Rowe Venus static from left channel

[helterbot]

Hello everyone. I purchased a Rowe Venus last year and it was in good working order when I got it. After having it out in my garage in Minnesota over the winter I'm now having issues with static from the left channel. It seems to come from both the speakers on the top, so I have disconnected them and flipped the mono switch on the amp so I can still use it.

I'm wondering if this is a common issue? I know of an amp in town that I can purchase if mine is faulty, but someone else suggested that it might also be the crossover. I disconnected the CD player and tested it with an MP3 player and got the same results, so I'm thinking the CD player is working correctly. Any input would be appreciated.

Mike

[lilshawn]

 put both leads on the one channel (pink and purple on the left channel connetions) and see if the sound is fixed. if it is, you have a blown transistors on the right side... if it still sounds bad, swap to the left....

if it still sounds bad, you probably have damaged the speakers. likely by water/moisture damage (as they are paper cones)

[helterbot]

I'll give that a try, but I don't think it's the speakers. I forgot to mention that I bought a backup set on eBay and tried all 4 speakers and the sound didn't change at all.

[helterbot]

I ordered a set of transistors off eBay and replaced them today, but I'm not getting any sound with the new parts, but if I put the old ones back it it works as before.  This is the second set I've received as the first one was not giving me any sound either. I also noticed that I had a blown 8A fuse that I replaced as well, but I didn't notice anything after replacing that.

What's the next thing I should try? Is there any way to verify these transistors are good with a multimeter?

[lilshawn]

there is no real way to test the transistors. I have an actual transistor checker made by a test equipment company called "B&K". Known blown transistors will show as good on the tester. I believe it's because of the low voltage used for the test. At low voltages, it tests as good, but at the high voltages and currents in the amp, they fail.

the only real way to "check" them is to use what's known as a curve tracer circuit and an oscilloscope to profile the transistor against a known good unit. it's very time consuming and if you've purchased your transistors from a reputable place, you shouldn't need to.

for future reference, ebay is a REALLY bad place to buy stuff like this, as most... if not ALL the high profile components, are fake counterfeits. Often they are just rebadged general purpose transistors, and not the darlington pair setup used in the original transistors.

[ami-man]

Hi Mike,

It is not a good policy to buy the transistors off of Ebay, there are a lot of bugus one for sale on Ebay in the USA. I know Ron Rich has taken some apart he bought as a trial and they were full of fresh air.

Regards
Alan

Alan Hood
ami-man
UK

[helterbot]

I bought some transistors from a reputable source and the sound is now back to normal. Thanks for helping me out!

[lilshawn]

 

[ami-man]

Hello Helterbot,

I am glad this your issue is resolved.

With regards to jukeboxes there is never a cheap option.
Over the years I have seen some very poor examples of jukeboxes prior to comming into the workshop.
I have seen every botch up job known to jukebox engineers and have repaired all of them, some just take longer that others to sort out.

Regards
Alan

Alan Hood
ami-man
UK