Dodgy Repair found in HP6012A Power Supply

[Blastcap]

... File off the rusty bits and fill the holes with solder!

If it works on cars, why not on electronics?

[Fraser]

I have seen this done once before when a TO3 transistor could not easily be removed due to it being riveted into a closed chassis. Someone elected to trepan the TO3 to get the lid off, and then fitted a TO220 to the internal connections. In that case the TO3 lid was not refitted so it was obvious what had been done. The TO3 became just a surface mount 'PCB' for the TO220 transistor and its heatsink. This is not an approach that I subscribe to, except in an emergency, but it was in Australia and such unorthodox repairs were commonly known as 'Bush Engineering'

Fraser

[Jay_Diddy_B]

Hi,

The MOSFET has a drain connection. May be they called a plumber to fix it ?? 

Regards,

Jay_Diddy_B

[Len]

This is not an approach that I subscribe to, except in an emergency, but it was in Australia and such unorthodox repairs were commonly known as 'Bush Engineering'

"She'll be roit, mate!" (I've been watching EEVBlog so long, I'm almost bilingual.)

Jay_Diddy_B, please open it up and end the suspense!

[Jay_Diddy_B]

Hi group,

The can has been un-soldered. Here is the picture:



As I suspected, a good silicon die.

I opened another IR 1855-0473 and it looks identical:



So there was no tampering inside the package.

Here is a photograph of the Motorola version of the 1855-0473, a damaged one:



Notice how the die is mounted on an angle. This is to get the center of the die closer to the center of the package.

Regards,

Jay_Diddy_B

[setq]

I can only conclude the previous owner was nuts 

[Jay_Diddy_B]

I can only conclude the previous owner was nuts 

If he was rich, he could have been eccentric. 

Regards,

Jay_Diddy_B

[TheSteve]

Maybe Dave used to own it and decided instead of turning it on, he would take it apart.

[voltz]

Glad you replaced it.. Even if the device was working, you've done the right thing by replacing it with a new one.

conclusion: maybe the device was opened by someone who just wanted to see what it looked like inside. Thats all.

[deepskyridge]

Transistor Stuffing.

Gary

[lowimpedance]

Maybe Dave used to own it and decided instead of turning it on, he would take it apart.

I think your right !  .
Don't turn it on.......CUT it aparrrrt...

Obviously who ever did this takes curiosity to the extreme .

[bitseeker]

Fascinating. Thanks for the show-n-tell, Jay!

[Kjelt]

Normally the NSA does a better job hiding its bugs 

[VK5RC]

Wasn't just cut apart looked like they had used a can opener or maybe his teeth. 

[setq]

Wasn't just cut apart looked like they had used a can opener or maybe his teeth. 

Haha.

Hold my beer.... https://youtu.be/tmnFyiPmkNM?t=738 ... but TO3's...

[setq]

Actually I think I've worked out why this was done. He was clearly looking for Transistor Man!