What do I need??

[stevo1210]

Hello Everyone,

Today I got an old pair of speakers from a friend of mine. . I think the speakers belonged to some old HI-FI unit but they look decently new and in a moderate condition.
Anyway, I took them home and I went looking around my shed and found the stereo from our old GM/ Holden Commodore VN.
The stereo was removed a long time ago and has been sitting dormant in the shed for the past 10 years.
I had a look inside and all the caps are either Nichicon or Panasonic and they are all in good condition, considering that the unit is at least 17 years old.

I want to hook this stereo up to the pair of speakers I got. So far I have a 12V power adaptor for power to the radio.
Only problem that I am facing now is that I don't know any of the pinouts of the stereo unit, so I can't power it up.

I don't know what to do to find the pinouts. What can I do to find these pinouts? And am I missing anything else that I may need to make this stereo work?.

The model of the stereo is a Eurovox MCC-6615V. I will post pictures soon.

Thanks.

[kikkoman]

Re: What do I need??

try this (in case your unit has cables and not only a plain connector):

http://www.justcommodores.com.au/temp/wiring.htm

[kikkoman]

Re: What do I need??

rrrrah! the edit limitation sucks!

http://www.eurovox.com.au/html/download.htm

[Krankshaft]

Re: What do I need??

Heres another:

http://forums.justcommodores.com.au/...g-colours.html

[stevo1210]

Re: What do I need??

Thanks guys!!. That's just what I needed.

I also have a question.... how many amperes should my 12V be to power my radio cassette unit??

Thanks.

[Krankshaft]

Re: What do I need??

Thats anyones guess I'd say try something in the neighborhood of at least 5 amps a computer power supply would do nicely if you have some lying around. Just make sure that its 12 volt rail is at least 5 amps.

If you hear the supplies fan bog down when you turn the radio on then you don't have enough amperage.

Remember current unlike voltage is drawn by the device you are powering so it doesn't hurt to go above the devices current draw.

As a matter of fact going above the devices maximum current allows the supply to run cooler and last longer then a supply that is constantly being driven to its limits.

Just tap off of the yellow wire on the supply (12 volt rail) and the black wire is ground.

To start up the supply just short the green wire on the ATX harness to ground.

Some supplies (not all) require a load to start up. If you jumper the green wire to ground without anything connected to it and the fan doesn't come on then this is a giveway.

These load detecting supplies I'm familiar with only look for a load on the 12 volt rail in order to start however there may be supplies that look for something on the 5 volt rail or both as well.

A good "dummy load" if the PSU won't start up is an old hard drive.

[hardwareguy]

Re: What do I need??

Most of these old radios will start with about 1.5A....but you won't be able to get more than a watt or two at that current. It will still work to see if it still works though. The voltage will collapse on the PSU if you overload it, the warning sign of this is of course clipped audio.

[starfury1]

Re: What do I need??

The radio would use power audio amp IC(s)
and as above you would need a PSU with a bit of beef (current)
(other words a 12 volt DC wall wart is "not" the psu for the job)

See if you can get you hands on an old CB power supply, preferably a better quality/current unit.
These are a linear supply (not a switcher, well old ones)

There were a lot of 2.5 Amps jobs some 4A but bigger then that you would be paying big money for so not many had them unless they were running after burners.(or a couple of rigs)
But you maybe lucky and find a beefy one.

I say this cause I am guessing you don't want to spent money or much money anyway.

They will be rated a 13.8 Volt whatever Amps.
(normally will have a continuously and a peak rating, just watch out for the ones that say 4A and are really 2.5's)

I don't know the radio in question but
If you not going to use it like a mobile BOOM BOX on wheels
(in other words just listen to it quietly at normal levels)
You probably get away with a 2.5A ~ 3A type

Chances are it doesn't have much wattage anyway and will sound like crap when pushed hard regardless.

Look for big heavy transformer inside, feel the weight of it.

so check out trash and treasure places and maybe the old pawn shop
(although I find they over charge for everything).

PSU's like this are handy to have around regardless.

The price of building or buying a psu for this...its way better to go dumpster diving ETC for one

HTH

Cheers

[stevo1210]

Re: What do I need??

Will an old Deer PSU be able to power this old radio?? It's the only spare PSU that I have that will power anything close to 5A.
I was also wondering... do speakers have a voltage rating?? I only see an impedance/ ohms rating and that's it. Sometimes there's a wattage rating also, but never a voltage rating.

Thanks.

[kc8adu]

Re: What do I need??

Will an old Deer PSU be able to power this old radio?? It's the only spare PSU that I have that will power anything close to 5A.
I was also wondering... do speakers have a voltage rating?? I only see an impedance/ ohms rating and that's it. Sometimes there's a wattage rating also, but never a voltage rating.

Thanks.

deer?
you havnt tossed that pos?

[stevo1210]

Re: What do I need??

deer?
you havnt tossed that pos?

Not yet. I even went through the trouble of recapping it earlier this year.
It used to power my server but I replaced the Deer with a Delta PSU.

[Krankshaft]

Re: What do I need??

That supply should be fine for testing purposes.

[stevo1210]

Re: What do I need??

I got the radio to turn on a few days ago. I can inserte a cassette tape and see the motors spin in action, but I have a big problem, and that is I can't see anything on the LCD display on the front.
There is backlight to the LCD and buttons, but no text on the LCD display. IMO, I think it might be a broken solder joint since the LCD metal pins are soldered directly to the PCB. What else could be wrong?

Thanks.

[stevo1210]

Re: What do I need??

I have some images of the radio cassette unit I am talking about. I removed the fron bezel/ cover so in the images you can see that the unit is on but there is no LCD display although the back light is on.
The PSU being used to test this radio cassette unit is a Delta Electronics 250W P4 ATX PSU, so I don't think power is a problem.
Can anyone please help me find out why the LCD isn't displaying anything??.
I know that the LCD worked before storage.

Thanks.

[Spyke]

Re: What do I need??

"Always On" positive terminal connected?

[stevo1210]

Re: What do I need??

"Always On" positive terminal connected?

Is the "always on" terminal the permanent terminal? I haven't connected any wires to the permanent. I thought the permanent wire was to allow the radio to remember the presets??.

If I need to connect the "always on" cable... what voltage whould it be? 12V?

I still remember that a long time ago, another car radio had the permanent wire disconnected and everytime the car was started up again, the radio would lose the time and presets, but the LCD still worked though.

Thanks.

[Spyke]

Re: What do I need??

Yeah, its 12V, same thing as the "On" voltage.

A lot of models power the low power electronics section with the "Always On" voltage. This almost always includes the display controller as well.

[hardwareguy]

Re: What do I need??

Like others said, some radios need both the B+ and Memory lines connected.

B+ powers the amp, tuner and tape on every radio but some use the Memory line for not just the clock but the MCU/display as well. In these, the clock is likely part of the MCU/dispay controller.

Judging by the circuitry, 1.5A should be enough to see if it still works (a small amount of output will be available) and 5A will be needed for full output.

[PCBONEZ]

Re: What do I need??

For the current look up the fuse size in a manual for that old Holden.
(Try the library for that.)
.

[intp1000]

Re: What do I need??

No voltage rating needed. The ohms and wattage will give you the max. V. V=(WR)½. Radio speakers were usually 3.2 to 6 ohms. Just supply the current needed (volumn) and the thing will work. Speakers are current driven devices. You could, in theory, supply 1KV, current limited of course, and the speaker would be find (except for flash over).