Nothing to do with computers

[catgate]

In our car we have a "Sony XR-C450RDS FM/MW/LW Cassette Car Stereo" (so it claim). It does all the clever stuff, like traffic warnings and switching transmitters etc ( when I have reset it correctly after one of us has pushed the wrong button, and all but scuttled it.) It is a problem with grand children living so far away.

It was working well enough but I suddenly realised that the hieroglyphics etc on the indicator panel were no longer illuminated. I asked management if she had any idea when they went off and why. The answer was that when she was last at her fathers (just over a week ago) she had taken the front panel off and taken it with her for the night (we had our last Merc broken into over there just for the radio). On her way home the following morning she noticed it was not lit.

So I had to get out the well thumbed manual, but I could not find an illumination control button mentioned anywhere. Most of the buttons are female, they are heavily into multi tasking, but nevertheless I could find nothing. The set works, and plays the usual load of adverts and stomach churning tripe as well as ever, otherwise it's lack of lumens may have been noticed before.

The manual talks of cleaning the contacts, that convey the amps from the body to the removable panel, with meths and a cotton bud. But this did nothing. This morning I attacked the contacts a little more vigorously with a small portion of 320 grit "wetordry" and I got a very, very small improvement. Some of the numbers were very faintly visible. More cleaning did nothing to improve matters.

Now the odd thing to me is that all the rest of the machine seems to be perfectly happy to do its job but each function seem to be unable to send out a message to its own part of the LCD panel to indicate its state.

Does anyone have any idea about this? All the electrics on the car are OK and my words does it have some.

[AlanHo]

Oh dear - what a bother. I am sure you must have carefully checked that all the contacts are still proud and not stuck in a depressed condition (the contacts - not you).

It would be interesting if you could borrow the front from another Merc to see whether it is your fascia or the stereo body at fault. Would the Merc dealers be cooperative I wonder...?

[catgate]

Oh dear - what a bother. I am sure you must have carefully checked that all the contacts are still proud and not stuck in a depressed condition (the contacts - not you).

It would be interesting if you could borrow the front from another Merc to see whether it is your fascia or the stereo body at fault. Would the Merc dealers be cooperative I wonder...?

One of the contacts looked a little "unproud" and I gently eased it back, though I am sure, from the impression left on the 320 wetaudry, there was no problem in that direction. As for co-operative Merc dealers... they only appear to be co-operative when it comes to relieving you of a walletful of notes.

I am not sure if it is a factory fitted unit because it was in when I bought the car a few years ago.

I had wondered about trying another front, but finding one might be a problem. There is a scrap yard back up towards York but even if they have one in it may be duff, But I suppose it is an avenue to explore.

I had wondered about a Sony dealer, but all dealers, when they see the three pointed star, go into a tremble and their eyesballs roll round like a fruit machine and stop with a row of "££££"s.

[Gandalph]

Have you tried to get any readings from the contacts using an Voltmeter. You should be able to do a circuit test on the fascia and maybe get a Milliamp or Voltage reading from the body with the ignition switched on.

[catgate]

Have you tried to get any readings from the contacts using an Voltmeter. You should be able to do a circuit test on the fascia and maybe get a Milliamp or Voltage reading from the body with the ignition switched on.

i wondered about that, Gandalph, but, in that there are about ten or a dozen connectors, and I do not know where each one goes, nor what sort of reading to expect even if I did know where it went, I did not go too far down that road. Another reason was that I have just thrown my multimeter away due to the fact it would not "multi" it would not even do a single meter. I suspect it may have something to do with its fall being broken by the workshop floor last week. However through the good offices of eBay there should be one heading my way at a high rate of knots as I write.

When it arrives a tentative poke may be in order, providing I can find an earth connection. I am assuming there will be one common earth.

[Gandalph]

Yes, spot on with the Earth, it possibly could be on the back of the body, or even be earthed through one of the mounting screws, it's difficult to say with these modern gizzmo's. You could even try finding the Negative or Return lead and use that to do a circuit test. The readings from the connector pins will be small I imagine, probably somewhere in the region of 20 to 30 Milliamperes of power with around (possibly) 1 to 2 volts. These are based on modern LED displays. I would try and get hold of a Circuit Diagram for it, that might give you all the voltage readings for the set.

Try here. http://cxema.ru/manuals/Sony58_manual.htm Column on right, about half way down.

[artist]

Could it be something simple like a duff bulb?

[-pops-]

artist has a point. Even some of the most sophisticated technology sometimes relies on things as old fashioned as a simple filament bulb. Even if not, and it uses as fluorescent tube/panel, these are prone to failure.

[catgate]

Try here. http://cxema.ru/manuals/Sony58_manual.htm Column on right, about half way down.

Have you ever dealt with them Gandalph? They were flagged red By McAdee site advisor, deal in Dollars or euros and seem to have strong Russian connections. But look as though they have a manual for the XR-C450, but no mention of RDS ( but aren't they all that these days?).

[catgate]

artist has a point. Even some of the most sophisticated technology sometimes relies on things as old fashioned as a simple filament bulb. Even if not, and it uses as fluorescent tube/panel, these are prone to failure.

The display is made up, as required, from a series of what look like seven segment LCD blocks. I thought at first that it had just failed, but since there are faint emanations from some of the blocks, which do change as buttons are pressed, I do not think it has totally expired. The push buttons are mounted on the panel and they all appear to function so to my untutored logic there must be a good earth somewhere.

Maybe the chip in the panel, which controls the numeric display, is duff.

[Irene]

Recently I had an LCD travel clock display go into breakup mode.

My first thought was that the display had died. However, I found that a replacement circular battery solved the problem. Catgate, perhaps yours is a contact problem with the power source.

Just a 'logical' girlie view. Hope it gives food for thought. :D

I just noticed in your first post that you have cleaned the contacts, so maybe you've already addressed this vain of thought.

[catgate]

. Catgate, perhaps yours is a contact problem with the power source.

A reasonable enough thought, but in as much as the front panel also has the control buttons on it, and they seem perfectly happy "to fully display their function" (as the old original Japanese manuals used to put it) I think there is power getting into, and out of, most of the removable front panel.

But thanks for the thought nevertheless,

[Gandalph]

Try here. http://cxema.ru/manuals/Sony58_manual.htm Column on right, about half way down.

Have you ever dealt with them Gandalph? They were flagged red By McAdee site advisor, deal in Dollars or euros and seem to have strong Russian connections. But look as though they have a manual for the XR-C450, but no mention of RDS ( but aren't they all that these days?).

No, never heard of them until I did a Google search catgate.

You could be right in your assumption that the segmented display is on it's way out. Without having the Radio in my hands to do certain tests, it's really just a guessing game. It could be the PLL synthesizer (the Phase Lock Loop controller) or a capacitor on it's way out, a bad earth, and I could sit here all night with speculations and it wouldn't help. It could be something restricting the correct amount of power from getting to the segment causing it be dim. That's why I mentioned the Schematic Diagram being important.

The only other suggestion I can make would be to take it to a qualified auto electrician or electronic repair specialist. HTH.

[catgate]

Try here. http://cxema.ru/manuals/Sony58_manual.htm Column on right, about half way down.

Have you ever dealt with them Gandalph? They were flagged red By McAdee site advisor, deal in Dollars or euros and seem to have strong Russian connections. But look as though they have a manual for the XR-C450, but no mention of RDS ( but aren't they all that these days?).

No, never heard of them until I did a Google search catgate.

You could be right in your assumption that the segmented display is on it's way out. Without having the Radio in my hands to do certain tests, it's really just a guessing game. It could be the PLL synthesizer (the Phase Lock Loop controller) or a capacitor on it's way out, a bad earth, and I could sit here all night with speculations and it wouldn't help. It could be something restricting the correct amount of power from getting to the segment causing it be dim. That's why I mentioned the Schematic Diagram being important.

The only other suggestion I can make would be to take it to a qualified auto electrician or electronic repair specialist. HTH.

Thanks for that, G.

I will see if I can find a service manual somewhere, and failing that it looks like a repair shop.(Or trade in the car !!)

[Irene]

Try here. http://cxema.ru/manuals/Sony58_manual.htm Column on right, about half way down.

Have you ever dealt with them Gandalph? They were flagged red By McAdee site advisor, deal in Dollars or euros and seem to have strong Russian connections. But look as though they have a manual for the XR-C450, but no mention of RDS ( but aren't they all that these days?).

No, never heard of them until I did a Google search catgate. You could be right in your assumption that the segmented display is on it's way out. Without having the Radio in my hands to do certain tests, it's really just a guessing game. It could be the PLL synthesizer (the Phase Lock Loop controller) or a capacitor on it's way out, a bad earth, and I could sit here all night with speculations and it wouldn't help. It could be something restricting the correct amount of power from getting to the segment causing it be dim. That's why I mentioned the Schematic Diagram being important. The only other suggestion I can make would be to take it to a qualified auto electrician or electronic repair specialist. HTH.

Thanks for that, G. I will see if I can find a service manual somewhere, and failing that it looks like a repair shop.(Or trade in the car !!)

I'd trade in the car. :D

[Tankus]

and me

[catgate]

It's due for changing, but it had a new auto 'box in last year and a new Turbo this year so it will have to earn its keep a little longer. They no longer make a good car like they used to do.