Amp Jewel Light Gorn Bad

Bellycaster

Whoopie! My next lesson in Amp Maintenance.

Just as we were about to pack up last, my Maz Jr. 18 Amp light decided it would also pack up. I thought one of the guys had pulled out a plug, but not to be, the Guitar sound was still coming out of the speaker.

So, is this an isolated problem? Does it begin and end with the light? As in, not a by product of another problem with the amp. I'll recheck the amp is fine again later today.

Can you guys tell me how I change it and where to buy the bulb, how I will know I've got the right spec! Does it need to come from Dr Z? Can I get one from any Electrical store or the store I bought the Amp from?

I'm really surprised that the bulb has gone, I thought they lasted ages, the amp is only 20 months old.

Thanks.

merlin

Either
a) unscrew the jewel, remove the bulb and see what it says. Buy whatever it's called or same spec and replace using the above instruction in reverse.
b) look online or in the manual to see what bulb it is, unscrew the jewel, remove the bulb and replace using the above instruction in reverse. 

It may be a lot cheaper to buy the new bulb from Halfords or Maplins (except that they don't exist anymore, so equivalent electrical store online) than from a guitar shop. 

It's happened to me on a few amps, they seem to work fine for as long as it takes to replace the bulb. Someone chip in if I'm talking shit please....

ICBM

I thought it was only valves that Dr.Z's killed at a stupidly high rate...

It's very common for the bulb to fail. It's a standard 6V bulb running from the valve heater filament supply usually.

First check it isn't just making a bad contact with the holder - they often do. If it's a standard jewel light the front part will unscrew. It's a bayonet fitting so if you want to take the bulb out, push in slightly and turn - this can be a bit tricky.

If it is dead, replace it with a 12V car dashboard/sidelamp bulb from any car parts shop and it will (probably) never fail again.

Bellycaster

Thanks chaps, will get on it tomorrow. Seems these amps do wear things out quick @ICBM especially the operator

Dominic

just the same as changing a domestic lightbulb ....screw or bayonet 

ecc83

These bulbs can be the very divil to remove, 50mm of suitable rubber tube (not plastic) is useful.

N.B. If anyone has a bulb fail on any early B'star Artisan you WON'T get the lens off! The overzealous peeps in Korea put the green T'lock ***t on both back AND front threads!  Very careful heating with a hair dryer and  wear a Marigold for extra purchase.

Re the 12V car lamp idea IC? In the radio trade, 'Panel Lamps' were always specified as '6to 8V' and needed changing less often than once a decade.

Dave.

Bellycaster

It's a Bayonet Fitting and the bulb is Type T47 according to the Manual. On the bulb itself it says AML-47. I've googled these and they are available from Hot Rox and G4M but surely I should be able to get these from a store somewhere like B&Q or Wickes......No? I was gonna say Maplins, but then remembered.

ICBM

Bellycaster said:

It's a Bayonet Fitting and the bulb is Type T47 according to the Manual. On the bulb itself it says AML-47. I've googled these and they are available from Hot Rox and G4M but surely I should be able to get these from a store somewhere like B&Q or Wickes......No? I was gonna say Maplins, but then remembered.

https://www.ebay.co.uk/itm/RW233-Bulb-12v-4w-T4-MCC-BA9s-Side-Tail-Interior-Dashlight-number-palte-Bulb/172537587503?hash=item282c0aa72f:g:l54AAOSwr~lYqDIl

Bellycaster

ICBM said:

Bellycaster said:

It's a Bayonet Fitting and the bulb is Type T47 according to the Manual. On the bulb itself it says AML-47. I've googled these and they are available from Hot Rox and G4M but surely I should be able to get these from a store somewhere like B&Q or Wickes......No? I was gonna say Maplins, but then remembered.

https://www.ebay.co.uk/itm/RW233-Bulb-12v-4w-T4-MCC-BA9s-Side-Tail-Interior-Dashlight-number-palte-Bulb/172537587503?hash=item282c0aa72f:g:l54AAOSwr~lYqDIl

Ahh, thanks @ICBM I didn't realise there was such a thing as free delivery, especially on a cheap item

robgilmo

Wont a 12v bulb burn dimmer?

ICBM

robgilmo said:

Wont a 12v bulb burn dimmer?

Yes, but not much. Still easily bright enough.

Bellycaster

Those bulbs were fine @ICBM thanks, it doesn't seem to be noticeably dimmer. I assume the difference in voltage makes no other difference to the amp?

ICBM

Bellycaster said:

Those bulbs were fine @ICBM thanks, it doesn't seem to be noticeably dimmer. I assume the difference in voltage makes no other difference to the amp?

Not that you'd notice - it runs the PT about 1% cooler probably .

Bellycaster

ICBM said:

Bellycaster said:

Those bulbs were fine @ICBM thanks, it doesn't seem to be noticeably dimmer. I assume the difference in voltage makes no other difference to the amp?

Not that you'd notice - it runs the PT about 1% cooler probably .

No problem, thanks. I did buy 2 bulbs as well, cos it seems these amps consume things a little quicker than most

Kebabkid

Glad it's all sorted Jon