Protek 3003b not adj to full current (3A)

[DHolub]

Hi everyone! Found this great site to plan hopefully to add to the community here!

I have a Protek 3003b which I've plugged in 2 days ago after sitting almost all year and noticed it only adjusts to about 1.7 amps

Pulled it down to the frame and looked around and cannot find any thing wrong or nothing appears to be blown on the front control board or the power supply board. Everything works smooth, just instead of the "Aadj" going from 0-3a it now pretty much goes to 0-1.7a or so...

Strange that this being such a popular benchtop PS and still pulling in a pretty $$$ that I cannot find anything on the web...

Any help would be greatly appreciated !!!

Thanks!!

You probably have one or more of the op-amps gone bad. Common problem. Just replace them all, they are very inexpensive. Install IC Sockets first. The power supply will probably require calibration after replacement.
Don

 

[DHolub]

I still have not received the manual requested.
Thanks,
Don

 

[DerStrom8]

Brian...
If the outputs were shorted, the voltage would be probably be at max. I doubt that s it. These are very common for the op-amps to go bad. Just replace them all, they are very cheap. I have (at the company) about 7 of these power supplies and have had to replace them all in every one. HINT: Install IC Sockets, they are cheap too.
Don

I just wanted to point out that this thread was started in 2010. Chances are the OP moved on a long time ago

Matt

 

[KMoffett]

I still have not received the manual requested.
Thanks,
Don

Don,

Sorry I sent to someone else that had requested it. Should be on the way now.

Ken

 

[Jason A]

I just wanted to point out that this thread was started in 2010. Chances are the OP moved on a long time ago

Matt

LOL no.. heck no! I'm still here, just been VERY busy and active in the EV life style the last few years! Got a Rav4EV and a Tesla now so enjoying those.

What sucks big time and to bump this thread is my 3003b just fell off a tall shelf a few days ago and the main board on the side broke right in 2!

I've been using her all this time with the reduced amperage! But now I'm going to have to replace the whole thing :-(

Unless there are whole boards and parts avail??

Funny thing is, I just got a Fluke 287 and those meters on the front were dead on with the 287 (certified calibrated)..

So sad

 

[tehbard]

if anyone still has the manual available

Dan

 

[KMoffett]

Yes, I still have the file. Not good a fhing to post email addresses. Spy bots will find them and Spam you, Go back and remove them. Send me a "Private Message".
Ken

 

[tehbard]

all better? tough doing on my new phone, still getting used to it

 

[KMoffett]

PDF file sent.

Ken

 

[2bluesc]

Did anyone find the schematics for the 3015B? The control board is quite a bit different (opamps, trim pots) then the 3003B board. The control board and display board is marked "C30S-4".

One of my supplies only goes to 0.15A and the other goes to the expected 1.5A. Tested with a current sink and it's the actual regulation, not the display.

Picture attached and a high resolution image on Imgur for those interested.

 

[mihai]

I have a Power supply Protek 3003d with problems. If anyone still has the manual available for this model.

Mihai

 

[KMoffett]

Mihai,

Send me you' re mail address by Forum's "Private Mail" and I will send you the manual as a PDF. Do Not post your email here.

Ken