A List of Small Mod(ification)s and Fixes
October 22, 2022 (last update: November 24, 2022)

Attention: The modifications or fixes listed on this page are described WITHOUT ANY WARRANTY. They may not work or may PERMANENTLY DAMAGE the original products. If the device is still under warranty, these changes also would VOID the warranty. So making these changes and using them is totally YOUR decision and you take a RISK. DO NOT modify electrical products if you think you are NOT QUALIFIED, and NEVER work on products when they are ENERGIZED. Always UNPLUG the devices and do not TRUST the power on/off switch on the device.

This is a list of small mods or fixes that I made to various devices. This page is mostly for myself, but I decided to make it public, it might be useful for someone. I plan to update it as I do new mods and fixes.

QNAP QSW-M1208-8C Fan Replacement

I am using this switch next to my desk. It is very silent, almost impossible to hear in daytime. However, it was bugging me in the night (when it is very silent around) when listening music. I thought maybe it needs cleaning but it did not change much. So I decided to try replacing the fans, it has two fans. It has Y.S.TECH FD124020LB-N fans, 12V DC, 4500 RPM, 6.08 CFM airflow and 2.81 mmH2O static pressure with less than 17dB(A) noise level. It is a 40x40x20mm fan with 4-pin PWM connector.

QSW-M1208-8C fan

Because I am looking for a silent fan, I look at Noctua, and NF-A4x20 PWM is pretty close, 5000RPM, 5.53 CFM airflow and 2.26 mmH2O static pressure with 14.9 dB(A) noise level. I am using the switch far from its maximum performance so I assume the small performance difference would not matter.

QSW-M1208-8C inside

Replacing the fan is simple but the original screws do not work with Noctua fan, and the screws that come with Noctua fan is a little hard to pass through the mounting holes but it works. The cable of Noctua fan is a little longer and the fan connectors are pretty close so there is a need for a little cable management.

I made the modification on an ESD mat and with an ESD wrist strap.

2022-11:04: After a few weeks, I should say this was a very successful mod for my need. I hear nothing in the night when listening music.

Stanford Research SR620 Frequency Counter Fan Replacement

I purchased an SR620 from eBay. It works quite fine but the original fan was making noise even after I cleaned it. It was a Delta DFB0624H 24V DC 60x60x25 fan. It is a bit difficult to find the data related to this fan but it looks like it is max 17.7 CFM and 4300 RPM.

SR620 fan

I purchased an ebmpapst 624M fan which has very similar specs, 17.7 CFM and 4550 RPM. Sound level is also similar.

SR620 inside

The fan is soldered to the mainboard of SR620. To not desolder old/solder new one, I initially thought just to cut the original fan cable and join the new one with a connector etc. After opening the unit, it does not look very difficult to resolder, it does not have other circuit elements nearby, so I did desoldered the old one and resoldered the new one.

I think the hardest part is to take out the old and put back the new fan because the space is a little tight, but it is doable.

I am not using SR620 very often, so I cannot comment if this is a perfect replacement, but I have not experienced any issue yet. Naturally the unnatural noise of the fan has disappeared.

I made the modification on an ESD mat and with an ESD wrist strap.

QNAP TS-932PX Fan Replacement

This is a 9-bay (5x3.5", 4x2.5") NAS. Its fan started to make some noise, I tried to blow off the dust but it did not change anything, so I decided to take a look at the fan and maybe replace.

At the end, it was not hard to reach the fan, however there are a lot of screws. First, I removed the 3.5" hard drives. Then the large part of plastic is unscrewed and removed, then the drive cage is unscrewed and removed and then the fan can be removed. It is a 140x140x25mm 12V fan with 4-pin connector, so a direct match to a Noctua NF-A14 PWM. It is a little hard to find the specs of the original fan but I think it has a little bit more power than NF-A14 (its maximum rotational speed is probably higher). I am not using the NAS extensively, so I think this would work fine for me.

TS-932PX with the original fan

I replaced the original fan with NF-A14 and put everything back together, and it works fine until now.

Pay great attention to plug back the hard drives in the original order.