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Hi All
Could anyone tell me if it’s possible to bench test a ‘modern’ type radio. Is it a case of connecting everything up or is it part of a more complicated system? Unfortunately I don’t have a harness so I’m unsure of the terminal connections.
The Radio is: AJ9850R Part No LJB4100AA.
Any advice and ideas would be most welcome.
Thanks
Pete
Last edited by PDMiller; Sep 16, 2021 at 12:47 PM.
I think you will get a better response to this question in the Model forum so I've moved it from Audio/Visual Electronics to XK8/XKR forum.
The Electrical Guide shows harness details but your problem is likely to be actually making connections. The simplest way is to obtain a connector with around 20 cm of harness. I've found Eurojag at Darlington very helpful in supplying various connectors cut from scrap vehicles. As you are in Northumberland, they are also your nearest specialist Jaguar breaker.
Also, you could get the connector new, depending on what you want to do with the unit (power it up?, check inputs and outputs?). You may find, at some point, that the 10 minutes needed to open the console and use the car as the 'bench test device' might be the way to go. But, the standard wiring diagram from 2000 is attached, the power connector (IC19 on the diagram) is a 12 position multilock 070 available from Mouser.uk. Pins (sockets here) also
Thanks Crbass
My car actually has a later unit: AJ2050W Part No: LJD4100AA and the screen has stopped working. The unit I want to test has different connections and a known fault but the same screen which is believed to be good.. I was hoping to test the older unit before attempting a transplant. It looks straightforward with a multiplug and 2 soldered support clips but pride comes before a fall and I anticipate it being less simple than it looks.
Thanks again
Pete
Latest update.
I changed the screens and now nothing works. The old screen would light up when the radio was switched on but now it doesn't and replacing the original screen gives the same result, .
Tried entering the code but flying blind so I don't know if the radio is switched on or off.
Any ideas anyone?
Last edited by PDMiller; Sep 19, 2021 at 01:39 PM.
Checked the fuse in the passenger fuse box, don't know of any others but will check it out. Maybe the next thing is to pull the radio out again and check all the connections. I have a feeling that I've wrecked it by changing the screen but not sure how. Life was simple when everything had 2 or 3 wires and a fuse.
I would check that you have power and ground to the radio at the harness.
Now that you might have destroyed it, you can safely test it on the bench without worrying about destroying it - try giving it 12v on the work bench using mini crocodile clips on the connectors, or directly inside.
This is the screen on the doner radio LJB4100AA. The mountings were twisted slightly and soldered. My radio is LJD4100AA but the screen numbers are the same
A couple of questions
In the area marked 1. Are the two pins bridged in any way (i.e. solder crosses the gap on the board)? The board around these pins appears to be corroded? And did these connect with the through vias below (the holes in the supporting board?
In the area marked 2. There appears to be a free hanging pin right above the connector? Is this just an optical illusion or did this connect to something? Also, there is a pile of solder near the yellow 2 that I added. Is this a ground to the board below?
In the area marked 3. Same questions as for 1, except the traces leading below the lower pin are intact? Or cut and/or bridged?
Right under the 4 appears to be another pile of solder. Is it obvious why this is here?
Also, the supporting connections to the rest of the unit, do any of these appear to be connected with the ground plane (solder or open copper)? Maybe that's what is happening with the solder on the support in your lower picture? Was that originally bent and connected with solder?
Morning from sunny Northumberland crbass
Thanks for the info. I'll check it out later and maybe get a better photo. I noticed on the wiring diagram that ground is by a braided lead on the older model. I've been using terminal 13 as per the connector diagram but maybe an earth connected to the radio chassis is worth a try.
The car will be laid up for Winter from the end of the month so I'll strip the original radio out then and concentrate on that one. I thought it would be an idea to power up the doner set to make sure that the screen worked but what I thought would be a 15 min job has turned out to be more involved than I thought.
A friend tells me that when powering up a radio the speakers should be connected or it's possible to wreck the set??? I had one speaker connected but might I have done some damage by not having the other 3 connected. I think this theory is unlikely as a wire pulled off a speaker by mistake would write off the radio.
Thanks again for the advice and I will return with photos
Pete
latest update
I pulled the radio that's in the car today, checked all the connections which were as they should be, connected it back up and lo and behold it worked. After entering the code there was data on the screen and everything worked as it should. I put everything back and ran it all afternoon while I was pottering in the garage. Switched it off and back on again and you guessed it, everything still worked but the data had disappeared. . I tried the replacement screen and it didn't even light up so I'm back on the original screen, flying blind but at least I can use the radio. The soldering on the original screen PCB is the same as on the replacement but much neater so I guess someone has been at it.
Now that I know that the replacement screen is US I'll put up with no data till a better unit comes along.
Thanks for the help and advice
Pete
Bench test XK8 Radio
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