I'm currently working on a Chrysler/Infinity car stereo made by Mitsubishi. It came to me with the right front channel dead, and only half the display working. Got the display working no problem after resoldering some 40 bad joints throughout the deck, but would like a second opinion on the dead channel.
When turned on, the right front channel gives me a short chirp and then goes dead silent. The other three channels work fine. Power amp section looks to be real simple, consisting of 4 Hitachi HA1388 chips, with supporting circuitry looking to have been copied directly from the datasheet itself. When run for a while, the right front 1388 chip runs hotter than the others.
My question is, given how good the protection features on the HA1388 are, what are my chances I need to replace it? Methinks it's going into oscillation based on the chirp I get on power-up (not to mention the quality of the caps attached to that chip), but I'm not sure if I'll be able to easily get one of these 1388's to replace it.
The cap compliment is all Towa general purpose 85 degree. The replacements can be no more than 15mm high. I was thinking of using Nichicon HE to replace them, as they're the only thing I can find to replace the 4 15mm by 15mm 2200uf at 16v caps (might as well do all 4 channels while I'm in here). The HE replacements for the big caps are 18mm in diameter but I think I may be able to get them in there - alternate suggestions are welcome though. Going to do the two resistors on the dead channel as well, just in case.
When turned on, the right front channel gives me a short chirp and then goes dead silent. The other three channels work fine. Power amp section looks to be real simple, consisting of 4 Hitachi HA1388 chips, with supporting circuitry looking to have been copied directly from the datasheet itself. When run for a while, the right front 1388 chip runs hotter than the others.
My question is, given how good the protection features on the HA1388 are, what are my chances I need to replace it? Methinks it's going into oscillation based on the chirp I get on power-up (not to mention the quality of the caps attached to that chip), but I'm not sure if I'll be able to easily get one of these 1388's to replace it.
The cap compliment is all Towa general purpose 85 degree. The replacements can be no more than 15mm high. I was thinking of using Nichicon HE to replace them, as they're the only thing I can find to replace the 4 15mm by 15mm 2200uf at 16v caps (might as well do all 4 channels while I'm in here). The HE replacements for the big caps are 18mm in diameter but I think I may be able to get them in there - alternate suggestions are welcome though. Going to do the two resistors on the dead channel as well, just in case.
Comment