Baked? An FV-1/eeprom query

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Diynot

Well-known member
Long story short, the L78l33 in a recent HAARP build is putting off 6.7v to the eeprom and FV-1. The effect is there, just distorted when hit with the lower strings. How long can these chips withstand that voltage, are they baked now? Data sheet says max v for the FV-1 is like 3.5v. 5.5v max for the eeprom😬. Also, is there a way to divert the voltage from the FV-1 while I troubleshoot? A jumper from pin 6 to ground perhaps?
 
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Diynot said:
Long story short, the L78l33 in a recent HAARP build is putting off 6.7v to the eeprom and FV-1. The effect is there, just distorted when hit with the lower strings. How long can these chips withstand that voltage, are they baked now? Data sheet says max v for the FV-1 is like 3.5v. 5.5v max for the eeprom😬. Also, is there a way to divert the voltage from the FV-1 while I troubleshoot? A jumper from pin 6 to ground perhaps?
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have you tried replacing the L78L33 with another one?
 
owlexifry said:
have you tried replacing the L78L33 with another one?
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That is my intention if visual inspection and solder reflow doesn’t bring the voltage back into line.
Edit: that is if I didn’t ruin the FV-1 and eeprom otherwise I just need to start a new board
 
Since there are very few parts in the 3.3v supply it wasn’t hard to validate that everything was good as far as components and soldering. Had one L78l33ACZ left from my last Mouser order so decided to breadboard it first and sure enough, sucker is putting out 8v from an 8.99v supply. Check your components before you drop them in people.

OR the pinout is backwards from the data sheet IMG_5246.jpeg
IMG_5247.jpeg
Someone call me out big monk style if I am just fucking crazy

Nope nope I did the same damn thing. The pinout is a bottom view 🤬
 
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Same has happened to me and luckily I noticed it before socketing those sensitive programmed ICs in the build. Good reminder to always check sockets with DMM before going further and double check pin orientation on transistors from datasheet and with a tester.
 
JohnnyCreepy said:
Same has happened to me and luckily I noticed it before socketing those sensitive programmed ICs in the build. Good reminder to always check sockets with DMM before going further and double check pin orientation on transistors from datasheet and with a tester.
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Well, yes, always check your parts and MOST IMPORTANTLY, check the damn orientation on the silkscreen. The regulator was fine, it was my dumb ass who put it in backwards🫠. Good news is the FV-1 and eeprom seem to be ok.
 
Diynot said:
Well, yes, always check your parts and MOST IMPORTANTLY, check the damn orientation on the silkscreen. The regulator was fine, it was my dumb ass who put it in backwards🫠. Good news is the FV-1 and eeprom seem to be ok.
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Uhm, Yeah, I've soldered in a regulator backwards more than once.

I have one FV-1 on a breakout that took 12 volts. I am amazed that it still functions. I only use it on the bench to breadboard an idea.
 
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