdogg2 wrote: »

hows that happen? It's only going to get the current sent to it...right? If i remember right something like 6 volts is all that is sent to them.

Yeah, I think its only 6v per lamp (12v total). I'm begining to wonder if the bulb change and the smoke were unrelated. Previous to changing the bulbs, I only fired the amp up a couple of times and it buzzed pretty loudly. I'm pretty sure that amp was sitting for years untouched before I bought it. Stranger things have happened.

ambiophonics

Voltage and Current are not the same - the bulbs would draw whatever current they require - that's not to say the power supply can provide that amount of current. That being said, I bet that these are separate issues.

disneyjoe7

Thinking those resistors and or transistor is fried do to Current being drawn by the new bulbs.

Drenis

Not sure where your nearest place is you can send your amp too.

You could try Rob Galayda here in Winnipeg (http://musicalintegrity.com/). Carver's are his "thing" and it's where my serviced unit came from. It's also half the distance to Rolland's.

vijayl

Is it fixed now. I'm in the exact same situation after replacing the bulb..

mwk455

Can you put the blue lights in all carver amps? The blue ones would match my other lights.

trav0810

mwk455 wrote: »

Can you put the blue lights in all carver amps? The blue ones would match my other lights.

In all of them that I know about! The guys on thecarversite.com are always changing their meter lights or led meters to blue.

EndersShadow

trav0810 wrote: »

In all of them that I know about! The guys on thecarversite.com are always changing their meter lights or led meters to blue.

Yeah I am thinking about keeping it simple and going with white on my M1.0t

trav0810

EndersShadow wrote: »

Yeah I am thinking about keeping it simple and going with white on my M1.0t

Mine go blue...yellow....red. That wasn't a particular need for me, but that's what the guy uses who did my MK2 upgrade. It looks good. But I LOVE the big meters in the M500. If I hadn't already upgraded my M1.0t's I'd rather have a pair of 500's.