APC SMT750I Quick Teardown

[@SW-lj4so]

Hi, Nice video and explanations. I couldn’t quite see from the video but are the serial connections for the apcusd connections part of the main motherboard or a separate daughter board?

[@kriskotooBGXD]

Quite interesting. I have a unit with me now thats having a rather weird issue. When connected to power, no matter what load is plugged into it it says that fhe load is 0. If it tries to go to battery power, the relays click, and it goes into a fault of "No Ouput Voltage", "Power Overload". I decided to measure some voltages and it seems that the battery terminals are at around 17v without the battery connected, and digging further i dound out that fhe small supply board is producing the 17v. I wonder if this is correct, or the low voltage is causing logic issues

[@ITTFami]

Now, this is the content I subscribed for. I really like your old videos that have to do with batteries/UPS. Bit of a question: I have a Back-UPS CS 500 (With all the small caps replaced to eliminate the whine, gotta thank you for that tip) from 2006 or so. Is it one of the models that have the transformer online all the time?

[@FFcossag]

No, the plastic back-UPS models are offline, not line interactive.

[@cristalolahansalak3813]

So this is bad ups for Corsair psu?

[@johnstouchpad6437]

8 years is good. I like the SMT1500 model.....

[@zx8401ztv]

Well worth your time and effort f.f, a lot of people trust apc units to be reliable. Yes tny switchmode all in one chips do tend to go poof, i like a big stonking mosfet on a good heatsink and a seperate control system for switchmodes. i'm old fashoned and don't think heat is good for any device.

[@johnstouchpad6437]

I like the smt1500 model...

[@khachaturian100]

Beware of both Epcos and Illinois Capacitor. Once good, now dubious at best. Thanks, liked.

[@c4osc]

Hi FF. Since you have a lot of experience with these devices, is there an easy way to connect 12V/24V fans to this model? e.g. any free pins on the mainboard?

[@FFcossag]

You can shove 24 V fans straight across the battery terminals, but that's about it. I think there's also a relay breaking the battery, but I'm not sure. The 12 V regulator is very weak, so you shouldn't try to run a fan off of it.

[@c4osc]

That relay would be the best place if I can figure out where it is. Think you used that for a fan on another series as well. Guess just grabbing some 12?V at the smart slot will count to “not recommended” in case it’s related to the 12V regulator. Thanks for the input. Great videos man.

[@electronic7979]

Nice video 👍 very good

[@hassnbasem2403]

Please help .... Hello ... I have a ups apc size 1000 av, linked to the battery car number 2 (24 v) volume per 70 amp, but the stream shipping few ranging from 4 to 5 amp, no more. Do you I could connect two ups on parallelism in order to increase stream shipping (reduce charging time) . . . I personally you experimenting this process and succeeded rather, has doubled stream shipping, but in the long run don't know is possible that i'm having a problem? ارجوك helped me ... we suffer a lot of blackout and thank you

[@twocvbloke]

Ah crappy caps, the bane of modern electronics, it does make me wonder if they use them intentionally, not just for cost-saving, but to kill the products sooner so we end up buying a new one unnecessarily, but that's just the cynical side of me at work... :P

[@FFcossag]

No, you are quite right.