Did you check for shorted outputs?
Are you sure that the rectifiers were in the correct locations?
Are you sure that the rectifiers were in the correct locations?
I just checked the speaker outputs on the PCB and didn't find any shorts either to ground or to each other. The rectifiers were put back in after the last time you asked me to remove them based on the pics I posted in the OP. At that point, the PCB had been untouched and as it was when it left the factory.
Measuring the resistance directly across the rail capacitors, do you read a short (constant 0 ohms) or does the meter slowly change readings (counting up or down)?
Just to be sure (I am the dumba$$ here, after all
) The rail caps are the two side by side in the center of the PCB, correct?

OK....Both are zero ohm. Also, Both were replaced a couple months ago when I initially replaced the IRFZ44s.
Generally, the only things that can make the rail caps appear to be shorted is shorted caps (obviously) and shorted rectifiers. If the rectifiers are not shorted, pull the caps to see if they're shorted.
I checked the rectifiers and the FEP16CT appears to be bad. Legs 1 & 2 show as passing in both directions. For expediency and cost, would there be a option for using two pair of "normal" diodes and replacing both rectifier chips?
You could possibly rig something to allow further testing but it wouldn't be possible/practical to substitute anything else permanently.
OK. I'll get to looking around the web to see if I can find the FEN16DT. That is the one that's good but I want to change out both. The FEP16CT (the bad one) I found at Mouser but not the FEN16DT.
Yea. That is the same conclusion I came up with and was going to ask you about. It seems that the FEN16DT from General Semiconductor is no longer in production. Fairchild is doing the FEP16CT and it stood to reason that the FEP16CTA was it's counterpart.
7 Months later and I FINALLY got back to this. I did the order to Mouser (I was waiting to get enough stuff for and order and still only had come up with about $40.00 worth) and replaced both rectifiers and WOOHOO......all is well, for the most part. After sitting for so long exposed, the gain pot is now dirty. Crackly even when not being adjusted. Sweeping back and forth a couple times confirmed that it was the pot. I looked on Mousers site and couldn't find a replacement so I guess I'll have to clean it and hope for the best.
PERRY....YOU ARE THE MAN!!!!!!!!!!!!!! 😀😀😀
PERRY....YOU ARE THE MAN!!!!!!!!!!!!!! 😀😀😀
- Status
- Not open for further replies.
- Home
- General Interest
- Car Audio
- Need help w/ old school HiFonics Pluto