Chromatography Forum

Hi,

Been away from the repair end for quiet a while. PSU & LVPS are reference to the same part. When I adjusted the Voltage usually measured on the output side of the unit. Then adjusted to 5.1 to 5.2. Wouldn't go any higher than that. Blindly turning the pot a 1/4 of a turn will tell you nothing and could damage the LVPS.
If the fan is blocked or covered in dust then this can have the same affect. Need to ensure the air path from front to back is clear.

Thanks for your reply, the pot that I adjusted is on the power supply board WAS081324, there are a few input output on the board, labeled as "lamp", "power" and "thermal" on one side and "fan" on the other side. I looked at the power line and it looks like the "power" is for electric coming in to this board. so which output do you measure the 5V?

I here attached the link for pictures of the power supply board WAS081324 and low voltage power supply WAS081266 for your reference, I will appreciate if you can tell me where I should measure the voltage (5V). Thanks a lot

power supply board WAS081324
http://www.shop.apsonlinesite.com/WATER ... -80008.htm

low voltage power supply WAS081266
http://www.shop.apsonlinesite.com/WATER ... -80009.htm

Hi,

The 5 volts is adjusted on the low voltage power supply WAS081266. R43 is used to adjust it and on J2 the voltage is measured on the Red and black wires. So pins 2 & 4 of J2. Don't disconnect J2, just put the leads carefully down beside the wires, should be able to make connection with the crimped pin on the wire. Use a non metallic screwdriver to adjust R43, lots of high voltage present and don't remove the safety guard to get easier access.

Bull76

Hello, everyone, i have 2489 uv detector,this week i have reboot problem, i adjusted low voltage power supply to 5.3 volt, now my detector work proper, thank u every one.

Even after 15 years of the OP, still using 2487, the problem was the same. Thanx for the solution, increasing the pot.meter helped (from 23.3V to 24.5V measured on the red line), at least temporarily.