700B blew one Right channel 5A supply fuse

laatsch55 said:
I have a little "Craftsman" (sears) one I got a few years ago for 39.00 In running it against my Fluke 179, not enough difference to count , the frequencies at which we work , that little DMM would work just fine. That analog should be able to measure small DC at the speaker outs, have you tried?
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I agree with Lee that there are inexpensive digital multi-meters available on today's market - but I'm a test oriented kind of guy so most of my stuff retailed at higher prices in their prime. There are some decent used meters on the market on the bay and other venues that you might consider that would run a lot lower than when they were new.
 
laatsch55 said:
I have a little "Craftsman" (sears) one I got a few years ago for 39.00 In running it against my Fluke 179, not enough difference to count , the frequencies at which we work , that little DMM would work just fine. That analog should be able to measure small DC at the speaker outs, have you tried?
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You can get a perfectly decent DMM (for our purposes) with hFE and Capacitance measurement for $30 here in the US.

I own this one (though I have nicer Tenma and Tripplet DMMs also) and it does just fine.
http://www.parts-express.com/digital-multimeter-dmm-with-convenient-tilt-display--390-545

I'm pretty sure I got it as a free gift with $50 purchase over here. They always have this deal going.
http://www.circuitspecialists.com/low-cost-multimeter.html

If you need any other electronics gear, and depending on what freight is like, Circuit specialists could be a real good deal.

All three meters I mentioned measure close enough to be called the same at audio frequencies.
 
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I hope to have obtained some of those AGX 5A fuses later today and will proceed with measuring for DC voltage at the speaker terminals once I have replaced the blown one.

Many thanks for the input on DMM's. There are 3 electronic's parts stores I can visit today in my "Quest for Fuse" and all have an assortment of meters along the lines of those suggested. Based on the price point, they will be of Chinese manufacture and normally I would tend to avoid those, hoping for a good price on a better quality used one. I will revise that thought though and assume that what an old school electronics shop sells would be adequate for my needs.
 
When I did finally find them. I bet they had been there for 30 years. It was at a old local electrical store. Like in the movies when you have to blow all the dust off to see the stuff lol. Trying to fix vintage stereo took me in a vintage store with vintage parts and even a vintage owner. A step back before my time!!! Lmao. I'm stoned as hell this morn so I hope all my rambling makes sence lmao
 
I noticed when you tried to look like a hardass in your pic:-o:bootyshake:
 
I love this place, getting loose around here.....just rught...
 
fitz43 said:
I'm pretty sure I have some if he's unsuccessful in his search. I even have an idea where to find them. Doug
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I was going to give a smart ass narrative about you being a smart ass then i remembered you could be neighbors and you REALLY WERE going to post some pertinent information.....my good....
 
laatsch55 said:
I was going to give a smart ass narrative about you being a smart ass then i remembered you could be neighbors and you REALLY WERE going to post some pertinent information.....my good....
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We could be neighbours. I know where I live. (at #2 today cleaning the mold off everything). Don't know where 62vauxhall lives. My first car was a 69 Vauxhall Viva (not the "epidemic" that was available in Canada) Doug
 
The third shop I went to had some fuses and they too have some very old inventory for sale. Even AC powered 8 track head demagnetizers, brand new in the package.

Did not get AGX 5A fuses but 8AG 5A instead. Same amperage but rated at 250V not 125V like the AGX. Did a quick search before installing and it seemed that AGX 5A and 8AG 5A are interchangeable. The AGX that were in there were BUSS brand, maybe AGX was their designation for glass fuses of that length & diameter?

Turned out both Right channel supply fuses were blown, good thing I got a 5 pack.

1) Put new fuses in
2) Shorted the inputs (I read it doesn't matter if you do this or not).
3) Turned the power switch on
4) Plugged in the amp and panel lights came on.

First checked the Left channel speaker connections for voltage with my analog meter (did not get a DMM today) set at 5V DC. The needle did not budge on Left channel but switching leads to Right channel pinned it. Had to change the meter to 125V DC to get a reading that was not off the scale. What I got was approximately 90V DC.

Neither of the two new fuses blew.

Something bad wrong going on somewhere. Any recommendations on what to do next would be greatly appreciated.

Regarding Vauxhalls. I grew in North Vancouver, BC and there were a lot of English cars around for cheap. Before I had my licence, I got a 1957 Hillman Minx to tinker with and got it running. My dad paid $20 for it and we towed it home with a rope behind his car because the rear brakes were seized. Then, a 1955 Consul for $10 and got that going too. A 62 Vauxhall (Victor station wagon) was the first car I bought with my own money after getting my licence. It cost $150 because it ran and I drove the snot out of it. Blew 1'st gear early on but continued driving it anyway. Just needed a special technique on the hills. Same when the brakes went. Only rear ended someone once. Drove it until I dropped the drive shaft going up a hill, power shifting down from third to second. .
 
You have a shorted semicxinductor on that side of the board. You now have to get a meter that will develope enough forward voltage to test transisrors.....we'll get ya through this...
 
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