bk precision 1550 repair

[saibot1988]

Hello guys,

today I killed my power supply bk precision 1550.
I made a unwanted connection between Postive (voltage was set to 3v3) and the Ground of the USB Port.

After I big bang and lot of smoke I opened the supply and found a exploded Transistor Q11 (MPSA44) and a completely burned resistor R63.
I tested also the Transistor Q12 (2SA950) and came to the result that Q12 is defective too...

I can power on the supply, but it shows CC at the lcd and it is not possible to adjust the voltag.

Does someone have a service manual of this power supply or know the value of the burned resistor R63?

R. I. P my loved compact Power Supply

[MikeK]

Did you ask BK nicely?

[saibot1988]

Yes, but till now I don't got a feedback.
I found that this power supply is equal with with following models.

TENMA 72-8345
MANSON NSP-3630
Voltcraft LSP 1363

For the Voltcraft I found a schematic

https://asset.conrad.com/media10/add/160267/c1/-/en/000515266CD01/circuit-diagramm-515266-voltcraft-lsp-1363-bench-psu-adjustable-voltage-1-36-v-dc-015-3-a-100-w-no-of-outputs-1-x.pdf

https://www.eevblog.com/forum/testgear/bk-1550-based-on-same-design-as-tenma-72-8345-and-manson-nsp-3630/

https://www.eevblog.com/forum/repair/voltcraft-lsp-1363-power-supply-no-output/

[saibot1988]

After replacing the two Transistors and the burned Resistor the Power Supply is working again