This thread is going to be about the KE-4444 I bought in case the KE-1818 was dead. Unfortunately when I plugged the KE-4444 into my car, it did not turn on.
Without a wiring diagram, diagnosing it is going to be rather difficult. It is exhibiting the same symptoms as the KE-1818 did. No lights, no display, no nothing. I am hoping that it at least shares the same microcontroller as the KE-1818.
First step is going to be taking it apart and checking the silk screen to ensure pioneer didnt pull some sort of shenanigans and change the wiring between the two. If thats not the case, check for power at the switch. If thats good, check the microcontroller for power and signal (if its the same as the other unit).
If I cannot figure out the issue from there, I will need some help. I will do my best to take pictures of the boards. The KE-4444 has more boards in it (riser cards / daughter boards?) than the KE-1818 did.
Without a wiring diagram, diagnosing it is going to be rather difficult. It is exhibiting the same symptoms as the KE-1818 did. No lights, no display, no nothing. I am hoping that it at least shares the same microcontroller as the KE-1818.
First step is going to be taking it apart and checking the silk screen to ensure pioneer didnt pull some sort of shenanigans and change the wiring between the two. If thats not the case, check for power at the switch. If thats good, check the microcontroller for power and signal (if its the same as the other unit).
If I cannot figure out the issue from there, I will need some help. I will do my best to take pictures of the boards. The KE-4444 has more boards in it (riser cards / daughter boards?) than the KE-1818 did.
I was hoping to not buy it, but it looks like we have an actual issue with the radio.
Tried hooking it up to power and finding the power at the switch. Kept finding .24v, but no 13v.
I hooked it up to my meter in the amps setting, and it pulling very little power (like, .05A).
Started looking at the PCB and found a broken trace. Odd.. it prolly broke for a reason, but let's fix it and see what happens.
Fixed it, hooked it up using my meter as an amp gauge, and it immediately pegged my meter at +10A, and something started smoking around the area with the broken trace.
Got my big light out, and this diode (D607) is shorted and cracked. More than likely it's what started smoking as it started crackling, prolly from the flux I used that for through the through hole.
While I work on getting the manual, what could cause this? Prolly hard to diagnose without knowing what circuit it's in.
Also, does the IC looked odd to you..? I'm not sure if it burned out, or may be from something else.
Attachments
The diode is likely the RP diode. It likely failed because the radio was connected backwards (B+ and ground) with no fuse.
The radio will work without the diode but be careful not to connect the radio backwards.
The radio will work without the diode but be careful not to connect the radio backwards.
I pulled it, radio turned on. ALL of the backlights are blown, so seeing whats on the inverted 8 segment display is rather difficult. While looking at the display, I smelled something getting hot, followed by seeing a small wisp of smoke. Looked at power draw before disconnecting, 1.2A.
First thoughts were, check the output IC since thats where I saw the smoke coming from. Annnnnnd....it was the temperature of the sun.
If some bonehead did hook up the B+ and GND backwards, do you think it could have shorted the IC as well? With the toyota radios, the bad IC's also got scalding hot...
The output IC could have failed if the circuit opened and the protection of the RP diode was disabled.
You can read the display if you shine a bright light from the front of the display.
You can read the display if you shine a bright light from the front of the display.
What does the RP diode do?
Thats what I was doing. Trying to get the light at the right angle while holding the power lead on the power supply can be a fickle.
If I were to remove the IC, assuming nothing else starts smoking, should I be able to check the voltages and compare them to the KE-1818 radio, since they both use the same IC, to ensure the integrity of the rest of the circuit before blindly replacing the IC?
It's connected across the B+ and ground so that no current will flow when the power connections are correct but will short the supply if the supply voltage is reversed.
Would a 1N4007 diode be a suitable replacement for it?
I've ordered the manual from the link you provided, as well as 2 replacement output IC's and T1 LEDs.
Sounds good. I will drop one in and let you know how things go when I get the other replacement parts.
Manual wont be available to me till monday. Joe said that they've had a rough week and wont get to it till then,
Well, got the LEDs in. Removed the ke-1818 from my car to swap in the T1 LEDs, but decided to remove the output ic and drop it into the ke-4444 for now. I've got replacements coming in, so it's no biggie.
Replaced the bulbs, dropped in a 1n4004 diode as the RP replacement, dropped in an output IC and we have another functional radio! And actually, I'm quite happy with it. So much that I'm going to leave it in my car, and use the ke-1818 in my other tercel (despite the ke-4444 missing it's knobs). Reason being, I have a sub in my daily tercel and the ke-4444 offers more control over it than the ke-1818 with the addition of a scosche line out adapter (ke-4444 already has line out built in).
I appreciate the help as always, Perry Babin!
Replaced the bulbs, dropped in a 1n4004 diode as the RP replacement, dropped in an output IC and we have another functional radio! And actually, I'm quite happy with it. So much that I'm going to leave it in my car, and use the ke-1818 in my other tercel (despite the ke-4444 missing it's knobs). Reason being, I have a sub in my daily tercel and the ke-4444 offers more control over it than the ke-1818 with the addition of a scosche line out adapter (ke-4444 already has line out built in).
I appreciate the help as always, Perry Babin!
