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

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#### Jason A

##### New Member
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!!

#### KMoffett

##### Well-Known Member
Jason,
I have a manual for a series of Proteck power supplies that includes the 3003. I scanned it into 20 PDF pages, and they ZIP into a 4.25Mb file. If you PM me with your email address (Do not post it here!) I'll send the file to you.

Ken

#### Jason A

##### New Member
Just wanted to bump this thread again. Ken has given me a great deal of input and help, but come to the conclusion that I need to grab the older schematics for my unit.

I just emailed Protek in hopes they come through but was looking on Ebay and just realized that the 3015b model, is basically what mine is doing.... going to 1.6a max as far as adj to..

Any thoughts? Both units are identically the same, transformer, etc... but there must be some component that regulates the AMP ADJ swing on either unit from 0-1.5a or the 0-3a

Mine is basically 0-1.5a right now

#### bfong129

##### New Member
Protek model 3003 power supply

I have a Protek model 3003 power supply the display and controls work but the output is fixed at 51V. I think the output transistors are shorted. Does anyone have a schematic for this power supply? Any help would be greatly appreciated. Thanks.

Brian F.

bfong129,

Ken

#### bfong129

##### New Member
Protek model 3003 power supply

bfong129,

Ken[/QU

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bfong129,

Ken

#### jhbowman

##### New Member
Ken,
I also have a Protek 3003 that needs repair & could use a schematic.
Joe

Ken

#### KMoffett

##### Well-Known Member
Joe,
I emailed the manual as a ZIP file. It's rather large...~4.3Mb. If you can't receive something that large, let me know.
Ken

#### Holtek

##### New Member
I am a owner of the power supply Protek 3003. Just like in the picture:

View attachment 61589

Unfortunately, there are errors in the schematic. Schematic does not agree with the state of the PCB. I found a few errors. But on my PCB is missing a few elements, something was modified. Do you have photographs of PCB mounted on the front panel? Can anyone do such photos?

View attachment 61590

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#### Holtek

##### New Member
I managed to get a fully functional Protek 3003 power supply. I disassemble all the parts, did a lot of measurements, corrected mistakes in the schematic. I did a lot detailed photos. My power supply is already fully working. Fantastic
Photos and corrected schematic diagram: **broken link removed**

Best regards.

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#### KMoffett

##### Well-Known Member
Wow! Great work. I'm sure your efforts will help others.

Ken

#### ralfie53

##### New Member
Do you still have the manual?

Ken

#### LEVITHOMAS

##### New Member
Protek 3005B repair manual

I have the repair manual for the Protek 3000 series power supplies. (I own the
3005B, 30 volt 5 amp) It contains all the schematics and parts lists for resistors, caps, diodes etc, it also explains calibration techniques. I would gladly share this with anyone who needs it. I also need to know how to access the Picasa page that Holtek has, I click on the power supply picture and nothing comes up. can anyone help me. Thank you.

#### DHolub

##### New Member
Jason,
I have a manual for a series of Proteck power supplies that includes the 3003. I scanned it into 20 PDF pages, and they ZIP into a 4.25Mb file. If you PM me with your email address (Do not post it here!) I'll send the file to you.

Ken
I am in need of the schematics for the 3015B but i cant seem to find out how to PM you to give my e-mail address...????? I have the service Manual but it does not include the schematics.

#### JimB

##### Super Moderator
At the top right hand side of the screen is a button with your name DHolub, click on the button, this should drop down a menu with several options one of which is Converstations.
Click on conversations and then click on the Start a new conversation button, and start a conversation with KMoffet.

JimB

#### KMoffett

##### Well-Known Member
I am in need of the schematics for the 3015B but i cant seem to find out how to PM you to give my e-mail address...????? I have the service Manual but it does not include the schematics.
It's on it's way.

Ken

#### DHolub

##### New Member
Protek model 3003 power supply

I have a Protek model 3003 power supply the display and controls work but the output is fixed at 51V. I think the output transistors are shorted. Does anyone have a schematic for this power supply? Any help would be greatly appreciated. Thanks.

Brian F.
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

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