18VDC PSU completely dead - ZD-915 desoldering station

[armini]

Hi everyone!

Three years ago I got a ZD-915 desoldering station which failed just after a few months of light use. During a short desoldering session, the station simply shut down, and since then it has been completely dead and unresponsive. The failure was silent, without any pops.

Due to a lack of time, I set it aside and didn't look at it.

Yesterday, I took it apart and did some basic measurements. The 18v terminal shows 0v. In addition, there is no visible damage to the board itself.

According to replies in 18VDC PSU has dropped to 10v - ZD-915 desoldering station, I concluded that a potential culprit could be the controller IC in these units, which is a CQ1565RT on my board. I bought the IC today, but haven't replaced it yet because I'm not certain that it is the problem.

I couldn't find a clear schematic for this PSU, so I feel like I'm going in blind. Any help in debugging this PSU is very welcome, and hopefully, end up fixing it.

Here are the front and back photos of the board:

[sam_sam_sam]

Re: 18VDC PSU completely dead - ZD-915 desoldering station

Read my post about this issue and make sure that you check the four diodes near the switching transformer for being shorted or open

Before you hook up the power cord to your outlet use an incandescent bulb in series or instead of the fuse and use something similar to a automotive type light bulbs use two bulb in series and make sure that it is not cycling with this type of load before you hook it directly to the outlet just in case you have another issue this is done with out the desoldering gun hooked up to the desoldering station

Do not be tempted to power the switching power supply board with out the heat sinks reinstall you will probably fry the switching regulator ic chip again or the other ic chip that is next to that one

Check and make sure that you do not have any type of short in the desoldering gun before applying power to the switching power supply board

If you have the switching power supply repeatedly cycling on and off check the controller board for heat on the surface mount capacitors because this is a known issue with the controller board as well ( this is with the desoldering gun hooked up )

I hope this helps you getting this issue resolved with your desoldering gun station